Hi,
We have had the PassivEnergy system installed for over two years and really like it. I also install the system so have very good knowledge of what it can and can't do. If you would like to discuss it, or if I can just help answer some questions for you, please drop me an email with a phone number and a good time and which to reach you, and I will give you a call. I am based near Oxford by the way.
Kind regards
Julian