How do solar PV panels work?
A solar PV system captures the sun’s energy and uses it to generate electricity. The system will continue to work even in cloudy conditions. Not only could you save money by generating your own electricity, you could also earn money from the Government's Feed-In Tariff.
Technical information made simple
Solar PV panels are made up of solar cells. Each cell is made from one or two layers of semi-conducting material, typically silicon, covered by non-reflective glass. Here’s how a typical system works:
- The light shines on the cell and this creates an electric field across the layers, causing electricity to flow.
- The electricity flows through a cable and is collected at a central point generally under the panels and located in your roof space.
- The electricity produced is Direct Current (DC) and needs to be converted to Alternate Current (AC) by an inverter which is fitted as part of the system. This is AC current is then used in your home to power your lights and appliances.
- If you don’t use all the electricity that you have generated, it will be fed into the National Grid automatically. It is estimated that you will export 50-75% of the electricity you generate. If the system can’t provide you with enough electricity, i.e. at night, the Grid will automatically supply you as it does now, for which you will be charged.
The stronger the sunshine, the more electricity you can produce, but PV cells don’t need direct sunlight to work – you can still generate some electricity on a cloudy day.
The strength of a PV cell is measured in kilowatt peak (kWp). That’s the amount of energy the cell generates in full sunlight. This rating will determine the amount of electricity that you can produce. Typical domestic units are 3 or 4 kWp.
- Will solar PV give me electricity during mains power cuts?
- For the safety of electrical workmen, standard solar PV systems are shut off during power cuts. You can request a system that automatically disconnects your home from the grid during a power cut and provides power from the panels and a battery back up in your home during power cuts.
- What is the difference between monocrystalline and polycrystalline PV panels?
- Firstly, they look different - polycrystalline wafer has a dark blue colour, whereas monocrystalline wafer is black. Monocrystalline panels tend to be slightly more expensive and efficient than polycrystalline panels,
- Can I heat water with solar PV panels?
- Whilst PV panels do not directly heat water (this is what solar thermal panels do) they do produce electricity that can be used to do anything that you want to - even export it back to the grid for an extra payment. This electricity can be used to heat water if you have an immersion water heater.
- Will solar PV panels affect my home's rateable value?
- Council tax is based on the 1991 values and the government shelved plans to revalue all houses a few years ago, so currently, no. It is likely that there will be a revaluation in the not so distant future. When they do, the value of the solar panels will be included in the valuation, but the rating could also account for your home's the Energy Performance Certificate (EPC) which should reduce tax as you would have a lower EPC score.
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