A 3kW solar panel system costs around £9,000 to buy and install. If you want to add a battery to this system, it’ll push the price up by about £2,000, for an overall cost of £11,000.
A 3 kW solar panel system won’t usually be able to power a complete off-grid setup, but it will still help you reduce the amount of electricity you use from the grid. You could go off-grid with a battery system by combining it with more than just solar panels – for example, you could add a small wind turbine to your setup.
A 3kW solar panel system is enough for your household if it approximately matches your annual electricity consumption. But you should always consider getting as large a solar panel system as your roof allows, if you can afford to.
The real cost of an off-grid solar power system varies depending on application but some ballpark figures may help you decide which is suitable for your needs. A 4.4kw power supply, 10kwh AGM battery bank, 4.4kw of solar, 8kw generator suitable for a 3 bedroom property costs in the region of £16,500.
If each solar panel has a power rating of around 350 watts there will be between eight and nine solar panels in a 3 kW system. You could even end up having fewer than this if you opt for monocrystalline solar panels.
On average, the roof area required for a 3kw solar panel system is around 12m - 17m². With a typical solar panel being 1m x 1.7m, a 3-kilowatt system of 6-8 solar panels would take up that much roof space, depending mainly on the wattage per panel and how the system is tilted.