text:
\section{Introduction \& Background}
Energy is key for the well-being and development of all societies. Especially Small Island Developing States (SIDS) are facing numerous social, economic and environmental challenges when it comes to energy. The UN Conference on Environment and Development in 1992 provided the first definition for this distinct group of developing nations geographically located in the Caribbean, Atlantic, Indian and Pacific Oceans \citep{robinson_adapting_2018}. They are characterised by small geographical areas, insularity, remoteness and are prone to natural disasters as well as the negative impacts of climate change \citep{pelling_small_2001}. The small island character creates limited markets, often with erratic domestic revenues, which are further exacerbated by high costs of public services \citep{briguglio_small_1995}. Smaller market size in comparison to larger developed nation counterparts makes diversifying conventional power generation almost impossible, which favours large utility monopolies. In addition, most SIDS lack natural fossil resources and have difficulty diversifying economically, resulting in a high import demand for strategic goods \citep{undp_high-level_2018}. Many SIDS experience heavy fiscal burdens, limited sources of foreign exchange, dept accumulation and a heavy dependency on external aid and donors, while being almost 100~\% reliant on fossil fuel imports \citep{atteridge_development_2019}. Another crucial challenge is the financial dependence on bilateral or multinational loans \citep{oecd_making_2018}. These factors, along with the ubiquitous pressures of global warming and the need for CO\textsubscript{2} mitigation, urge SIDS to redirect fossil fuel spending to other critical areas. This twin challenge could be addressed through a sustainable transformation of the energy sector. SIDS, including Barbados, are playing an increasingly important role pushing for climate action. With a dependence of more than 95~\% on fossil fuel imports, Barbados faces economic vulnerabilities that translate into high electricity prices \citep{henderson_sids_2013}. At the same time, Barbados is the first island in the English-speaking Caribbean to commit to using 100~\% renewable energy \citep{henry_key_2015}. The heavy reliance on fuel imports for energy generation and transportation has affected and is affecting the nation's economic growth and social development. According to \cite{robinson_adapting_2018}, the main incentive behind a shift from (imported) fossil to (local) renewable energy sources is economic survival, rather than climate change mitigation. Barbados has favourable wind and solar resources to aim for a high share of renewable energy sources in the electricity sector as well as the potential to electrify other relevant fossil based sectors.

Most energy system modelling at the international level and in the SIDS is done with closed black-box energy system models (ESMs). Typically, these are pre-set models and the source code is unavailable for third party review \citep{pfenninger_long-term_2016, hilpert_open_2018}. This makes the analysis of the raw data and the methods used impossible for external analysis, especially for policy planning agencies and researchers. However, under the principles of the Open Energy Modelling (openmod) initiative, the data and code for the model used in this analysis is shared publicly. Open science should be the standard to promote transparency in scientific investigations. Increased openness is also significant to foster open and frank dialogue between SID state governments and the lending agencies that often require energy modelling investigations as a prerequisite for policy based loans \citep{atteridge_development_2019}. Whereas only a few studies address the possibility of a 100~\% RES for Barbados, none utilise an open source energy system model to create transparent and reproducible results. This study fills the above mentioned research gap by developing an open energy system model based on the Open Energy Modelling Framework (oemof) \citep{hilpert_open_2018} for Barbados. This allows to determine, which share of renewable energies is technically and economically feasible in the future electricity system of Barbados in 2030, as well as modelling not yet electrified sectors, passenger transport and cruise tourism sector.

\subsection{Energy system}
The Barbadian electricity system relies almost entirely on imported fossil fuels. In 2020, 95.4~\% came from oil and diesel, with heavy fuel oil as the primary fuel source, followed by kerosene and diesel \citep{healey_energy_2020}. There is a total of three conventional generation sites referred to as Spring Garden (153.1~MW), Garrison Hill (13~MW) and Seawall (73~MW) \citep{blp_integrated_2014}. Fuel as input for generation changes depending on the annual oil price and the subsidy structure \citep{gob_barbados_2019}. Spring Garden therefore uses heavy fuel oil, whereas the gas turbine at Garrison Hill and Seawell are operated on diesel fuel \citep{espinasa_achieving_2016}. The total installed capacity in 2018 was therefore 286.6~MW, with a share of 10.5~\% of installed renewable energy in the form of photovoltaics (PV) \citep{irena_renewable_2019}. In 2015 only 2~\% were supplied by renewable energy \citep{gob_barbados_2019}. There is a 100~\% access rate to electricity and Barbados continues to have a reliable power supply with fewer blackouts than other regional territories according to \cite{espinasa_achieving_2016}. The energy demand by sectors breaks down to 41~\% electricity generation, 27~\% transportation, 10~\% commercial and public, 9~\% industry, 9~\% residential and 5~\% other \citep{irena_barbados_2016}. The retail energy price in Barbados, which can rank among the highest in the Caribbean, varies significantly with the price of international oil and is allocated to energy consumers through the Fuel Clause Adjustment \citep{gob_barbados_2019, henry_key_2015}.

The peak demand and total generation were examined in several studies solely as formal statistics as the figures are not released to the public. Between the period of 1993 to 2013, the peak demand grew from 92 to 152~MW and reached a maximum of 167.5~MW in 2012 \citep{espinasa_achieving_2016}. Between 2014 and 2019, the peak demand oscillated between 150 and 155~MW, which fits the \citep{irena_barbados_2016} estimate of 158~MW peak demand in 2015. In 2018 the peak demand were 152.3~MW, which corresponded to a total generation of 996~GWh/a \citep{healey_energy_2020}. The slight drop in the peak demand within recent years can be attributed to limited economic growth and the expansion of distributed PV generation \citep{espinasa_achieving_2016}.  \cite{hohmeyer_economic_2017} puts the total demand in 2013 at 912~GWh/a with a total production of 970~GWh/a. Accordingly, \cite{irena_barbados_2016} reports a generation of 1090~GWh in 2015. Official government estimates show that in 2019 and 2020 the total generation was 943~GWh and 893~GWh per year respectively. The significant drop can be attributed to a rapid contraction in economic activity, specifically, within the tourism industry due to the COVID-19 pandemic \citep{research_department_energy_2020}.

\subsection*{Wind and Solar}
Weather conditions in Barbados are promising for a cost efficient RES. According to \cite{alleyne_100_2014}, the wind resource is steady, constant and reliable in direction due to the trade winds. The wind speeds range between 4.8 and 8.0~m/s at 10~m hub height. For potential wind energy developments, based on data from 2000 to 2019, an average capacity factor of 36.97~\% was calculated. However, during this period, the average capacity factor of all lowest months in each year is only 19.7~\%. The reason for this difference is the specific characteristic within the temporal dynamic of wind, which drops in the months September and October. The dynamic is shown in Figure \ref{fig:capacity-factor} based on selected weather years. \cite{hohmeyer_100_2015} states a theoretical potential of 4.3~GW which needs to be reduced to a technical potential of around 600~MW for wind energy deployments. The Government of Barbados \citep{gob_barbados_2019} state a maximum of 150~MW wind onshore and 150~MW wind offshore for 2030. \cite{rogers_desktop_2017} conducted a study using WindFarmer Pro analysing the onshore wind resources in Barbados, recommending a total of 472~MW of installed wind capacity.

\begin{figure}[!h]
    \centering
    \includegraphics[width=0.9\textwidth]{figures/wind_solar_analysis.pdf}
    \caption{Average wind and solar daily capacity factor and 95~\% confidence interval of four years (2002, 2004, 2010, 2014) based on \emph{Renewables.Ninja} \citep{pfenninger_long-term_2016} data for location at 13.32 latitude and -59.6321 longitude.}
    \label{fig:capacity-factor}
\end{figure}

The (average) daily solar capacity factor is significantly lower but more constant over the course of the year compared to the capacity factor for wind. \cite{hohmeyer_economic_2017} estimates an average solar irradiance of 2,196 kWh/m\textsuperscript{2}, which peaks from April to August and falls of slightly from August to December \citep{alleyne_100_2014}. This trend is in keeping with the rainy season that would be characterised by partly cloudy skies and a slight reduction in the solar irradiance \citep{field_effect_2015}. Presently, over 95~\% of the installed renewable energy grid-connected systems on Barbados are PV installations \citep{caricom_energy_2018}, which are about 40~MW of distributed PV, including a 10~MW solar farm in the north of the island. \cite{irena_barbados_2016} estimates the solar energy generation in 2017 at 30~GWh. The total solar potential for 2030, estimated by \cite{gob_barbados_2019} is split into 205~MW solar centralised and 105~MW solar decentralised. \cite{hohmeyer_100_2015} states a theoretical potential of 200~MW, requiring an area of 1.6~km\textsuperscript{2}.

\subsection*{Bioenergy}
The relevance of bioenergy for a 100~\% RES in Barbados to complement the wind and solar potential was stated inter alia within \cite{espinasa_achieving_2016, gob_barbados_2019} and \cite{irena_barbados_2016}. Considering that the island has an extensive natural gas network, that supplies one million cubic feet per day to the public, the Government of Barbados has recognised the possibility of supplementing the natural gas mix with biogas \citep{gob_barbados_2019}. Historically, Barbados has always been a high-cost sugar producer, due to the lack of economies of scale and costs associated with growing sugar cane locally \citep{mitchell_sugar_2005}. Therefore, bagasse as a residue from the sugar production process can be used for the generation of bioenergy. \cite{marshall_bio-digestion_2019} confirmed that 1.5 million m\textsuperscript{3} of biogas could be produced from guinea grass, through anaerobic digestion. \cite{irena_renewable_2019} estimates a biomass potential of 54~MW. All analysed studies agree, that the determinant factor is the available area for biomass. According to \cite{undp_preliminary_2009} Barbados had 8,000~ha under sugar cane cultivation as of 2010. The total arable area was estimated at 19,000~ha, whereas 30~MW of production capacity could be met with bagasse, cultivated on 1,610 to just over 2,000~ha.

The island has a significant problem regarding the management of waste as approximately 900-1000 tonnes are sent to the landfill, of which about 300-500 tonnes are municipal solid waste (MSW), that could technically be used for waste-to-energy recovery \citep{marshall_bio-digestion_2019,rj_burnside_international_preliminary_2014,simmons_and_associates_barabados_2015}. However, these estimates have not been supported by large-scale feasibility studies or pilot projects. In 2014, a 3~MW waste-heat recovery plant was installed and \cite{irena_barbados_2016} assumes a possible production of 10.57~GWh in 2030. \cite{hohmeyer_economic_2017} estimates a higher possible capacity of 11~MW solid waste combustion in 2030. The \cite{undp_preliminary_2009} analysis estimates around 365,000 tonnes of raw material to be used in a production capacity of 3-5~MW.

