COST/RETURN ON INVESTMENT
As has been said, solar water heating technology is not cheap. As current fossil fuel prices, particularly natural gas, are relatively low the payback for solar water heating system investments is often longer than conventional heating systems. Unlike many home improvements, solar water heating systems do, give a financial return on the investment.
It also should be noted that increases in oil and gas prices demonstrates that fossil fuel prices will not stay low forever and this perception should help customers to be satisfied with the return offered by solar water heating systems. As the energy costs of homes increases, it is reasonable to expect that a solar water heating system will add value to a property.
In general, people are not used to seeing solar panels on roofs and there can be some nervousness concerning their effect on the overall appearance of a property. People have, however, come to accept roof lights, which are not too dissimilar. Undoubtedly, as solar panels become a more common feature this currently perceived barrier will disappear. The reality is that many of the people who raise this topic will have passed quite frequently a house with solar panels fitted and not have noticed.
LACK OF EXPERIENCED INSTALLERS
The lack of local experienced installers has meant that most solar water heating systems have, to date, been installed by 'hard sell' companies with their own travelling installation teams. This sales and installation technique has resulted in extremely high prices being charged and low consumer confidence in back up service.
Solar water heating systems use heat from the sun to work alongside a conventional water heater. You will need 3 to 4 square metres of southeast to southwest facing roof receiving direct sunlight for the main part of the day for a domestic system. Space will also be needed for an additional water cylinder if required. For domestic hot water there are three main components.
There is a widely held opinion that the UK does not have enough 'sun' 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. Solar water heating can provide almost all domestic hot water during the summer months, and about a third year round. The average domestic system reduces C02 by around 350 - 400kg per year, depending on the fuel replaced, saving around £50 a year. (This information is supp!ied by the Energy Saving Trust. For more information, visit
The DT1( Department of Trade & Industry) commissioned a two-year monitoring programme of four domestic hot water solar systems located at Troon, Tewkesbury, Luton and Croydon. The results showed that systems provided an average of approximately 70% of the annual hot water requirements at the four locations. All four systems worked in winter as well as summer with 16-18% of hot water needs being met in January and December and almost 100% of hot water needs being met in both July and August.
A Further recent project supported by the DT1 monitored eight solar water heating systems side by side. The project involved taking a daily draw of 150 litres of hot water from the solar hot water cylinders of eight systems mounted side by side at Cranfield University and measuring the heat contribution provided by the eight systems. The annual heat energy contribution of the systems was then predicted from the results with the projected contributions ranging From l,OOOkWh to 1,350kWh per annum.
Flat plate systems - which are comprised of an absorber plate with a transparent cover to collect the sun's heat
Evacuated tube systems - which are comprised of a row of glass tubes that each contain an absorber plate feeding into a mainfold which transports the heated fluid.