|
HOME PAGE A brief introduction to microgeneration, what it is and what it can do for you and the planet |
|
MICROGENERATION TECHNOLOGIES An overview of different electricity and heat producing microgeneration technologies with links to further details on each |
|
ENERGY EFFICIENCY Before you look for ways to produce your own energy, it makes sense to minimise your energy needs. An outline of some energy efficiency measures you can take. |
Custom Search
|
|
|
|
.JPG) |
Solar Thermal systems produce hot water mainly used for showers, washing etc., but sometimes additionally for space heating and swimming pools. Solar radiation falling on the (usually roof-mounted) panels typically meets 50% of a household’s domestic hot water needs. There are three main types: Flat plate (cheapest, but lower efficiency) Evacuated tube (higher efficiency) Heat pipe (highest efficiency, flexible installation)
Pro
Provides hot
water with virtually no energy input
Con
Very expensive
and long paybacks (40 years +)
Verdict
Not cost
effective at current energy prices; an insurance policy
against future price rises
|
|
In the UK, the majority of solar
thermal systems are used to preheat DHW (Domestic Hot Water).
During the summer the water can be heated to very high temperatures
and little or no additional heat input is required. However,
in winter, the relatively low levels of solar energy mean that
additional heat input is required from the primary heating system
such as gas central heating boiler or electric immersion heater. By installing larger areas of solar
panels, it is possible to produce enough heat to contribute to the
space heating demands as well in new homes. Solar thermal panels, normally
cheaper, un-insulated types, are also used to heat swimming pools
during the summer. In all cases, it is essential to provide frost protection during the winter and overheat protection to prevent boiling during the summer. The potential for damage to the home, the occupants and the products themselves resulting from the very high temperatures sometimes experienced by these systems illustrate why it is essential to use only qualified designers, installers and quality products. As a significant proportion of the total cost is attributable to the installation, (labour, new hot water cylinder, controls etc.), it is not usually cost effective to install solar thermal in existing homes at current energy prices; this may change as systems become cheaper, installations more competitive and energy prices rise. The payback is obviously quicker for homes where the primary fuel is expensive, as in the case of electric, LPG or oil heating. An ever increasing proportion of the heat in homes is being consumed by DHW; this is particularly true for newer homes where the insulation standards are better and thus less heat is required for space heating. This, combined with the relatively lower marginal capital cost for new-build, implies a favourable market in this sector, particularly if novel, integrated systems are considered. Solar thermal technology may also be considered economically viable where the alternative means of compliance with regulations (e.g. Code for Sustainable Homes, Merton Rule) is prohibitive, and where it would therefore not be possible to otherwise develop a new-build housing scheme. |
|