\subsection*{Cruise Ships \& Electric Vehicles}
The electrification of sectors, which are traditionally powered by fossil fuels is being pursued. According to \cite{schuhmann_visitors_2019}, tourism had a total contribution of almost 40~\% to the GDP as well as the national employment in 2015. In 2018, more than 800,000 cruise ship passengers were recorded in Barbados \citep{bpi_port_2020}. The cruise ship industry is a substantial source of noise and air pollution, emitting NO\textsubscript{X}, SO\textsubscript{X}, GHG and particulate matter emissions, especially when the ships are berthed in the harbour \citep{lind_potential_2018, endresen_emission_2003}. The increased health burden from the resulting air pollution can lead to increased cases of illnesses such as asthma and respiratory infections, which burden the health system and the well-being of the population in the country with additional costs (for further reading, please refer to inter alia \citep{zis_evaluation_2014, tang_impact_2020, viana_estimated_2020, rabl_public_2000}). A more sustainable alternative are shore-to-ship power connections, which use the onshore power grid to meet the berthing power demand of ships. This concept has the potential to reduce CO\textsubscript{2} and air pollutant emissions substantially. Considering the sector's importance for economic development and as a regular seasonal energy demand, it is vital to be incorporated into energy related studies and energy system modelling. However, according to \cite{irena_barbados_2016}, cruise ship companies have expressed their doubt and reluctance to use such shore-to-ship power connections. Also, the Government of Barbados \citep{gob_barbados_2019} doubts the possibility to electrify cruise tourism, arguing, that resulting GHG emissions are not attributable to the host country alone.

As an island system aiming for 100~\% renewable energy and due to air quality considerations, it is apparent to include the passenger transport sector in the modelling approaches. According to \cite{irena_barbados_2016} 81.5~\% of all registered vehicles are privately owned passenger vehicles, which could easily be replaced by similar classed electric vehicles.

\subsection{Climate Change and Energy Policy}
As most SIDS, Barbados is highly vulnerable to climate change as the atmospheric temperature increases, sea levels rise and weather patterns change \citep{undp_barbados_2020}. The island has therefore not only committed to several overall sustainable development goals as a member of the SID Group of Nations, but has also developed a Nationally Determined Contribution to reduce greenhouse gas emissions. Specifically, this includes the formulation of a Nationally Appropriate Mitigation Action (NAMA) as described in the Sustainable Energy Framework (SEF 2010), aimed at connecting the mitigation of climate change to a broader sustainable development for the energy sector. At the same time, Barbados's contribution to anthropogenic GHG emissions have been minuscule in relative and absolute terms. With regard to CO\textsubscript{2} emissions, controversial values are stated within the literature. A study by the government of Barbados \citep{gob_barbados_2019} puts per capita CO\textsubscript{2} emissions at 29.5~t in 2015, whereas in 2016, the total CO\textsubscript{2} emissions were about 1,276 kt, with 4.5 tCO\textsubscript{2}/capita according to \cite{macrotrends_barbados_2021}.

As the pursuit of higher shares of renewable energy sources is not primarily climate change related but also a facilitator to address economic and fiscal challenges caused by the high dependence on imported fossil fuels, the Government of Barbados has committed to transforming the entire energy sector, including electricity generation and transportation \citep{irena_barbados_2016, gob_barbados_2019}. Consequently, the most recently approved Barbados National Energy Policy (BNEP) for 2030 by the Ministry of Energy and Water Resources wants to diversify the energy sector, whilst aiming at a 100~\% renewable energy-based system in 2030 under the keywords diversity, efficiency, affordability and collaboration \citep{gob_barbados_2019}. The 2030 agenda calls for an elimination of the use of fossil fuels for the local transport sector, switching to bio fuels or increased electrification.

\subsection{Research Question}
The Barbadian situation puts a strong emphasis on climate change mitigation because of the small island characteristics and economical challenges connected to the fuel import dependency. The research questions in this paper are connected to a techno-economic assessment of the energy future of 2030 and built on \autoref{state_of_research} and \autoref{sci_contribution}. For this purpose, an open source model based on the Open Energy Modelling Framework (oemof) was developed, aiming to answer the following research questions:

(1) What is the cost-optimal share of renewable energy sources technically feasible for the Barbadian electricity system?

(2) What are suitable combinations of storage technologies and particularly the role of PHS in a 100~\% RES for Barbados?

(3) What are the techno-economic effects in the electricity system due to the electrification of the passenger transport sector and shore-to-ship power supply for cruise ships in Barbados?

\section{State of research}
\label{state_of_research}
Several studies have highlighted the impact of fossil fuel dependency on the SID state characteristics that directly and indirectly exacerbate the need for sustainable development. This compromises the ability of Barbados to invest in sustainable development initiatives to reduce the dependency. According to \cite{blechinger_barriers_2014}, Caribbean islands face several barriers for the development of renewable energy technologies, which can be clustered in technical, economic, political and social. Especially relevant as ranked by various stakeholders is the lack of a regulatory framework and legislation for private investors as well as the gap between policy targets and implementation measures. Caribbean islands have long been understudied in this regard \citep{shirley_renewable_2013}. Nonetheless, inter alia due to the absence of local fossil fuel resources, transportation costs and the lack of economies of scale, analyses of renewable energy potentials are particularly interesting for SIDS.

There are a number of studies analysing a 100~\% RES for developed countries, such as for Denmark within \cite{lund_energy_2009}. Looking at island energy systems, \cite{alves_road_2020} showed that the Azores can significantly increase their renewable energy penetration with lower costs compared to fossil fuel based systems. \cite{gioutsos_cost-optimal_2018} showed that for several islands across the globe the optimal systems' levelised costs occurred between a renewable penetration rate of 40~\% - 80~\%. Above this range, the high costs of storage, caused by over production, leads to curtailment of renewable energy sources, which is a cheaper option selected by the ESMs as opposed to presently available storage technologies. Most of the studies agree, that a major challenge in modelling 100~\% renewable energy systems on islands is the excess power production due to the variable wind resource, which results in expensive installed capacities \citep{child_scenarios_2017}.

Focusing on Caribbean SIDS, \cite{dominkovic_integrated_2018} used the PLEXOS model to determine the optimal share of renewable energy for the island of Aruba was 78.1~\%. At about half the size of Barbados, Aruba has also committed to a 100~\% RES with a total installed capacity of 230~MW, a peak demand of 125~MW and a renewable share of 15.4~\% in 2015 \citep{healey_energy_2020-1}.

\cite{watson_photurgen_2017} used Photurgen as an open access/source model and GIS information to optimise a hybrid solar-wind system on the island of Jamaica. \cite{chen_pathways_2020} uses DIgSILENT/Power Factory to examine the implications of a 100~\% RE on the Jamaican power grid by replacing spinning reserves from fossil fuel power plants with battery storage, to balance the effects of fluctuations in electricity generation from renewables. \cite{vazquez_energy_2018} conducted an economic analysis of the Cuban energy system using the LINDA spread-sheet based energy system model to examine various scenarios for a 100~\% RES to estimate the level of investment and possible dispatch.

\subsection{Barbados}
Scenario analyses have been conducted on possible futures for the Barbadian electricity system solely in studies on behalf of the Government of Barbados. A first investigation was carried out under the Sustainable Energy Framework (SEF 2010) for Barbados \citep{iadb_support_2010}. In 2010, a 100~\% RES was not yet an official policy target for the Government and was therefore not analysed. The study results led to the initial policy target of 29~\% of renewable energy in the electricity mix for Barbados in 2030 \citep{iadb_sustainable_2010}. However, the report did not publish modelling code, tools or methodologies. The Government also consulted the International Renewable Energy Agency (IRENA) for scenario analysis of the power generation sector, which recommended a share of 76~\% renewable energy instead of a 100~\% RES. The study did not consider pumped hydro-storage (PHS) as a viable storage option to support the 100~\% RES, but battery storage technologies \citep{irena_renewable_2019}. The viability of the 100~\% RE scenario depends on utilising a biomass potential of 54~MW, which would require 16 million tonnes of sugarcane per year from 20,000 hectares of land \citep{irena_barbados_2016}. However, as recent as 2016, only 7,000 hectares of arable land for sugarcane production were available \citep{lind_potential_2018}. A study conducted by \cite{hohmeyer_economic_2017} examined the possibility of a 100~\% RES using PHS to achieve a dispatch with lower levelised costs of electricity. All scenarios employed between 200 and 260~MW of wind and PV, as well as 11~MW of solid waste combustion. The scenarios varied only in the extent of biomass utilisation and technology for bio energy generation.

Within the Barbados National Energy Policy (BNEP) 2019, scenario analysis was also conducted to examine possible dispatch options. Although, a 100~\% RE system remains the goal for Barbados, the purpose of the scenario analysis was to examine possible dispatch options of a 76~\% RE system, centred on \cite{irena_barbados_2016}, using a multi-criteria approach based on environmental, economic and social considerations \citep{gob_barbados_2019}. \cite{irena_barbados_2016} is the only study to examine an optimised dispatch with renewables, conventional generators and battery storage using LEAP and OSeMOSYS. Table \ref{tab:overview_of_pre_studies} summarises key figures of the previously introduced scenario analyses.

\subsection{Scientific contribution}\label{sci_contribution}
Models of a 100~\% RES for Barbados exist, are, however, based on closed energy system models, which pose challenges associated with the inability to reproduce the outputs for external examination. Previous studies are also heavily depended on external aid, without which investment in most SIDS energy sectors would be non-existent \citep{niles_small_2013}. Donor agencies have the technical, legal and professional capacities to draft policies and review institutional structures. This may also lead to the development of energy policies as a prerequisite or condition to further access funds from the donor or loan agency. When using closed models as seen in the development of the SEF 2010 for Barbados, the findings are solely presented as final results, without scrutiny from third parties.

Open access research may be more beneficial for the Barbadian energy system by improving transparency, generating and fostering the re-usability of results as well as adding scientific value to discussions on carbon neutral energy systems. The greater openness offered by oemof \citep{hilpert_open_2018}, in the form of open source code and raw model results, can address the problem of external donor agencies and the possibility of biased results. As shown in \autoref{state_of_research}, none of the previous studies considered high shares of RE, the possibility of PHS nor a combination of multiple storage types. Additionally, the study at hand is the first to assess the possibility of electrifying one of the most relevant revenue sectors for Barbados, the cruise ship tourism sector. Analysing shore-to-ship renewable power can benefit the country and the society as a whole with lower GHG emissions as well as reduced air pollution levels and increased health standards. The investigation focuses on examining various possible scenarios for a cost-optimal integration of RE into the energy system, as well as analysing the possibility of a 100~\% RES. Furthermore, the presented open source model can be used to address similar research questions for other SIDS energy systems. Therefore, the presented model does not only contribute to the scientific debate of decarbonising energy systems to mitigate climate change, but can also mark an important step for capacity building and sustainable development in other SIDS through open, unbiased dialogue.

