Image by Bill Oxford




Environmental issues, sustainability and renewable energy are subjects barely mentioned, let alone discussed, in mainstream broadcasting and writing only 10 years ago but have become almost everyday items of news and consideration. Sustainability statements, increased energy efficiency, new building regulations, energy audits and renewables technologies are issues that are increasingly occupying the minds of government, local authorities and housing associations. Even some builders are recognising that business as usual is not an option. Consumer interest has also been aroused and continues to increase rapidly.


A few years ago some scientists reported an increase in the so called greenhouse gases carbon dioxide and methane in the earth's atmosphere. They predicted that this would result in major changes in climate. The increase in greenhouse gas levels was attributed to the increasing demand for energy and the resultant increase in use of fossil fuels. Although the existence of global warming caused by greenhouse gases has been subject to some dispute, it is now generally acknowledged to be a real phenomenon. Changes in weather patterns are seen as part of a real trend and not simply variations within the normal historical pattern. Climate change conferences involving governments have been held at Rio and Kyoto resulting in Agenda 21, a I commitment by states to achieve a more sustainable pattern of development for this century. The UK is committed , to reduce carbon dioxide emissions by 20% by the year 2010. A target of 10% of all UK electricity supplies to be generated from renewable energy technologies by the same year has also been set. I But these targets are likely to be just the beginning of a new focus on measures to slow down climate change. In 2002, the Royal Commission on Environmental Pollution recommended to the UK Government that the UK should aim to reduce emissions of carbon dioxide by 60% by 2050. There is likely to be a huge increase in the use of renewable energy technologies in the UK in order to work towards this sort of target. The increase in oil and gas prices intensifies the focus on efforts to stimulate the use of renewable energy.


One of the biggest advantages that solar water heating has is its ability to reduce the use of fossil fuels and thereby to help limit the emission of harmful greenhouse gases. A well designed solar water heating system installed in a family house which previously used an electric immersion heater to heat water can save in excess of half a tonne of carbon dioxide emissions per annum. If installed on a large scale, therefore, solar water heating could on its own make a major contribution toward the UK reducing greenhouse gas emissions. For the general public, solar water heating is the most practicable and effective way in which they can use and enjoy renewable energy in their own homes. People with solar systems in their houses can literally see (in those cases where there is a digital read-out on their system controller) and feel (in hot water) the benefits of the technology. Market research confirms that those householders who over the years have invested in solar water heating systems are very happy with their systems, which they find to be reliable and to make a major contribution to their water heating energy needs. Public awareness of the need to safeguard the environment is growing. More and more people are willing to make purchases which limit the damage inflicted on the environment This, potentially, creates a public more willing to use solar water heating.

The sun is the source of most of our renewable energy supplies. Energy from the sun is clean and abundant. There is a widely held opinion that the UK does not have enough sunshine to make solar systems worthwhile. In fact parts of the UK have annual solar radiation levels equal to 60% of those experienced at the equator.

However, this energy is not received uniformly throughout the year. Some 70% of UK annual radiation is received over the period April to September and 25% is received in the months of June and July.

Solar water heating technology is about using this energy and converting it into a form that can be used in buildings and industry, thus displacing conventional energy sources.