Solar PV


How It Works?

Solar PV panels use the sun to generate electricity. This is DC (direct current) electricity which needs to be converted to AC (alternating current) by an inverter which is usually placed within the loft of the house.
The AC electricity is then connected to the consumer unit of the house. During the night the house will take electricity from the National Grid and during the day the house will use a combination of the generated “solar PV” electricity and from the National Grid. This operation is done automatically. Electricity Bills are reduced due to offsetting the electricity which is use from the Grid.

If the house does not use this Solar PV or “green” electricity then it is fed back to the National Grid automatically. Today some energy companies will purchase this electricity at around the 10p per kWh (kilowatt hour) depending on the tariff rate you are on. However, in April 2010 Government legislation will come into force where energy companies will buy back this electricity at about two to three times amount shown. Solar PV will then not only make environmental sense (CO2 emissions around 1 to 1.5 tonnes /year) but economic sense as well (the return on investment will be reduced).

In Europe, these “feed in tariffs” have been introduced for a number of years especially in Germany where the number of Solar PV systems has increased dramatically in the domestic market with subsequent reduction in cost.

What Is The Typical Energy Usage?

The average electricity consumption of a UK household is around 4,700 kWh (kilowatts hours) per year. To understand what a kWh is, a good way is to look at kilowatts hours in a different way, like everyday human activities. A kWh of electricity means:

  • 1200 electric shaves
  • Drying your hair 15 times
  • Listening to 15 CD’s
  • Using a small refrigerator for 24 hours
  • Microwaving 20 meals
  • 4 evenings of light with 60W incandescent lamps

In the UK for every kWp of solar PV installed, it generates on average 850 kWh or units of electricity per annum.

There are five main factors that will impact how much energy a solar PV system will generate:

  1. The total size of the PV array.
  2. The latitude of the location.
  3. Which direction the PV panels face; ideal position is a southerly direction.
  4. What slope the panels are mounted on.
  5. Anything which shades the panels.

Do I Need Planning Permission?

Planning permission is not usually required as its falls under “permitted development”. However if you live in a conservation area or in a listed building it be worth checking with your local authority.

What Is The Installation Process?

The installation of a solar PV system is straight forward with the right supplier/installer who understands the project management process of a solar PV installation.
PTS supply Solar Photovoltaic Systems by Grant Efficient Heating Solutions.

Click “calc by system price” to see how much you save ∨


Solar PV calculator provided courtesy of Solar Guide.