\section{Mathematical model}
To assess the future energy system, a bottom-up optimisation linear programming model is applied. The model has been implemented based on the model generator oemof-solph \citep{krien_oemofsolphmodel_2020} using the oemof-tabular interface \citep{hilpert_introducing_2021}, which are both part of the Open Energy Modelling Framework (oemof) \citep{hilpert_open_2018}. A similar model has been applied for the analysis of the Jordanian energy system \citep{hilpert_analysis_2020}.\\

In the following mathematical description, endogenous (input) variables are printed in bold to distinguish them from exogenous model variables. The model minimises total operational costs for the time horizon $T$ and annualised investment costs of units $u \in U$ as well as storage investment costs of all storages $s \in S$ for the Barbadian electricity system. The respective objective function is given below in \autoref{eq:objective}.

\begin{align}
    \text{min} : \overbrace{\sum_{t \in T} \sum_{u \in U}  c^{opex}_u  \textbf{p}_{u,t}}^{\text{operational cost}}  +  \overbrace{\sum_{u \in U} c^{capex,p}_u  \textbf{p}^{nom}_u}^{\text{power inv. cost}}   + \overbrace{\sum_{s \in S} c^{capex, e}_s  \textbf{e}^{nom}_s}^{\text{energy inv. cost}} \label{eq:objective}
\end{align}

The operational costs $c^{opex}_u$ are calculated based on the efficiency $\eta_u$ of a unit $u$ and its fuel cost $c^{fuel}_u$ according to \autoref{eq:opex}.
Annualised investment costs $c^{capex}$ are calculated based on the lifetime $n$, weighted cost of capital $wacc$ and the specific investment cost of a technology $capex_u$ as well as the fixed operation and maintenance cost $fom$ in \autoref{eq:capex}.

\begin{align}
    c^{opex}_u &= \frac{c^{fuel}_u +c^{var}_u}{\eta_u} \label{eq:opex} \\
    c^{capex}_u &= capex_u \cdot
            \frac{(\text{wacc} \cdot (1+\text{wacc})^n)}
            {((1 + \text{wacc})^n - 1)} \cdot (1 + fom) \label{eq:capex}
\end{align}

The demand must equal the sum of supply of all producing units as described in \autoref{eq:demand-constraint}. Note, that for the storage units, $p$ can also take negative values when the storage is charging. The total demand in every time step is composed of different loads such as households, electrical vehicles and cruise ships with their specific patterns and is assumed to be inelastic.

\begin{align}
     \sum_{u \in U} \textbf{p}_{u, t}  = \sum_{l \in L} d_{l, t} +  \textbf{p}^{excess}_t \qquad \forall t \in T
     \label{eq:demand-constraint}
\end{align}

For all investment units, the supply is limited by the installed nominal power \textbf{p}$_i^{nom}$ described in \autoref{eq:p-bounds}, which is bounded by a lower and upper investment limit as shown in \autoref{eq:power-potential}.

\begin{align}
    0 \leq \textbf{p}_{u, t} \leq \textbf{p}^{nom}_{u}  &\qquad \forall u \in U, t \in T
    \label{eq:p-bounds}\\
    \underline{p}_i \leq \textbf{p}^{nom}_u \leq \overline{p}_i &\qquad \forall u \in U
      \label{eq:power-potential}
\end{align}

The energy storage balance in \autoref{eq:storage-balance} is applied for all modelled storage types. The balance includes standing losses $\eta^{loss}$ as well as charge and discharge efficiencies $\eta^{in/out}$.

\begin{align}
    \textbf{e}_{s, t} = \textbf{e}_{s, t-1} \cdot \eta^{loss}_s - \frac{\textbf{p}^{out}_{s,t}}{\eta^{out}_{s}}   + \textbf{p}^{in}_{s,t} \cdot \eta^{in}_{s}  \qquad \forall s \in S, t \in T
    \label{eq:storage-balance}
\end{align}

Additionally, the power of the storage is limited by the optimised nominal power shown in \autoref{eq:storage-p-bounds}.

\begin{align}
       - \textbf{p}^{nom}_s \leq \textbf{p}_{s,t} \leq \textbf{p}^{nom}_{s} &\qquad \forall s \in S, t \in T
       \label{eq:storage-p-bounds}
\end{align}

For all volatile RE technologies, i.e. PV and wind, the power output is determined by \autoref{eq:re-power} where $c^{profile}_{v,t}$ is the time dependent normalised generation profile of the unit $v \in V$.

\begin{align}
       \textbf{p}_{v,t} = c^{profile}_{v,t} \textbf{p}^{nom}_v &\qquad \forall v \in V, t \in T
       \label{eq:re-power}
\end{align}

Analogous to \autoref{eq:p-bounds} and \ref{eq:power-potential}, the energy storage content and its maximum investment is bounded as shown in \autoref{eq:storage-e-bounds} and \ref{eq:energy-potential}.

\begin{align}
   e^{min}_{s} \cdot \textbf{e}^{nom}_{s}\leq  \textbf{e}_{s,t} \leq \textbf{e}^{nom}_{s} &\qquad \forall s \in S, t \in T
   \label{eq:storage-e-bounds} \\
   0 \leq \textbf{e}^{nom}_{s} \leq \overline{e}_s &\qquad \forall s \in S
   \label{eq:energy-potential}
\end{align}

The dispatchable renewable units $d \in D$ are modelled with a conversion process as described in Equation \ref{eq:conversion}.

\begin{align}
       \textbf{p}_{d,t} = \eta_{d} \cdot \textbf{h}_{d,t}  \qquad \forall d \in D, \forall t \in T
       \label{eq:conversion}
\end{align}

The conversion process allows to introduce the input of fuel $h$, which can then be bounded for a time horizon within \autoref{eq:fuel-max}. This equation allows to model (annual) resource limitations in biomass or waste.

\begin{align}
       \sum_{t \in T} \textbf{h}_{d,t} \leq \overline{h}_c \qquad \forall d \in D
       \label{eq:fuel-max}
\end{align}

To model RE penetration within the system by an exogenously defined RE share, an additional constraint is introduced. The renewable energy share is defined within \autoref{eq:RE-share} by the share of conventional technologies $c \in C$.

\begin{align}
    \sum_{t \in T} \sum_{c \in C}  \textbf{p}_{c,t} \leq (1-RE^{share}) \cdot  \sum_{l \in L} c^{amount}_{l}
    \label{eq:RE-share}
\end{align}

Finally, the excess supply within the model is limited by two equations. Equation \ref{eq:excess_power} limits the excess power in every time step, while Equation \ref{eq:excess_energy} limits the excess energy for the whole time horizon.

\begin{align}
    \textbf{p}^{excess}_t &\leq 0.1 \cdot \sum_{l in L} c^{amount}_l \cdot  c^{profile}_{l,t} \qquad \forall t \in T \label{eq:excess_power}\\
    \sum_{t \in T}  \textbf{p}^{excess}_t &\leq 0.1 \cdot \sum_{l \in L} c^{amount}_{l}
    \label{eq:excess_energy}
\end{align}
\\

\subsection{Scenario assumptions}
The analysis considers ten scenarios, of which the main parameters are summarised in \autoref{tab:study_summary}. All scenarios are modelled in a cost-optimal (without \autoref{eq:RE-share}) and a 100~\% renewable case, where \autoref{eq:RE-share} applies with a value of 1 for the $RE^{share}$ parameter.

Since all currently, as of 2020, installed conventional electricity generators will be retired by 2030 due to their age, a greenfield planning approach can be applied. The first scenario represents the status-quo (SQ) on the demand side and is primarily designed for the comparability of results with other studies and therefore does not consider electrification of sectors other than energy generation. The second scenario is used as a reference scenario (REF) for the remaining scenarios and includes the electrification of passenger transport vehicles and cruise ships.

The total future system demand for 2030 was set at 943~GWh, which is the current demand of 2019. The demand increased only marginally from 912~GWh in 2013 and, as stated in \cite{blp_integrated_2014}, is not expected to increase substantially due to demand side management and energy efficiency measures in the residential and commercial sector. The high demand scenario (HD), assumes, analogous to \cite{blp_integrated_2014}, an expected growth in residential, commercial and industrial demands between 2012 to 2030 of 1.2\% annually, which generates an annual system demand of 1,321.3~GWh for 2030.

The demand profiles for the electrification of the transport sector and the cruise ships are analysed as separate profiles to the annual system demand. All scenarios, except SQ and EVUC, use the same demand profiles for the electrification of sectors as well as the same base demand (expect HD) with varying dispatchable renewable generation, PHS and battery storage and costs to address uncertainties.

On the renewable supply side, wind, solar, biomass (bagasse) and waste are considered in all scenarios with varying capacities. Based on \cite{hohmeyer_economic_2017}, the annual potential of biomass and waste is limited in the REF scenario to 656~GWh\textsubscript{th} and 218~GWh\textsubscript{th} respectively (169~GWh\textsubscript{el} and 74~GWh\textsubscript{el}). The generation profiles for wind and solar are based on the \emph{Renewables.Ninja} project \citep{pfenninger_long-term_2016, staffell_using_2016}. The conventional units considered are low and medium speed diesel generators (lsce and msce) fired with heavy fuel oil (hfo). A combination of fuel efficient lsce and smaller msce is considered as a viable solution for Barbados, according to \citep{blp_integrated_2014}. The model and the scenario input data are publicly available on GitHub \citep{hilpert_oemof-barbados_2021}.

\begin{table}[!h]
\centering
\footnotesize
\caption{Overview of scenario assumptions including demand and technical parameters. All scenarios, except SQ, consist of base demand, electric vehicle demand and cruise demand as in the REF scenario - with variations as stated in parameters.}
\label{tab:study_summary}
\begin{tabular}{p{3cm}p{1cm}p{4.5cm}p{2cm}}
\toprule
Scenario    & Symbol    & Parameter & Value\\
\midrule
Status-quo              & SQ    & Base demand   & 943~GWh\\
Reference               & REF   & Base demand   & 943~GWh\\
                        &       & EV demand, controlled charging     & 265~GWh\\
                        &       & Cruise demand & 44.15~GWh \\
                        \midrule
High Demand             & HD    & Base demand +\,1.2\%/a & 1,321.3~GWh\\
Restricted Biomass      & RB    & Biomass potential -50\%   & 328~GWh$_{th}$ \\
                        &       & Waste potential -50\%     & 109~GWh$_{th}$  \\
No PHS & NPHS  & No PHS investment                   & - \\ \midrule
\multicolumn{4}{c}{\textbf{Cost variations}}\\ \midrule
Low oil price           & LOP   & Oil price -50\%           & 59.2 \$/kWh \\
Electric vehicle uc     & EVUC  & EV demand, uncontrolled charging & 265 Wh \\
Low RE costs    & LRC   & Long term wind costs   & 2900 \$/kW\\
                        &       & Long term PV-distributed costs & 2100 \$/kW \\
                        &       & Long term PV-utility costs     & 1500 \$/kW \\
Medium RE costs    & MRC   & Medium term wind costs   & 3335\$/kW\\
                        &       & Medium term PV-distributed costs & 3150 \$/kW \\
                        &       & Medium term PV-utility costs     & 2250 \$/kW \\
High bagasse cost       & HBC      & Higher bagasse investment costs  & 18400 \$/kW\\
\bottomrule
\end{tabular}
\end{table}

\subsubsection*{Demand profile}
The electricity demand in Barbados was modelled based on the assumptions of the Integrated Resource Plan \citep{blp_integrated_2014}. Although, the document has not been updated since 2014 it remains the primary source of information on generation and future demand of the Barbadian energy system. \cite{irena_barbados_2016}, \cite{hohmeyer_economic_2017} and \cite{gob_barbados_2019} were used to validate and compare the final demand in the target year 2030. The annual hourly load profile was simulated from a sample 7-day hourly demand curve from 2014, as outlined within \cite{hohmeyer_economic_2017}. The demand profiles for electric vehicles and shore-to-ship charging for cruise ships were created as separate demand profiles, as depicted in \autoref{fig:load-pattern}.

