Stoop, be careful about the meter running backwards, that is illegal under the 'Feed in Tariff' scheme. The company should have either fitted an "Import / Export" meter or have arranged for the utility company to fit such a meter which will show how much has been generated (for which your installer will get 41p per kwh) and how much has been exported (for which they get a further 3p per Kwh) and how much has been imported from the grid for which you need to pay for. With your meter running backwards, you are getting free electric and the amount of electric you have actually used is being reduced and they are getting both the generation and export tariff. Your benefit in this scheme is only the free electric that you use and not to have your meter run backwards and lower your quarterly payment. Think of it as if you went over to Calis for 3 months and did not use any of the free electric from the panels. Your installer would get the generation tariff and your meter would run backwards so the electric company would owe you a big refund as your meter would read several hundred Kwh hours lower than the previous reading.
You might find that the Utility provider turns up and fits a meter, but be careful, some have been caught out and my friend who had the 4Kw system fitted showed me the form he had to fill in to register for the FIT which clearly asks the question, "does the meter run backwards when the PV is generating" he had to tell the truth as there is no way he would not be found out and EON were out in days to fit the new meter.