Sustainable Tring
Community-led action to inspire sustainable living in and around Tring, Hertfordshire
How solar panels work!
Solar cells comprise thin sheets of silicon (found abundantly in sand and rocks) with electrical contacts on both sides, sandwiched between a sheet of glass and a polymer back sheet. A panel is an assembly of these cells contained in an aluminium frame.
Through the ‘photovoltaic effect’, silicon PV cells in the panels capture sunlight and the energy from this light knocks electrons loose from atoms, creating a voltage and a direct current across the silicon sheets.
This is then converted, by an inverter, to alternating current for use in homes and industry.
High power generation
Modern panels of about 1.7 x 1.0 metres can generate over 400 watts. On a sunny summer’s day 10 panels can easily generate 20 kwh. A typical system in the UK will generate around 850 kWh annually for every 1 kW of panels installed.
Long lasting
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25 to 35 years with a gradual loss of efficiency over their life.
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Warranties often cover 80% output at 25 years.
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Modern types of panel can degrade more slowly and last 40 years.
Good for most building types & situations
Solar panels can be installed in a wide range of places such as:
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Rooftop solar panels on homes and other buildings in towns and cities.
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Arrays of panels on large roofs of schools, churches, supermarkets, factories, warehouses, carports and facades.
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Large, countryside solar farms that can support local biodiversity by providing an undisturbed habitat for bees, butterflies and nesting birds. In hot weather they can provide shade for animals, as well as year-round grazing areas.
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In large arrays over rivers or canals where they reduce evaporation losses in hot weather.
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Vertically along the sides of highways.
Easy to install
See Big Solar Co-op ‘Solar fact sheets’ on suitability of roof shapes and coverings.
A few planning restrictions
Placing solar panels on the roof of a house or flat, or of a building within its grounds, is considered in most cases ‘permitted development’, meaning that in general there is no need to seek planning permission. The following limits must be met:
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On a pitched roof, panels should not be installed above the highest part of the roof (excluding the chimney) and should project no more than 200mm from the roof slope or wall surface.
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On a flat roof the highest part of the solar PV equipment cannot be more than 600mm higher than the highest part of the roof (excluding chimney).
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The panels must not be installed on a building within the grounds of a listed building or scheduled monument without special permission.
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On a property in a conservation area or a World Heritage Site, panels must not be fitted to a wall which fronts a highway. Most planners interpret this to apply also to a pitched roof facing a highway.
The role of batteries, heat pumps & EV's
How solar panels work!
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Batteries enable you to store spare energy harvested by the PV panels during the day and use it at other times. They can also be charged during cheap rate at night and used when grid power is more expensive. This applies to an EV battery as well as a battery energy storage system.
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Solar PV works well in combination with heat pumps, which consume a lot of electricity, especially in spring and autumn when heating is still required but solar generation is reasonable.
Advice on reputable installers
See list of 'Which? Trusted Traders'
Solar Powered Tring is a one-year campaign by Sustainable Tring, aiming to accelerate the uptake of solar photovoltaic (PV) systems by residents, community buildings including schools, and businesses. Solar Powered Tring is supported by a Green Community grant from Dacorum Borough Council.
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