\subsubsection*{Cruise ship demand}
At the time of the present analysis, no information regarding the energy consumption nor the demand profile of cruise ships in Barbados were publicly available. However, \cite{hoyte_shore--ship_2016} has conducted an extensive study of the cruise industry demand in Barbados, which is used in this research as well as information from the local port authority \citep{bpi_port_2020}. Analysis of the port data shows, that cruise ships typically dock for a period of 5 to 20 hours, with 92~\% docking longer than 10 hours. About 50~\% of all recorded cruise arrivals (431 in 2018) docked between 10 and 12 hours, only 7.7~\% stayed less than 10 hours. The large majority of all ships arrived between 5:00 and 10:00 am (see \autoref{fig:arrival_and_stay}).
A 12 hour demand profile for the docking time of one generic ship was applied, using a peak demand of 12~MW, multiplied by the actual arrival data from 2018 \cite{bpi_port_2020}. Within the first two hours after docking with peak demand, the demand drops to low demand, increasing again to peak demand at the end of the docking time. This relates to on-board activity creating a maximum demand, which is reduced when passengers leave the ship for on-shore activities. After a certain amount of time, passengers return, increasing the demand.

In literature, there is a range of varying peak demand to be used in the assessment for shore power. \cite{wang_costs_2015} states, depended on the vessel type and length, a peak demand for cruise ships from 7.3~MW (\textless\,200m), 11~MW (\textgreater\,200m) and 20~MW (\textgreater\,300m). \cite{hoyte_shore--ship_2016} assumes a peak demand of 15~MW for all cruise ship types. The average length over all for all cruise ships docking in Barbados in 2018 is about 250 m \citep{bpi_port_2020}, which would relate to a demand of 11~MW, following \cite{wang_costs_2015}. However, assuming a higher peak demand ensures that the demand is not underestimated, as there are plans to expand port capacity, which would imply a future doubling of berthing capacity relative to the present.

The seasonal pattern in the annual demand from cruise ships is clearly visible in \autoref{fig:cruise_demand}.

\subsection*{Electric vehicle demand}
On Barbados, there were 94,100 registered vehicles as of 2016 \citep{irena_barbados_2016}. Just over 81~\% are passenger vehicles, followed by light and heavy goods vehicles (11.2~\%), private taxis and minibuses (3~\%) as well as rental cars (2.7~\%). Following \cite{irena_barbados_2016}, only the electrification of the largest share of vehicles, passenger transport, was considered. Within the model, in all scenarios but the SQ scenario, an electrification rate of 80~\% by 2030 was assumed, which is in-keeping with the goals of the BNEP 2019. Controlled charging is mapped in all scenarios but SQ and EVUC, where peak demand occurs around noon. The annual demand of 265.4~GWh as well as the daily load profile was modelled after \cite{irena_barbados_2016} and \cite{gay_small_2018}. As a comparison, a scenario with uncontrolled charging (EVUC) is set up, where the charging peak occurs around 6:00 pm.

The electrification scenarios cause a higher total demand and an altered aggregated demand pattern. Figure \ref{fig:load-pattern} shows the first week of 2030 with three different modelled load patterns as well as the aggregated demand with values of the REF scenario.

\begin{figure}[!h]
    \centering
    \includegraphics[width=\textwidth]{figures/load-profiles-input.pdf}
    \caption{Modelled load patterns of electricity demand, electric vehicles and cruise ships for one week (main figure) and the cruise ship daily average for a whole year (small figure upper right).}
    \label{fig:load-pattern}
\end{figure}

\begin{table}[!h]
\centering
\caption{Cost and technical data for supply units in the REF scenario with costs in BBD. wacc - weighted average cost of capital, $\eta$ - efficiency, fom - fixed operation and maintenance, vom - variable operation and maintenance. Values from \cite[p. 92]{blp_integrated_2014} for generation technologies and \cite{mongird_energy_2019} for storage units.)\\ $^*$Storage cost in include 100 \$/kW and 600 \$/kWh with a E/P ratio of four.}
\label{tab:tech_data}
\begin{tabular}{llp{1cm}p{1cm}p{1cm}p{1cm}p{1cm}p{1cm}}
\toprule
      &      &  capex (\$/kW) &  life \newline(a) &  wacc (-) &  $\eta$ \newline(\%) &  fom (\%) &  vom (\$/MWh) \\
Carrier & Technology &               &               &           &          &          &              \\
\midrule
wind & onshore &        3500 &            20 &      0.07 &    100.0 &      4.0 &            0 \\
solar & pv-distributed &        5400 &            20 &      0.07 &    100.0 &      1.0 &            0 \\
      & pv-utility &        3900 &            20 &      0.07 &    100.0 &      1.0 &            0 \\
lithium & battery &         2500$^{*}$ &            12 &      0.07 &     94.9 &      3.0 &            0 \\
hydro & phs &        5000 &            45 &      0.07 &     89.4 &      1.0 &            0 \\
hfo & lsce &        2853 &            30 &      0.07 &     46.4 &      4.0 &           12 \\
      & msce &        2344 &            25 &      0.07 &     43.9 &      7.0 &           18 \\
bagasse & st &        8000 &            25 &      0.07 &     25.3 &      3.6 &           15 \\
waste & ocgt &       18000 &            20 &      0.07 &     34.1 &      3.9 &           15 \\
\bottomrule
\end{tabular}
\end{table}

\newpage

\section{Results}

\subsection{Installed capacities and energy balance}
Figure \ref{fig:installed_capacities} depicts the installed capacities per supply technology. In all scenarios, independent of the cost-optimal or the 100~\% renewable energy (RE) case, RE sources are the substantial share of the overall installed capacity. Wind energy has the highest capacities ranging from around 168~MW in the LRC-scenario to 371~MW in the HD-100 scenario. Within the SQ scenario, 211~MW wind capacity compared to 269~MW in the REF scenario are necessary to cover the increased demand due to the electrification of passenger transport and cruise ships. Additionally, much higher conventional capacities are needed in the REF scenario (169~MW msce) compared to the SQ scenario (76~MW), as well as increased PHS (46~MW respective 18~MW). The maximum possible PV-utility potential of 80~MW is exploited in all scenarios, but SQ and SQ-100. Due to its investment cost, PV-distributed reaches high capacities only in the 100~\% scenarios, either due to cost reductions (MRC-100, LRC-100), higher demand (HD-100) or a restricted biomass potential (RB-100). Within the scenario of uncontrolled EV charging, no distributed PV is installed due to the higher costs of integrating PV electricity.

\begin{figure}[!h]
    \centering
    \includegraphics[width=\textwidth]{figures/installed_capacities.pdf}
    \caption{Installed capacities for all scenarios in the cost-optimal and 100\% RE setup.}
    \label{fig:installed_capacities}
\end{figure}

Despite their high investment costs, bagasse capacities around 30~MW can be found in all cost-optimal scenarios, except RB with 15~MW and no investment with a lower oil price (LOP) or higher investment cost of biomass (HBC). The reason are the significantly lower fuel costs of bagasse compared to heavy fuel oil, which has lower investment cost but high operational cost. Hence, for the LOP scenario, no bagasse investment is cost-optimal. In all 100~\% RE scenarios, bagasse capacity increases to values ranging from 60~MW in the RB-100 scenario to 96~MW in the HD-100 scenario. Installed capacities within SQ compared to REF are almost identical, with 30~MW (74~MW respective 84~MW in the 100~\% cases). The lower bagasse investment in the RB-100 scenario due to the restricted biomass potential is compensated by high PHS capacities. In all 100~\% scenarios, PHS capacity is above 95~MW (except \~37~MW in SQ). However, an installed capacity of 143~MW and 152~MW highlights the relevance of the PHS in the case of restricted biomass potential (RB-100) and uncontrolled EV charging (EVUC-100), respectively. Due to the large PHS capacity in the 100~\% scenarios, battery storage capacity is only required for up to 15~MW in cost-optimal cases. Lithium batteries also become important within the EVUC scenarios, to meet the shifted charging demand in the evening and PV peak during the day. Also, within the REF scenarios, batteries are applied (1~MW REF and 11.6~MW REF-100), whereas in the SQ scenarios, no battery capacities are necessary. If there is no PHS investment (NPHS), battery capacities of 56~MW in the cost-optimal and 101~MW need to be included. No conventional capacities exist in the 100~\% scenarios. In the cost-optimal scenarios values of conventional installed capacities are ranging from 76~MW in the SQ scenario to 271~MW in the LOP scenario. Investment in waste units can only be observed for 100~\% RE scenarios due to the high investment costs of 18.000 BBD/kW. Investment in lithium batteries is necessary in the NPHS scenarios, as well as, the EVUC scenarios, where the PV generation pattern cannot compensate for the increased demand from electric vehicles. The corresponding energy balance and RE-share is shown in Figure \ref{fig:energy}.

\begin{figure}[!ht]
    \centering
    \includegraphics[width=\textwidth]{figures/energy.pdf}
    \caption{Energy supply and demand balance (left axis) and renewable energy share (right axis) for all scenarios.}
    \label{fig:energy}
\end{figure}

The cost-efficient investment of renewable energy leads to high RE-shares above 80~\% in most cost-optimal scenarios (except for the LOP with 46~\% and HBC with 68~\%) with a maximum of around 93~\% in the LRC scenario. With the favourable capacity factor of wind and its therefore large installed capacities, the demand is covered mainly by wind, followed by conventional supply in the cost-optimal scenarios. Only with a reduction in PV cost (LRC, MRC), PV supplies the second largest share of electricity in the cost-optimal cases. Bagasse and waste supply only increase slightly from the cost-optimal to the 100~\% cases.

