Free solar panels a good idea for Northern Ireland homeowners?
The solar energy market in Northern Ireland appears to be taking off - the number of installations this year is three times what it was in 2012 according to figures from Ofgem.
This popularity is driven by energy prices going up and the price of some renewable technologies coming down.
Many of the solar installations have been in the domestic market where homeowners are attempting to reduce their bills in the longer term.
Buying an average domestic solar installation costs between £4,000 to £9,000 and it should pay for itself in about five to eight years.
But that significant upfront cost is not affordable to everyone and this is where free solar comes in.
Some companies offer to provide the installation and maintenance of the panels free of charge to the person who owns the property.
The homeowner will also be able to use the power generated, but the company that installs the panels will get the green subsidies that are called NIROCs (Northern Ireland Renewable Obligation Certificates) and any income generated through exporting power to the grid.
The agreement to rent the roof of a property lasts 20 years, so it is a long-term commitment.
If an individual installs the system at their own costs they have no long-term contract and they benefit financially from both reduced bills and the previously mentioned green subsidies.
Amber Green Energy is one of the biggest green energy providers in Northern Ireland and it's "not a big fan" of free panels.
Company chairman Neil O'Brien said free solar is not the best option for consumers.
"For us, to have someone else taking the benefits of free solar was really them eating your lunch; we felt it didn't suit the market," he said.
"If you want to sell or re-mortgage your home, that all comes with conditions because someone else has a claim to your rooftop."
Companies in favour of free solar say it can reduce the bills of people who could not afford to pay the upfront costs.
All maintenance is also taken care of in the free solar model.
But free solar could have an impact on selling homes or re-mortgaging because the Council of Mortgage Lenders (CML) has yet to issue specific guidance for Northern Ireland.
Until they do, banks could be reluctant to accept the lease agreements which give the installer a stake in the property.
Paul O'Brien Solar Installations is one of three companies in Northern Ireland which offer the free panels.
Company director Richard Love said it was important the CML publish advice for Northern Ireland soon.
"When the original free solar model was introduced in England and Wales in 2010, the CML looked at the different lease arrangements that were available and they released guidance which helped mortgage lenders be comfortable with those lease arrangements," he said.
"We want the CML to give the same assurance to mortgage lenders over here."
Most benefit will be derived from free solar by those who are at home or use power during the day. Any electricity used after dusk, when the panels are not generating power, will be paid for as normal by the homeowner.
Richard Love said people should change how they consume electricity.
"Your consumption habits can be changed dramatically from the installation so perhaps you can use such things as timers, perhaps you can look at staggering your washing machine or tumble dryers or dishwashers to go on at separate times during the daytime to make the most of the system," he said.
Patrick Thompson from the Energy Saving Trust said whether the system was owned or free there could still be savings.
"We reckon if you are in the house, using your equipment wisely, you could save between £100 and £300 a year with the 'rent a roof' (free solar) schemes," he said.
"If you were to do it yourself and pay for the panels you are looking at a saving of £500 to £700."
Consent of homeowner
Amber Green Energy draws attention to legislation unique to Northern Ireland called the Business Tenancies Order, which it suggests gives the solar installers the right to renew the lease at the end of the 20-year term without the consent of the homeowner.
But Mr Love, who is also chair of the Northern Ireland Solar Trade Association, said while that might be true in legislation, all three companies who are offering the free panels specify in their lease agreement that they will withdraw at the end of the term.
If roof maintenance is required during the 20 years of the free solar lease agreement, the homeowner will most likely have to meet the cost of removing the panels and having them replaced.
They could also be penalised for the loss of earnings while the panels were off and not generating power.
The solar industry in Northern Ireland is divided on what is best for consumers, but all agree it's important that homeowners know exactly what they are getting into.