The micro-generation certification scheme (MCS) is run by the BRE (building research establishment) – apologies for the acronyms. The BRE is a government quango type of organisation which run by private organisations which is responsible for setting standards such as building regulations.
The MCS website is not the easiest to navigate, but on it you can find information on installers who have been accredited by the MCS, if the installer you chose to engage for your renewables is not on the list you may not be able to claim any of the subsidies and grants such as the Feed in Tariffs and Renewable Heat Incentive (RHI) which is going to be launched in April 2011. As well as making sure your installers are accredited it is also important to make sure the equipment they install has also been tried and tested and most importantly certificated by MCS.
There are several directories listing MCS installers but these may be just for people who have paid to advertise on these sites. There is only one place you can check definitively and that is the MCS website (follow the link below). If you are unsure ask your installer to show you their MCS certificate.