 Solar Thermal and Solar Photo Voltaic
Special Interest Team
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Introduction - Solar photovoltaic
Solar photovoltaic (Solar PV) is the technology by which electricity is generated directly from sunlight, a process usually carried out by panels containing specially processed slices of silicon, the material from which our various electronic devices are made. Silicon is very plentiful, but some of the manufacturing processes involved use a lot of energy. This is a rapidly - developing technology and is of importance because electricity is the most flexible and versatile form of power used by mankind and solar PV offers a way of producing it that has no adverse effect on the environment other than that caused by the manufacture of the system components, and their eventual disposal.
A small PV system can be used to generate power in a remote area where there is no mains electricity available. Weather stations, radio transmitters, road signs and navigation beacons may be powered in this way, with rechargeable batteries providing continuity of supply during the hours of darkness.
In the case of domestic PV installations, it is more usual to convert the low voltage output of the solar panels into mains-type electricity which is consumed by the household appliances, with any excess being exported from the house into the mains supply grid for consumption by other users. A typical installation would consist of several PV panels mounted on a south-facing roof, an inverter to change the panels' output to alternating current, and the associated wiring, and could produce several kilowatts of electrical power in full sunlight. Planning permission may have to be obtained, and an agreement made with the electricity supply company to buy the surplus power. Administrative difficulties and the high price of the equipment have hindered the widespread application of solar PV in the UK until now, though in Germany for instance there are many systems already in use. There is currently a lot of research going on to improve the performance and price of solar PV.
Given that there would appear to be the possibility of a shortfall in UK electricity production within the foreseeable future, small-scale stand-alone systems may become popular to supply essential needs e.g. lighting, freezer, radio during periods of mains power failure.
This SURE Special Interest Group is now collecting information about the various systems, components, suppliers and installers, and will keep up-to-date with technological developments. It will provide prospective users of PV with information about regulations and planning, grants and finance.
Introduction - Solar Thermal
This term applies to any arrangement where warmth is obtained directly from sunlight. This may be for space heating, two everyday examples being greenhouses and conservatories. Water heating is another application. In its simplest form, water is passed through a panel exposed to sunlight, is warmed, and if not used at once, is stored for use later. Both of these applications of solar thermal power can be found at Otley Courthouse Arts Centre, where as well as the pleasantly warm glazed area by the entrance door, there are solar panels on the South facing roof which contribute to the hot water supply for the building.
The wider use of solar power for water heating in the UK seems to have been hindered by two popular misconceptions, the first being that it doesn't work in cold weather, and the second being that there is not enough sunshine in Great Britain to make it worthwhile. A properly designed system will make a useful contribution to a family's hot water needs on a bright winter's day, and on a summer's day with a few hours sunshine around noon may well supply all its requirements. Shorter periods of sunshine or light cloud will reduce the system's output, but will still give some useful warming so that less fuel needs to be consumed to heat the water to the desired temperature.
There are numerous solar hot water systems on the market in the UK, some of which are quite complicated and require professional installation, and others which are simpler and suitable for self-installation. Some systems operate without the use of mains electricity which may increase their appeal to some prospective purchasers.
There are currently at least two professional solar installers in the Otley area.
The recent increases in fuel prices have made the fitting of a solar hot water system a more attractive proposition than it once was and a new installation will now pay for itself relatively quickly, as well as reducing CO2 emission from day one. Grants may in some cases be available. Planning permission may have to be obtained in a conservation area such as Otley town centre - although recent legislation introduced on 1st October 2008 now allows a solar panel to be fitted on the roof aspect facing the highway -- ie the most visible side. This is great news..
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Solar Trade Association
Promoting Solar Thermal
in the UK
STA ...
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Jump in -- join the team -- share your ideas -- let's do this together
info@SURE-energy.org.uk
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