\subsection{Dispatchable Operation}
To analyse the system operation, PHS storage and bagasse dispatch is shown in Figure \ref{fig:operation} for the REF and REF-100 scenarios. The PHS is mainly charged in the afternoon, due to the high PV supply, shifting energy into the night and morning. A seasonal shift between the month with lower wind supply can be observed. While absolute PHS increases from about 46~MW in REF to over 124~MW in REF-100, the pattern remains the same. In contrast, both the maximum supply and the pattern of bagasse change from the cost-optimal REF to the 100\% REF-100 scenario. In the REF scenario, bagasse operates in full load during many hours of the year, while in the 100~\% scenario, bagasse operates as a peaking and back-up component in the system to supply electricity during periods of low RE supply (e.g. when wind drops and PV is not available). Bagasse is less utilised in the summer months with high PV and wind supply and lower demand due to the absence of cruise ships, but also at the beginning of the year with high wind supply.

\begin{figure}[!h]
    \centering
    \includegraphics[width=\textwidth]{figures/heatmap-REF.pdf}
    \caption{Heatmap for the operation of PHS (top) and bagasse (bottom) in the REF (left) and the REF-100 (right) scenario. }
    \label{fig:operation}
\end{figure}

The operation of the dispatchable components underlines the need for a highly flexible operation to incorporate and manage long periods of no production, as evident in the drop of wind electricity generation, and full-load production in other periods.

\subsection{Costs}
Investment costs play a crucial role, due to the Barbadian economic challenges, such as dept accumulation due to increasing and volatile prices of fossil fuels, limited sources of foreign exchange and a heavy dependence on external aid and donors. Figure \ref{fig:investment_cost} shows the annualised investment cost per technology for all scenarios. 100~\% RE systems typically require higher investment cost than the cost-optimal systems. Total annualised investment costs range from 126 Mio.\,BBD in the SQ to 204 Mio.\,BBD in the HBC (247 Mio.\,BBD in HD) in the cost-optimal cases and from 192 Mio.\,BBD (SQ) to 393 Mio.\,BBD (HBC-100) (410 Mio.\,BBD in HD-100) in the 100~\% RE scenarios. The costs range from 199 Mio.\,BBD to 293 Mio.\,BBD in the REF respective REF-100. It must be noted, that operational costs are significantly lower in the 100~\% RE systems due to the low or zero marginal cost of wind and PV, as well as lower cost for bagasse compared to heavy fuel oil, expect within HBC-100. While the share of energy provided from dispatchable renewable energies and storage is low, compared to the energy provided by volatile resources such as wind and photovoltaics, their share in the total investment costs is significantly high in the scenarios with 100~\% renewable energies. Lower RE costs, as in the LRC-100 and MRC-100 scenarios, lead to no investment in waste, whereas all other 100~\% scenarios rely on a waste investment. The increase in bagasse investment costs (HBC) leads to no investment in bagasse in the cost-optimal case, while in the HBC-100 scenario, higher investments are made in PV plants compared to the REF-100 scenario to compensate for the higher investment costs.

\begin{figure}[!h]
    \centering
    \includegraphics[width=\textwidth]{figures/investment_cost.pdf}
    \caption{Investment cost per technology for all scenarios in the cost-optimal and the 100~\% renewable energy setup.}
    \label{fig:investment_cost}
\end{figure}

One main driver for installed capacities and associated required capital is the demand, which is demonstrated by comparing the investment costs of the REF and the HD scenario. Another main driver are the costs required for flexibility, which is indicated by high investment costs for the HBC-100 scenario compared to the REF-100 scenario. The resulting systems' levelised cost of electricity (LCOE) show a moderate increase from cost-optimal to 100~\% RE systems. However, this increase is higher if renewable flexibility is expensive (HBC), restricted (RB) or the cost of fossil generation are low compared to renewable generation (LOP). The lowest LCOE for the cost-optimal case occurs in the LOP scenario (0.18~BBD/kWh), while the highest cost-optimal system LCOE can be identified for the HBC scenario with 0.25~BBD/kWh. In the 100\% RE scenarios, low LCOE of 0.18~BBD/kWh can be identified within the LRC scenario. In the reference scenario REF-100 costs are higher with 0.25~BBD/kWh but still significantly lower than for HBC-100 with 0.33~BBD/kWh.

\begin{figure}[!h]
    \centering
    \includegraphics[width=\textwidth]{figures/lcoe.pdf}
    \caption{System LCOE for all scenarios in the cost-optimal case (COPT) and the 100~\% renewable energy case (100RE) in BBD per kWh.}
    \label{fig:lcoe}
\end{figure}

\section{Discussion}
The results clearly indicate high potential shares of renewable energies in cost-optimal energy systems for 2030. The electrification of the cruise ship and transport sector is possible but requires additional investment capital, particularly for PHS and additional wind capacities. The high demand from electric vehicles reflected in the modelling results as well as the charging patterns pose a challenge for a future sustainable Barbadian energy system. If electric vehicle charging is uncontrolled, more storage is needed. This only leads to a slight increase in investment costs and LCOE. This underlines the role of demand response measures and energy policies to harness peak renewable energy generation. In the transport sector, a reduction in demand could be achieved by increasing the share of public transport and improving the infrastructure for (electric) bicycles to change the modal split. Additionally, an optimisation of the charging habits and the different effects controlled and uncontrolled charging have, needs to be further analysed and optimised, to counteract times with low renewable energy potential. This is highlighted within the modelling results, as higher RE shares are achieved within the REF scenario (controlled charging) compared to the EVUC scenario (uncontrolled charging). However, marginally higher investment costs are necessary within the REF scenario, respective the EVUC system.

The present study suggests priority on the expansion of the wind capacity as it has a higher system value than PV. Whereas the technology LCOE for wind and PV are similar, a system with high wind capacities can achieve lower overall system LCOE. Wind power therefore forms an important pillar for the future renewable energy system for Barbados, regardless the seasonal variations within the wind resource, which are challenging.

\subsection*{Costs}
Estimates showed, that in 2013, fuel costs alone made up 73~\% (0.413 BBD/kWh) of the total electricity production costs (0.566 BBD/kWh) in Barbados \citep{hohmeyer_economic_2017}. In 2015, the purchase of international oil cost the Barbadian economy 377 million BBD, resulting in high electricity costs passed to the public in the form of the Fuel Clause Adjustment \citep{hohmeyer_100_2015}. A higher renewable energy share does not necessarily result in higher electricity costs. With the likely future reduction in RE cost, as modelled in the LRC and MRC scenarios, a RE share of more than 90~\% is possible, while keeping system LCOE below 0.20 BBD/kWh (for LRC even in the 100~\% scenario). Reaching a share of 100~\% RE comes with only a slight increase in LCOE from 0.18 to 0.20 BBD/kWh (REF). However, these values do not reflect integration costs, such as grid and balancing costs or taxes, but solely system generation costs. This needs to be considered and analysed in further detail. Regardless, the respective required (annual) investment costs of the HD scenario are 47.6 Mio.\,BBD per year higher than in the REF scenario. These cost can be interpreted to be available for a 40~\% demand reduction. Although the LCOE may not differ largely between the HD and REF scenario, higher capital investment is required. As supported in previous studies, there is a sharp increase in investment costs as the energy system approaches a 100~\% RE.

\subsection*{Flexibility}
Lack of or expensive flexibility within an energy system can lead to significant problems, especially when demand increases, the flexibility potential is restricted. In Barbados, flexibility is provided by biomass (bagasse) and waste and will play a significant role for investment costs and LCOE in the future energy system. Further research is necessary to determine how much of the currently installed capacity might be used as flexible generation units. In addition, the use of biomass may be limited due to operational requirements in systems with high shares of RE.

\subsection*{Limitation of Study}
The results of this study have to be critically read in the light of the used method and model. Within the model supply units are aggregated and not represented as individual units. In addition, grid constraints and spinning reserves are not considered. Another important restriction of the model is the applied perfect-foresight approach, which particularly matters within the context of the specific Barbadian weather pattern. The drop in wind supply in autumn in combination with restricted biomass resources and storage capacities requires long-term planning of dispatchable power plant operation and storage management. While the perfect-foresight approach allows to optimise this operation for a whole year, it will be much more challenging in reality. The maximum installed capacities are constrained, due to meteorological and geographical conditions. The wind resource was capped at 472~MW in keeping with the recommendations of \cite{rogers_desktop_2017}. The solar resource is constrained at 234~MW at the residential level. Without studies to support the expansion of utility scale solar on the island, this potential was constrained to 80~MW for all scenarios. Considering utility-scale PV is the cheapest renewable resource and was always selected by the model and used at maximum potential, it is vital to verify the assumed potential.

The assumptions made, may lead to rather optimistic results in terms of capacities and costs. The costs for the integration of renewable energies, such as grid expansion and back-up capacities for stable system operation, must be added to the costs presented in this study. While integration costs are highly context specific literature values suggest that these costs can range of 35 to 50~\% of the total generation costs \cite{hirth_integration_2015}. The challenges of long-term operational planning under resource constraints in 100~\% RE systems also need to be considered.

\subsection*{Value of open source}
The boundaries and specifications posed within the context of Barbados, such as load profiles and possible resource capacities are key factors when analysing electricity systems. This information, however, is not always available to the public nor to scientists. Additionally, future economic and political developments can change fundamentally within a short period of time altering assumptions taken within the model. The applied Open Energy Modelling Framework offers the possibility to flexibly adjust input data and thus quickly and transparently adapt to changing circumstances without reducing the traceability of results.

\subsection*{Shore-to-ship power}
The study describes shore-to-ship demand based on the annual arrival of cruises ships and varies with the tourist season over the course of the year. The cruise ship demand contributes significantly to the total energy demand of Barbados. The cruise ship demand pattern is almost complementary to the wind generation profile, which further supports the suitability of this resource for the Barbadian energy system. However, more research examining how renewable energy sources can optimally meet the daily cruise ship demand through e.g. scheduled docking times by the system operator, would be beneficial.

\section{Conclusion}
Due to good renewable energy resources and future cost developments, a cost-optimal system design in Barbados already features a share of over 80~\% renewable energy, assuming a future reduction in RE costs with current oil prices. Even with increased demand due the electrification of cruise ships and passenger transport, a renewable energy share of over 80~\% is achieved, with only slightly increased system LCOE (0.22 BBD/kWh respective 0.20 BBD/kWh). Particularly the energy potentials of waste and bagasse and the flexible operation of these systems need to be validated to ensure a stable 100~\% RE-system for the future. In the case of Barbados, imported bio-diesel for backup may be required due to the specific wind and solar pattern. Nonetheless, PHS can lower the costs of a 100~\% renewable set-up, additionally reducing the consumption of resources needed for batteries. The value of pumped hydro is only slightly affected by higher costs of renewable energy sources, lower oil prices or a demand reduction. Therefore, when aiming for 100~\% RE, the results indicate that PHS is a no-regret option for the Barbadian energy systems design.
An open source energy system model as introduced here for the island of Barbados marks an important step towards decarbonising SIDS. By using an open source model, the problems of external donor agencies and the possibility of biased results, especially in the context of Small Island Developing States, are addressed. The study additionally underlines the feasibility of RE systems, even with an increasing demand including the electrification of sectors other than electricity generation.
\clearpage

\small\textbf{Data availability}\\
\footnotesize
The model is available at \url{https://github.com/znes/oemof-barbados/releases/tag/v0.2}.
\\

\small\textbf{CRediT authorship contribution statement}\\
\footnotesize
A. Harewood: Conceptualization, Resources, Data curation, Validation, Formal analysis, Investigation, Supervision, Project administration, Writing - original draft. F. Dettner: Conceptualization, Resources, Data curation, Validation, Formal analysis, Investigation, Methodology, Writing – original draft, Writing – review \& editing. S. Hilpert: Conceptualization, Software, Methodology, Investigation, Visualization, Writing – original draft.
\\

\small\textbf{Declaration of competing interest}\\
\footnotesize
The authors declare no known conflict of interest, financial or otherwise.
\\

\small\textbf{Acknowledgements}\\
\footnotesize
André Harewood and therefore his work is supported by the National Development Scholarship Scheme Barbados by the Ministry of Education, Technological and Vocational Training.

