Grid Connect (or Grid Tie) inverters are DC to AC inverters which are able to export the ac power which they produce to the grid.
The basic idea is that you produce DC via solar panels (PV) or a wind turbine and then you push this through the inverter and out to the grid. For this electricity you produce you will be paid by the energy company, based upon a contract which has previously been signed.
In order to do this in the UK you need for the inverter to comply with (amongst other regualtions) the G83 regulations.
At Simply Power Supply, we do not offer these units for sale on-line as we feel that a conversation aboutt he units are required before purchase, however, if you do require a G83 Approved Inverter then please contact us to discuss your requirement.