Whenever your panels are producing more electricity than your home is using, it will flow back into the national grid for other homes to use. The Government Feed in Tariffs(FiTs) pay you an extra 3 pence per kWh for electricity you ‘export’. See our Example FiT Calculation.
According to Government sources an average 3/4 bedroom house consumes 4,000 – 5,000 units of electricity (kWh) a year. Check your last few bills or call your electricity supplier to find out how much you consume. The size of solar system you install depends on how much electricity you use, how much sunshine you receive, the size of your roof, and how much you’re willing to invest. The roof space available and budget often influences the size of system you buy and therefore the amount of electricity you can generate.
No. The system is connected to the national grid. In the night, when the cells are not generating energy, electricity is ‘imported’ from your usual supply in the normal way. Any excess electricity generated during the day, for example when you are at work, is sold back to the utility company.
Batteries are required if you specifically want an ‘off-grid’ solution or if your property is not connected to the grid so that power produced during the day can be stored for use in the evening. Batteries add significant costs to a solar system so are normally only installed in specific circumstances.
Domestic PV systems that are grid connected will automatically shut down. The inverter needs grid power to start up and operate so if there’s a power cut it won’t work. This is a safety measure designed to stop electricity leaking on to the national grid and to protect individuals who may be working to restore the power supply.
Surprisingly, this is not too much of a problem! It is light rather than heat that creates electricity although more electricity is produced in the summer months as the days are longer. Solar panels are actually happy in cold climates and for example on a sunny (but cold) day in January it can produce the same amount of electricity per sunlight hours as in July.
Yes. Solar panel efficiency has increased to the extent that it is now a viable option even in cloudy climates. It’s important to remember that solar power depends on the intensity of light, not necessarily direct sunlight. So, even when it’s overcast, your solar panels will be producing clean electricity to help power your home.
Solar panels consist of PV cells. Each cell is made from one or two layers of semiconducting material, usually silicon. When light energy shines on the cell it creates an electric field across the layers. The sunlight that hits the photovoltaic cells produces direct current (DC) electricity, which is fed into an inverter. The inverter converts the DC electricity to alternating current (AC), for use in the home. When the PV system produces more power than is needed it is exported to the grid national.
NO! Solar panels convert solar energy into electricity rather than create it. It’s changed from solar into electrical energy.
A kW is a thousand watts and a unit of power. A kWh is the amount of work done, or energy used, when a kW of power works for one hour.
A kWp is the kilowatt ‘peak’ output of a system, i.e. it’s maximum kW output. This is a test carried out under ‘Standard Test Conditions’ (STC) for panels across all manufacturers to ensure that the values listed are capable of comparison.