Solar PV

 

What is Photovoltaic?

Photovoltaic is derived from two Greek words meaning light and electricity. Photovoltaic (PV) is a method of generating electrical power by converting the Sun’s solar radiation in direct current (DC) electricity using semiconductors known commonly as solar panels or PV modules.

What is a PV system?

The main components are the PV panels grouped together known as a ‘PV Array’ which is mounted on a frame, an inverter for transforming the DC electricity into alternating current (A/C), isolation switches for safety, a generation meter for measuring the amount of electricity generated and wiring.

How Solar PV systems work

How Solar Works

  1. The sun gives off light at all times, even on cloudy days
  2. PV cells on the panels turn the light into DC electricity
  3. The current flows into a Solar PV inverter, which converts it to AC electricity
  4. The current then goes through a generation meter and then into your consumer unit
  5. Your system will automatically use the free electricity you’re generating, then switch back to the grid as needed (i.e. when the sun doesn’t shine)
  6. Any electricity you don’t use is exported to the grid for others to use.

 

Solar Radiation

We view solar radiation as daylight and it is this that powers solar photovoltaic panels. However not all locations receive the same amount or concentration of solar radiation, think the strength of the sun in Scotland vs. Spain. This is the same in the UK; some locations receive more irradiation than others. According to PVGIS, European Commission software to estimate energy production from PV panels, the difference in the amount of electricity produced from a 4kWp system on a south facing 30 degree pitched roof in South West of England will generate about 3000 kWh/year. Depending on the current feed-in tariff you will be remunerated for feeding electricity into the public grid.

 

These calculations take into account the total irradiation received over the course of the year under different conditions. Where direct solar radiation is not blocked by clouds we experience it as sunshine. Where it is blocked by clouds or reflects off other objects, we experience this as diffused light. Diffused light will produce less power than unblocked light, because it has a lower concentration of solar radiation.

 

Electricity Generation

Depending on the size of your system, you’ll be paid the following rates for units of electricity generated on your property, regardless of whether you use it or not. Rates are linked to RPI and are guaranteed by the government for the next 20 years.