A top of the range 4 kW solar panel system could cost you somewhere between £16,000 and £22,000 depending on the make. Most 4 kW systems will actually be just under 4 kW in order to be eligible for the Feed-in Tariff (FiTS) rate of 43.3p per kWh. The best type of panel to go for would be a hybrid system which combines crystalline with amorphous PV and which generates heat as well as electricity. The Sanyo HIT system is the most popular and therefore probably the best hybrid you can buy.
Outside the hybrid’s 4 kW systems consist of the usual monocrystalline panels. You can get kits which you can install yourself and these are generally much cheaper, for example the Trueshopping 4 kW system costs £5,424. It comes with a 25 year warranty on output and consists of 16 panels and are claimed to be 15% efficient. They also have bypass diode technology which the company claims to help compensate for the drop in power in shady locations.
PVSolarUk offer a system which includes a set of 22 Sharp 180 watt monocrystalline modules with MPPT technology to optimize the energy generated. The company offer three payment options: purchase of the system outright, a payment plan through Barclays or free panels presumably through FiTS.
To get some idea of what a 4 kW system will do for you, PV Fit installed a system for a customer in Lancashire earlier this year. The system is now attracting a 14% annual return from FiTS on top of their initial investment and the income/savings over 25 years will be around £44,508. This particular system uses Caymax solar panels and a Nedap inverter.
One thing to be aware of is that District Network Operators (DNO’s) are starting to restrict the amount of power generated by solar PV systems without a special application. This is because DNO’s are having to work harder to balance the grid as solar PV becomes more popular. Installers now have to submit a Stage 2 application to the authority if they wish to install a system of 3.7 kW or above. However, this shouldn’t be of too much concern since according to YouGen a 4 kW system in the UK hardly ever generates 4 kW.