\clearpage

redpajama_set_name: RedPajamaArXiv


He's a retired boxer who finds a baby on his doorstep with the note "She's yours."
Except she isn't. She can't be. Or maybe she can.
What's a guy to do but ask his single-mom next door neighbor for help?
Retired boxer Grayson Hollister is trying his best to stay off the booze and run a successful martial arts center when he finds a baby on his doorstep. Uncertain who she or the mother might be, he enlists his next-door neighbor to help him find the answers.
Kara McGarrity runs the town's food pantry and soup kitchen. A single mom who's seen her share of abuse, the last thing she wants is to get involved with someone with a past like Grayson's. But with a baby's future at stake, her maternal instincts kick in.
Though both Grayson and Kara are determined to put the baby's interests before their own, it's only a matter of time before adrenaline and attraction take over. But the moment they let down their guard, a local threat they never suspected becomes a danger to them all.
Book 2: COUNTDOWN: ETHAN Releasing simultaneously! Look for pre-order links soon.
Book 3: COUNTDOWN: STEELE Releasing simultaneously! Look for pre-order links soon.


Fortunately, eye muscle surgery recovery does not involve feeling much pain though at the same time your eyes will start to feel very scratchy. In addition, the eyes will turn red in color and they will water quite a bit as well. You might also experience some amount of hemorrhage that occurs below a certain membrane that is situated above the whites of your eyes though this hemorrhaging settles down within 2 to 3 weeks.
During eye muscle surgery recovery you can expect that there may be some discoloration to the eye that reminds you of a bruise and in addition you have to reckon with having the membranes thickening above the eye and this means that you will simply have to wait for a few weeks for the condition to clear.
During eye muscle surgery recovery period you will also notice some swelling as well as discharge though there is nothing to worry on account of the swelling which is actually minor and which occurs a couple of days following the surgery after which you will be able to open your eyes once more as the swelling will have disappeared.
Driving is of course not permitted during the eye muscle surgery recovery period which means that you will need someone to drive you about. Taking aspirin as well as non-steroidal inflammatory agents for two to three days following eye muscle surgery is not recommended. Furthermore, during eye muscle surgery recovery period you need to discuss which medications are safe to take though only your surgeon or doctor will be able to advise you in this regard.
Typically, there is no one fixed eye muscle surgery recovery period and it varies according to individual conditions and here again you will need to be advised by your surgeon regarding how long you need to wait before performing normal routine activities. Also, during eye muscle surgery recovery you need to avoid getting your eyes wet for at least three if not four days and swimming of course is not recommended.
For some, there is also risk that during the eye muscle surgery recovery period that they will have a mild attack of double vision with young children experiencing this for a little longer than is the case of adults.
As for adult eye muscle surgery it is believed that about one in thousand adults will need to undergo this kind of surgery which is fewer than in the case of children (one in 640). In regard to eye muscle surgery recovery it is also recommended that you take an appointment with your surgery for about eight weeks after the surgery to see how well or poorly the eyes has stabilized.


Every now and then, DWO committee volunteers host an extravagant gala event whereas it gets decorated to making it an authentic experience to its fullest imagination with a full course cuisine, music, door prizes, silent auction, and awards.
To name a few that were hosted in the past were the Hollywood Red Carpet Gala, The Wild Wild West, and Kentucky Derby Gala.
Each time DWO hosts the gala, the numbers of attendees of DWO volunteers, loved ones, and friends kept growing!
It is an event not to be missed the next time!
DWO Volunteers mastering their skill at Western dancing!
Former DWO Board Members in their best outfilts!


Employer-provided coverage is the most common method by which Americans get their health insurance, covering about 170 million workers and dependents annually.1 All companies that employ 50 or more full-time equivalent employees (FTEs) will be required to provide qualifying health benefits to their full-time workers under the Affordable Care Act (ACA) by 2016. Employees that average 30 hours or more of work in a week during a month are considered to be full-time under the ACA.
The employer mandate and the individual mandate for consumers were both scheduled to go into effect in January 2014, but the employer mandate portion of the ACA has been delayed one year for employers with 100 FTEs and two years for employers with 50-99 FTEs.


The appealing photograph below, is section of 2019 Audi Jeep New Release written piece which is grouped within Wallpaper, audi 2019 jeep, 2019 audi suvs, and published at September 2nd, 2018 19:18:14 PM by admin.
Here is main recommendation on audi 2019 jeep. We have the prime sources for audi 2019 jeep. Check it out for yourself! You can find 2019 Audi Jeep Release Date guide and read the latest 2019 Audi Jeep New Release in here.


We are thankful for this festive door hanger and so much more! Decorate your door with this festive door hanger this Thanksgiving. Email for customization options: add streamers or a monogram. This item is hand painted on screen. Its imperfections are what make it unique.


text:
15 Luxury Vacations That Are Surprisingly Affordable
These luxury vacations offer incredible experiences and five-star amenities without breaking the bank.
By Isis Briones
Editor's Note: Travel might be complicated right now, but use our inspirational trip ideas to plan ahead for your next bucket list adventure. Hotels were chosen based on late summer/early fall 2020 dates, and rates are subject to change.
Planning a vacation is never an easy task, especially when it's time to talk about budget. But hey, luxury vacations aren't always crazy expensive. We think it's time for you to take the luxury trip of a lifetime without breaking the bank, so we've found 15 vacation ideas that will leave you in awe of the trip and the price.
1. Stay in a French Castle for $82
Credit: Courtesy of Airbnb
While some Airbnb listings — like Kylie Jenner's $50-million rental in Turks and Caicos — are only for the very wealthy, the hospitality service also has hidden gems for the more budget-conscious traveler. Jet off to France and live out your royal dreams by staying in a three-bedroom castle with a pool for as little as $82/night.
2. Dance All Night in Fiji
All-inclusive tickets to Your Paradise start at $2,199 AUD (which comes out to around $1,540 USD) and include a flight from Sydney, Melbourne, or Brisbane along with a five-night stay at the breath-taking Mamanuca Islands, main land and sea transfers, and of course, the chance to see an incredible lineup of artists.
3. Find Your Joie De Vivre in Paris for under $200 a Night
Credit: Courtesy of Paris Perfect
Experience the fabulous life of a French local with Paris Perfect. The vacation rental agency provides accommodation options at some of the most unreal apartments in the "City of Lights" with rates beginning at under $200 a night. Since you'll have a kitchen, you could even save more by picking up groceries nearby and cooking.
4. Go Glamping for Under $100 a Night
Stylish glamping stays to private chalets are available at a range of price points, with several options under $100 per night.
5. Fly Private at Economy Prices
Credit: Courtesy of JetSuiteX
A ticket through JetSuiteX gives you access to a private terminal, where you can go from parking to takeoff in 15 minutes. No more being stressed out about getting to the airport early, waiting in long lines, or squeezing into a coach seat. The catch: Flights are only available between major West Coast cities.
6. A Cheap and Chic Colombian Getaway
Credit: Courtesy of Conrad Hotels & Resorts
Colombia's port city of Cartagena seems to be on everyone's travel bucket list these days. Make that dream trip a reality with an affordable booking at the Conrad Cartagena. You can find nightly room prices from $140, and the hotel's stunning Caribbean views alone are worth it. Of course, the five-star hotel has other high-quality amenities including a luxurious spa and salon, an 18-hole golf course, beachfront swimming pools, a number of elegant restaurants and so much more.
7. Dar es Salaam, Not Zanzibar
Credit: Courtesy of Wyndham Hotels & Resorts
Tourists — especially newlyweds — are quick to head to Zanzibar's resorts. While there's no denying the quality of these expensive seaside accommodations, don't forget that it's possible to have a similar luxury beach experience on the Tanzanian mainland for a much more affordable price. The Ramada by Wyndham in Dar es Salaam — with rooms from $149 a night — is located along the shores of Jangwani beach. It's a budget-friendly way to enjoy the waves of the Indian ocean, while taking in the nearby city center. The hotel also offers airport shuttles and late checkout.
8. Live It up in New York City
Credit: Auseklis/Getty Images
Instead of squeezing yourself into Manhattan for an average, over-priced hotel room, venture out into Brooklyn for equally trendy neighborhoods — here's looking at you, Bushwick and Williamsburg — for much more affordable rates.
9. A Taste of Thailand
Credit: Rachata Wannaphahul/EyeEm/Getty Images
Opt for a stress-free, grand getaway to Southeast Asia for 10 days for $1799 per person on this Friendly Planet vacation across Thailand. With roundtrip airfare, hotel accommodations, and visits to some of the country's most historic attractions such as the the UNESCO World Heritage Site Ayutthaya, don't pass up this deal.
10. Stay at a Five-star Resort on the Amalfi Coast
Credit: Courtesy of NH Collection Grand Hotel Convento di Amalfi/Preferred Hotels
This five-star beauty is elegant and historic. What used to be a 13th-century monastery has been converted into an Amalfi Coast hotel with some of the most spectacular views around — and almost all the rooms look out to sea. Even though it's high up a cliff, it's only a five-minute walk to the harbor and city center. There's also a majestic Catholic church at the hotel for those looking to tie the knot.
11. Private Pool Views
Credit: Courtesy of Hotel Las Brisas Acapulco
A stay at one of these oceanside suites Hotel Las Brisas in Acapulco, Mexico is your chance to truly treat yourself without breaking the bank. For under $200 a night, you can book a casita with a private pool overlooking incredible views.
12. Visit Tulum for $150 a Night
Credit: Moses Berkson
Stunning accommodations and private beach access make Ahau Tulum worth visiting. Depending on the time of year, you could book a stay in the charming Bali Huts for less than $150 per night.
13. Relax in Cambodia
Credit: hansgertbroeder/Getty Images
Breathe easy with a stay at this intimate, 36-room, five-star hotel alongside the Siem Reap River in Cambodia. All of the rooms at Jaya House Riverpark have either balcony views or direct garden or pool access, and it's just a short ride to Angkor Wat. Rooms start at around $200 a night depending on the season.
14. Paradise in Punta Cana
Credit: Courtesy of Hilton
For under $200, enjoy Hilton La Romana, an all-inclusive, adults-only resort in Punta Cana, Dominican Republic. The new space offers numerous luxe amenities like unlimited 24-hour room service, gourmet dining options, oceanfront bars, nightly entertainment, and more all built into the price of the room.
15. Fall in Love With Franschhoek
Credit: pilesasmiles/Getty Images
The sunny vineyards of Franschhoek in South Africa are a wine-lover's paradise, and planning a trip for the low season allows for hotel rates under $200 a night. Check out the Franschhoek Boutique Hotel, which is situated a few steps from one of the trolley stops that conveniently takes you on an array of routes to different wineries in the area.

