Solar energy is abundant and sustainable. However, using solar energy to power an electrical grid may offer certain challenges.
For example, photovoltaic cells generally produce a maximum power at a particular voltage and current that depends on the properties of the cell and the amount of illumination. Away from this maximum power point, the conversion efficiency of the cell drops.
A utility-scale power plant may comprise such cells numbering in the thousands, deployed across square kilometers. Given this large scale configuration, it may be difficult to operate an entire plant at peak efficiency.
In addition, the output from photovoltaic cells is typically processed to produce an alternating current to output onto the electrical power grid. This can be difficult to manage with such a large number of discrete PV cells.
Finally, a solar power plant must operate under a range of non-ideal conditions. Examples of non-ideal conditions include a lack of full sunlight, and possible outages on an electrical power grid.
Accordingly, embodiments of the present invention relate to a cost-optimized architecture for a photovoltaic power plant that can operate at or near its maximum production efficiency. Embodiments of the present invention may continue to function under adverse conditions, such as grid outages and lack of full sunlight.
The series connection of various power sources, such as photovoltaic panels and cells, chemical batteries, fuel cells, thermo-electric devices, and the like is often desirable to increase output voltage. However, such arrangements often result in sub-optimal performance including lower power efficiency, lower lifetime, etc. because of differences between the characteristics of the various power sources, including efficiency, history, aging, temperature, temperature gradients, and illumination.
There is need in the art for better devices and methods for increasing the efficiency of such power systems.