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Energy generation - Photovoltaic Cells
A photovoltaic (PV) cell is a electronic device that converts solar energy into electricity.
The (very) basic process is:
- Photons in sunlight hit the cell and are absorbed by the semiconducting materials (usually silicon) from which the cell is made.
- These photons collide with atoms in the cell and in doing so electrons are loosened.
- The electrons flow through the material and produce electricity.
PV cells are bundled together and through some very clever technology the low voltage electricity generated by the cells is converted to a higher voltage for use in appliances.
PV cells are able to utilise both direct light and indirect sunlight and so, contrary to popular myth are effective even under grey overcast skies.
There are then three options of what to do with the generated electricity:
- Use it to power electrical appliances!
- Store it locally - ‘batteries required’.
- Export it to the national grid - removing the need for battery storage.
You can read more on these options - energy storage options
Pros and Cons
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- A typical domestic installation in the UK will save around 1.2 tonnes of carbon dioxide per year
- No emissions of CO2 so renewable and sustainable
- No moving parts therefore minimal maintenance
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- Require a open roof (within 90 degrees of South) that is able to support the substantial weight of the system
- High cost - currently around £10,000 for a typical domestic installation in the UK
References:
http://www.energysavingtrust.org.uk/Generate-your-own-energy/Types-of-renewables/Solar-electricity