redpajama_set_name: RedPajamaCommonCrawl


This thesis is a comprehensive look at the qualities of precious metals and their attributes on investing in Nordic stock markets. The thesis concentrates to study whether precious metals serve as hedges or safe havens in Nordic stock markets during the study period from January 1999 to January 2015. The other main purpose of the study is to test what gain an investor in Nordic markets can achieve by introducing precious metals as a part of an investment portfolio.
Commodities are in growing demand as real assets for variety of purposes they serve and as investment assets for investors they have new opportunities to gain profits during different real economy and financial market situations. Precious metals stand out from other commodities in being a group of metals with unique qualities on investing. The main precious metals are a group of four metals: gold, silver, platinum and palladium, which all have an international currency code. Besides being approved as currency, they have a distinct quality of being both investment and industrial assets. For an investor precious metals' quality of having very low correlation with equity indexes can be a very valuable quality. Precious metals have varying correlations with each other, thus an effectively diversificated investment portfolio can be built by investing only in precious metals.
With a regression model including 1%, 2.5% and 5% lower quantiles of the worst stock returns in the Nordic stock markets, each precious metal is regressed. The results show that gold acts as a hedge and safe haven in all of the Nordic stock markets. Silver also acts as a hedge in half and safe haven in all of the Nordic stock markets. In the portfolio analysis the relative efficiency improvement of a Nordic stock portfolio is analyzed by using different weights of each precious metal in the stock portfolio during the study period. There is a significant improvement for the risk adjusted return of each Nordic stock market gained by investing part of the portfolio to a precious metal or in equal weight to all of the precious metals.


text:
You are here: Home Page > Arts & Humanities > Media Studies > Television > The OA
120 Pages | 20 black and white illustrations
David Sweeney
Auteur Publishing in partnership with Liverpool University Press
The first full-length critical appraisal of a ground-breaking TV show
Considers the varied influences on the show - from David Lynch, particularly Twin Peaks (1990-2017), Mulholland Drive (2001) and Inland Empire (2006), and comparable texts such as the Netflix Originals series Sense8 (2015-18) and Maniac (2018); and the writings of Jorge Luis Borges and Philip K Dick
Also viewed through the lens of media and social theory, including the work of Jean Baudrillard, Steven Shaviro, Jodi Dean, Mark Fisher and Shoshana Zuboff
Created by the team of Brit Marling and Zal Batmanglij, and starring Marling in the role of Prairie Johnston, the Netflix Originals series The OA (2016-19) is a generically ambiguous vehicle for exploring a variety of themes, chief among them identity, belief and the nature and construction of reality. Prairie claims that she has learned the secret of inter-dimensional travel after a near-death experience and subsequent imprisonment at the hands of a deranged scientist obsessed with that phenomenon - but is she a potentially unreliable narrator, a sincere one or, finally, a metafictional character playing a version of herself in a fictional drama?
This Constellation discusses The OA's thematic concerns in the context of the creators' earlier collaborations and in terms of influences on it, such as the work of David Lynch, particularly the TV series Twin Peaks (1990-2017) and the films Mulholland Drive (2001) and Inland Empire (2006), and comparable texts such as the Netflix Originals series Sense8 (2015-18) and Maniac (2018); the writings of Jorge Luis Borges and Philip K Dick. The discussion will be supported by sources from the fields of media and social theory, including the work of Jean Baudrillard, Steven Shaviro, Jodi Dean, Mark Fisher and Shoshana Zuboff. Negative criticisms of The OA will also be addressed, such as accusations of superficiality, which will be considered alongside the themes of deception, manipulation and artificiality identifiable in The OA specifically, and in Marling and Batmanglij's wider oeuvre.
Dr David Sweeney is a lecturer in The Glasgow School of Art's department of Design History and Theory where he specialises in popular culture. His particular interests include science fiction and horror texts.
Nick Riddle
The Ghost in the Image
Cecilia Sayad
Joshua Grimm
Television at Work
Kit Hughes
Screening the Police
Noah Tsika
Transmitted Wounds
Amit Pinchevski
Christian McCrea
The Shape of Motion
Jordan Schonig
Jon Towlson
Broadway in the Box
Kelly Kessler
Totally Truffaut
Anne Gillain
Regulating Big Tech
Martin Moore and Damian Tambini
Arts & Humanities > Media Studies > Television
Arts & Humanities > Media Studies > Film
Arts & Humanities > Media Studies
Arts & Humanities > Society & Culture > Cultural Studies


Items sold by Walmart. If you need to return or exchange an item you can send it back at no cost or take it to your neighborhood store. Cancel your subscription any time. Want to get your items fast without the pricey shipping fees? Am I able to set up sub-accounts within my Shipping Pass subscription for family and friends?
DESIGN: Baby raincoat Children's Long Sleeve Solid Coat Outwear Hoodies Totes Unisex Rain Poncho. by totes. $ - $ $ 13 $ 20 00 Prime. FREE Shipping on eligible orders. Some colors are Prime eligible. 4 out of 5 stars Product Features Children's Rain Poncho by Totes Isotoner. edit Tell us where you are located and we can tell you what's available. Shop for childs raincoat online at Target. Free shipping on purchases over $35 and save 5% every day with your Target REDcard.


text:
Designing dictatorship
David Crowley
Iron Fists: Branding the 20th-century Totalitarian State
By Steven Heller
Designed by Adam Michaels of Project Projects
Phaidon Press
£45
I went to Tate Modern a few years ago with a Polish friend who had grown up during the last years of Communism in eastern Europe. Looking at a Soviet poster from around 1930 featuring a beaming Stalin, he issued a loud and irritated snort. 'I bet they'd never put Hitler up there.'
It seemed to him – to paraphrase Orwell – that in the minds of Tate curators 'all dictators are equal but some dictators are more equal than others'. Iron Fists, Steven Heller's new book, puts Stalin, Mussolini and Mao in the dock alongside Hitler. Its premise is that the commercial practice of branding today shares the same characteristics as the design and management
of images in the major dictatorships of the twentieth century. Heller's approach is to pull out common themes in each society, such as the production of national symbols or the cults woven around the figure of the leader.
The branding analogy does not, however, quite add up to an argument in the sense that Heller does not draw significant conclusions from his homology. How should our understanding of the effects of branding be changed knowing that the leadership in the Third Reich were pioneers in the field? How does a rhetorical question like 'What were the Führer, Il Duce, Comrade Lenin and Chairman Mao but a kind of ideological trade character?' add to our understanding of their brutal rule?
This book is built on two concepts. The first one, 'totalitarianism', is explicit in the subtitle: the other, Modernism, is offered as its antithesis. Most – if not all – contemporary historians working on regimes such as the Soviet Union have given up on the first term. In stressing the impotence of individuals in the face of the total power of the state or a leader, this relic of the Cold War does little to sharpen our understanding of resistance or the subtle ways in which power is distributed throughout society. Heller's use of it is a little strange, as Heller is a liberal with a genuine sense of commitment to freedom: it runs through his writing. And in Iron Fists, he expresses strongly his disdain for regimes that turned to design
to promote distorted values and camouflage brutality.
For Heller, Modernism is a force for good in the world. This argument falters when he runs up against a 'totalitarian' image that seems to display the hallmarks of Modernist style, for example, a 1932 National Socialist election poster, which, in its stark minimalism and use of sans serif typography, 'could easily be confused with Modernist design'. What stops it being so is not very clear. In fact, after the first, and best, section of the book on Nazi Germany, the Modernist / totalitarian distinction on which Heller bases his study evaporates. Almost half of his discussion of the Soviet Union, for instance, reviews the familiar output of Modernists such as El Lissitzky and Gustav Klutsis, a victim of the Great Purges. The question of the relationship of Modernism to power is not a new one. Much of the best recent writing – on art, architecture and design in Nazi Germany and in the Soviet Union under Stalin – has tried to grapple with it. In the most dramatic examination of this relationship, writers such as Peter Fritzsche, on Hitler's Germany, and Boris Groys, on Stalin's Soviet Union, have claimed that far from extinguishing avant-gardism, these dictatorships embraced the totalising impulse of Modernism, which, in its most ambitious forms, took the wholesale transformation of life as its aim. This means conceiving of Modernism as much more than style.
Heller writes with pace and verve, which makes Iron Fists a readable book. It does, however, contain errors of fact, loose expressions and contradictions that diminish its appeal. What makes this book worth picking up are the illustrations: Heller and his picture researcher, Jeff Roth, have gathered a really remarkable set of images, many of which have not been reproduced before. Some are truly chilling: pretty porcelain figurines were made in Mao's China during the late 1960s and early 1970s, for instance, depicting acts of denunciation, a very public and sometimes violent form of humiliation licensed by the Great Proletarian Revolution. Strangely enough, one reading of this kind of object is that, in use, it offered a form of self-defence: to design or
even just to display this kind of object was to shield oneself from attack. But this kind of reflection points to a more complicated and ultimately messy picture of 'totalitarian' design than Iron Fists offers.


Pushing back the school start time by 25 minutes will not have substantial benefits for students. In fact, it may cause inconveniences. The main issues with a later start time include the effects on sports and extracurricular activities, scheduling conflicts, and production of unwarranted costs.
Taking traveling time into consideration, sports may either cut into the school day or run later more frequently, causing students to miss in-class work or to have less time to participate in other activities outside of school. For example, in my case, tennis may run later than 6 PM, which will cut into marching band rehearsals that run from 6 PM to 9 PM and produce a number of problems for me. My future 10th period teacher will be frustrated with my numerous absences, and I will be even more stressed from making up all the work on my own time, which I will not have much of. Overall, students may not be happy as they will be forced to squeeze academic, athletic, and extracurricular priorities into fewer available hours. Look through this page for details on best projector under $200.
Furthermore, parents who have already adapted to the original school start time now have to adjust their schedules accordingly. Parents who normally drop their kids off before heading to work can no longer do so, and these children must take the bus. Due to the change, some kids will receive the same amount of sleep even with the later start time simply because their parents can no longer drive them to school. This outcome would completely undermine the purpose of the later start time.
Additionally, pushing back the start time proves costly. For the later start time to be successful, more buses will be needed for transportation throughout the district, and purchasing new buses will come at a hefty expense that could be directed toward more important causes, such as programs or clubs that receive little to no funding. While an 8 AM start time may seem to be a small step in the right direction, the drawbacks will be much greater than the benefits.


text:
Q: In asp.net what is the difference between ValidationProperty and ValidationPropertyAttribute metadata attribute? Simple Question, but I can't seem to find the answer.
What is the difference between the ValidationProperty and ValidationPropertyAttribute metadata attributes?

