I realize this is not a new technology, but I would like to get the opinions and comments of others who may have worked on these systems or seen them.

What kind of problems have you seen or heard of?

Is the UK firm the only one selling these now? I did find a website from the UK for these but it has not been updated in almost 4-5 years! That made me wonder if these were still being sold or if the website is waiting to expire by neglect.

My understanding is the original firm was sold to a branch of an electric utility, which was then discontinued until a license was sold to a firm in the UK (the one mentioned in the website as Hy|Save UK.)

No detail is too small to mention.

Thank you for your comments and thoughts.