There are many reasons for wanting to generate renewable energy.Photovoltaic (PV) electricty is one source of renewable energy:
Use it to power air source heat pumps for carbon zero air conditioning when its too hot.
Putting PV panels on the roof, especially in a sunny country like Spain, seems like a good idea. However at the moment the government is enforcing a what has become known as the sun tax. This idea is so stupid it can’t last. A coalition govenernment would probably repeal it and even if the Partido Popular wins a majority the government after that will have to repeal it.
Some of our clients are installing to “first fix” so that when the tax is lifted they can simply install the panels and they are in business.
Happily solar hot water is standard, easy to maintain and efficient.
In terms of PV there are roof mounted panels and integrated solar metal roofing. The latter is only appropriate for new builds and major renovations.
Amorphous silicon is probably the best kind of photovoltaic cell to go for. Compared with the alternative, crystalline cells, they have lower embodied energy, are thinner, and work better in overcast conditions.
Look out for guarantees for efficiency performance as the cells age for example they work to 92% efficiency after 10years.
There are design considerations that your architect will need to take into account. These are available from your supplier.
The cell generates DC electricity that is converted, by means of an inverter, into AC electricity that can be used to run domestic appliances.
A distribution system can feed this into the immediate needs of your home first. If its not sufficient top up from the grid. Surplus is exported to the grid and earns you credits from your supplier: not in Spain though.
Author: John Wolfendale
Bio: John is a founder of Eco Vida Homes and is passionate about bringing modern design and construction practices to Spain. He believes a home which is warm in winter and cool in summer is largely a matter of design and selective use of materials. He is British and a Chartered Surveyor with over 23 years experience living and working in Spain.