A: Nothing, attributes can be used with their full name or without the Attibute suffix. The comiler will automatically add Attribute if it can't find an attribute with the short name.

Note   By convention, all attribute names end with the word "Attribute" to distinguish them from other items in the .NET Framework. However, you do not need to specify the attribute suffix when using attributes in code. For example, you can specify HelpAttribute as follows:
  [Help("http://localhost/MyClassInfo")] // [Help] == [HelpAttribute]

From
http://msdn.microsoft.com/en-us/library/aa288454(v=vs.71).aspx#vcwlkattributestutorialanchor2

A: There is no difference. You can use both [ValidationProperty] and [ValidationPropertyAttribute]. Ending 'Attribute' is optional. The same is for all other system attributes.

redpajama_set_name: RedPajamaStackExchange


Large projects are no problem for our 1000-foot bulk RG59/U white braided coaxial cable. This cable is conveniently spooled inside a pullbox that allows for easy storage and dispensing. Our cable's 20 AWG, solid core copper conductor provides excellent data transfer for crystal-clear connections. Both ends of the cable are bare-ended, which means that it is ready for any project that you may need it for. It also features a 95 percent bare copper braid and polyethylene (PE) foam insulation. Trust CableWholesale for quality - this product comes with a lifetime warranty, as well as live online support.


Here is the step by step process for Gauhati University online Form Fill Up 2018-19.
Gauhati University after a massive waiting now again begun to receive online form fill up for upcoming TDC BA, BCom and BSc Examination.
Gauhati University 1st Sem Form Fill Up all candidates or students can fill up the exam form by following below given steps.
The Last Date of Gauhati University online Form Fill Up is 25th September 2018.
Note: Students must carefully fill and submit the Examination Form, as once submitted, the Examination Form would not be available for modification to the students.
In case of any error or correction in the Examination Form, the student would then have to refer to their respective college.
Gauhati University already completed online registration process of students and they already provided and they already provided a Login ID and Password.
Now students are required to login to the portal of Gauhati University BA/ BCom/ BSc 1st, 3rd, 5th Semester Form Fill Up with already provided User ID and Password. Visit below given link to login.
Note: User can also view the Examination Form Start and end dates for the Under Graduate (U.G) degrees by clicking on "Examination Form of Under -Graduate (U.G) degrees (2018-19)" link.
'Registration No.'. By default, Registration No is displayed.
via entering his/her 'Application No /Registration No. ', 'Date of Birth' , and 'Captcha'.
Step 6: Select an option from "Medium of Exam" & "Belong to NC (Non Collegiate Category)?" field.
If student has opted for B.A (General) degree, he/she needs to select 4 papers.
Student has opted for B.A (Major) degree, he/she needs to select 5 papers.
A student has opted for B.Com (General) degree, he/she needs to select 4 papers.
When student has opted for B.Com (Major) degree, he/she needs to select 5 papers.
Step 8: Once all the mandatory fields are filled and subjects are selected, click on "Get Papers" button.
Step 9: Click on "Reset Subject" button, when student wants to selects subjects all over again, prior to clicking on "Get Papers" button.
Step 10: After clicking on "Get Papers" button, Under "List of all Courses", previously selected papers are displayed for Gauhati University Form Fill Up.
Step 11: If user wishes to change the previously selected papers after clicking on "Get Papers" button, he/she can do so, by clicking on "*Click here For Change Subject Group" link.
Pop up message is displayed, click on "OK" button to submit.
Step 14: Click on "Preview" tab, for the user to verify all the details under 'Online Examination Form', 'Candidate Registration Details', 'Candidate's Course Details Preview', 'Candidate's Identification Details', 'Correspondence Address Details', 'Permanent Address Details' & 'Photo and Signature' sections.
Post details verification by the student , check the Declaration check – box (I hereby declare___ ) and click on "Accept and Generate Challan".
This is the complete process for Gauhati University Online form fill up.
Just follow the above steps to do the Gauhati University 1st Sem Exam Form Fill Up without any error.


A study has shown that garlic, white onion, and purple onion help protect against Type 2 diabetes and high blood pressure, which may be attributed to their strong antioxidant properties. The study, which was published in the Journal of Dietary Supplements, examined the effect of aqueous extracts of garlic, white onion, and purple onion on key enzymes linked with Type 2 diabetes and hypertension.
Garlic, white onion, and purple onion, which are commonly used as ingredients for soups and traditional delicacies, naturally contain antioxidants, such as polyphenols.
A team of researchers from the Federal University of Technology in Nigeria aimed to determine the inhibitory effect of aqueous extracts of garlic, white onion, and purple onion on key enzymes linked with Type 2 diabetes and hypertension, such as angiotensin-converting enzyme (ACE), alpha-amylase, and alpha-glucosidase activity in vitro.
The research team also evaluated their antioxidant properties through different antioxidant assays.
Based on the results, the aqueous extracts of garlic, purple onion, and white onion all exhibited inhibitory effects against ACE, alpha-amylase, and alpha-glucosidase activity in a dose-dependent manner (0–4 mg/ml).
Purple onion had the greatest inhibitory effect on ACE among white onion and purple onion.
White onion displayed the highest inhibitory effect on alpha-amylase among garlic and purple onion.
The aqueous extracts also exhibited free radical-scavenging activity and prevented lipid peroxidation in the pancreas and heart.
These findings suggest that garlic, white onion, and purple onion exhibit antidiabetic and antihypertensive properties due to their inhibitory effect on key enzymes linked with diabetes and hypertension and their powerful antioxidant properties.
To read more studies on foods that prevent hypertension and Type 2 diabetes, visit SuperFoods.news.


text:
Give to History
Lucy Chester
Associate Professor of History and International Affairs
University of Colorado at Boulder
Past Courses (please email for syllabi)
HIST 4349: Decolonization of the British Empire (Fall 2015)
IAFS 4500: Culture and Conflict in South Asia (Fall 2015)
HIST 3020: Historical Thinking and Writing (Spring 2015)
HIST 4339: Borderlands of Empire (Fall 2014)
IAFS 4500: Post-Cold War South Asia (Fall 2014)
IAFS 1000: Global Issues and International Affairs (Fall 2009)
IAFS 1000: Global Issues and International Affairs
(Honors section, Fall 2012)
IAFS/JWST 3650: History of the Arab-Israeli Conflict (Spring 2013)
IAFS 4500: Post-Cold War South Asia (Spring 2009)
HIST 3133: The Decolonization of the British Empire (Fall 2009)
HIST 4020 (Capstone): Imperialism and Colonialism: The British Empire in India, 1760-1947
(Spring 2013, team-taught with Prof. Susan Kent)
HIST 4053: Britain and the British Empire (Fall 2003)
HIST 4538: History of Modern India (Spring 2004)
HIST 5339 (Graduate component of HIST 4339, Fall 2012)
HIST 5349: Graduate component of HIST 5349 (Fall 2010)
HIST 6020: Modern Empires (Fall 2006)
HIST 6628: Readings in South Asian History (Spring 2009)
Networks of Decolonization: Britain's Withdrawal from South Asia and Palestine (working title)
"On Creating a 'Palestinian Pakistan,'" Sh'ma: A Journal of Jewish Responsibility (May 2011) 17-18
Borders and Conflict in South Asia: The Radcliffe Boundary Commission and the Partition of Punjab (Manchester UP, 2009)
"Factors Impeding the Effectiveness of Partition in South Asia and the Palestine Mandate," in Order, Conflict, and Violence, ed. Stathis Kalyvas, Ian Shapiro, and Tarek Masoud (Cambridge, UK: Cambridge UP, 2008): 75-96
"Boundary Commissions as Tools to Safeguard British Interests at the End of Empire," Journal of Historical Geography 34:3 (July 2008) 494-515
"Imperial Cartography in the End of Empire: Map Use During the 1947 Partition of South Asia," in La cartografia europea tra primo Rinascimento e fine dell'Illuminismo, eds. D.R. Curto, A. Cattaneo, and A.F. Almeida (Firenze: L.S. Olschki, 2003)
"The 1947 Partition: Drawing the Indo-Pakistani Boundary," American Diplomacy 7:1 (Feb 2002)
"The Mapping of Empire: French and British Cartographies of India in the Late Eighteenth Century," Portuguese Studies 16 (October 2000)
"Mapping Imperial Expansion: Colonial Cartography in North America and South Asia," The Portolan 45 (Fall 1999)
Selected Presentations
"'Nothing to Fear:' Links between Nationalists in South Asia and Palestine," British Studies Seminar, University of Texas at Austin (Invited presentation) (Feb 2008)
"Policymakers and Nationalists: Biography and Empire in India and Palestine," Decolonization Roundtable, Annual Meeting of the American Historical Association, Washington, DC (Jan 2008)
"'The Caliphate Bogey:' Pan-Islamic Identities in South Asia and the Palestine Mandate," Anglo-American Conference of Historians, Institute of Historical Research, London, UK (Jul 2007)
"'Little Commissions Set up Lesser Commissions:' Comparing the Role of Boundary Commissions in British India and the Palestine Mandate," International Boundaries Research Unit conference, Durham, UK (April 2006)
"Indian Opinion and British Bayonets in the End of the Palestine Mandate," Humboldt Foundation Conference on Power and Principle, St. John's College, Cambridge University (May 2005)
"(Not) Resolving Religious Conflict in South Asia and the Middle East: British Attempts to Impose Order," International Conference on Order, Conflict, and Violence, Yale University, New Haven, CT (April-May 2004)
"Competing Cartographies: Indian and Pakistani Maps of Kashmir," International Conference on the History of Cartography, Portland, ME (June 2003)
"Mass Violence and the Indo-Pakistani Boundary in the 1947 Partition of Punjab," Sawyer Seminar on Mass Violence and Genocide, Center for Advanced Study in the Behavioral Sciences, Stanford University, Palo Alto, CA (December 2002)
"Drawing the Indo-Pakistani Boundary," International Security Program, Belfer Center for Science and International Affairs, Kennedy School of Government, Harvard University, Cambridge, MA (October 2002)
"The Radcliffe Commission: Cartography, Carnage, and the Roots of Indo-Pakistani Conflict" at Foreign Service Institute, Washington, DC (Invited presentation) (January 2002)
"Imperial Cartography in the End of Empire" at conference on "The Making of European Cartography," Florence, Italy (Invited presentation) (December 2001)
Selected Outreach
A Brief History of Darfur (STAND, Midwest Regional Conference, Jan 2007)
Hellems, Room 204
history@colorado.edu
Give to CU History