I had solar panels installed by Abacus Renewable Energy in June 2010. The shape of our roof limited the number of panels to 9 but we have an uniterrupted south facing aspect and have generated 900KWh in the first 6 months giving a return of £400. In addition our consumption has fallen such that our energy supploer has just reduced our monthly direct debit to £24 from £41 12 months ago. We found Stuart Houghton from Abacus extremely knowledgeable and efficient in his approach to and execution of the installation and would be pleased to recommend him for future installations.
We own our house in Dorset and have been intending to install PV panels for some time. I had been trying to obtain a grant but this required us to install cavity wall insulation and deeper loft insulation. I have sever reservations about filling our wall cavities as the house is at a high point on the South Western edge of Dorchester and is lashed by heavy rain from that direction. This could create damp internal walls if there was a problem in the wall cavity. I decided to go ahead because I felt that this was my contribution to generating energy from a "limitless" source.
Discuss your plans with several installers and assess their understanding of the installation.
If you are given estimates of the power taht you will gfenerate, and consequent cash returns, scrutinise the calculations.