A. Solar water heating is now very efficient. About 4m2 of good quality panels on a roof should provide the average family with around 50-60% of their hot water needs spread throughout the year (100% on good sunny days, 10% on gloomy days).

A. The solar radiation received on a collector facing due south at an incline of 30° varies from approximately 900 kWh/m² per year in Scotland and the North of England, to approximately 1,300 kWh/m² per year in the South West.

A. Over half the energy falling in the UK is in the form of diffuse sunlight. On a cloudy day when there is little or no direct sunlight there may be 300W/m² of diffuse light falling on a flat horizontal surface. This is sufficiently intense to be usefully collected by specially-designed solar collectors.

Whilst the highest amounts of monthly solar radiation are obviously experienced in the summer months, there is enough radiation coming from the sun in spring, autumn and winter to make a very useful contribution to a household’s energy needs. A properly sized system can be expected to provide the following:

* 80 – 90% of all summer hot water needs.
* 40 – 50% of spring and autumn hot water needs.
* 10 – 15% of winter hot water needs.

A. The times of highest demand do not necessarily match the times of maximum solar gain – or sunshine. For example, the peak demands for space heating occur when it is cold and dark, when there is little or no sunlight, Some form of storage or back-up supply must therefore be incorporated into most systems.

A. Cost depends on the number of panels required, the size of the cylinder and on installation details such as accessibility for the scaffold and the complexity of the wiring. A typical system will cost around £3,000-£5,000 click here for more information.

A. For maximum efficiency, solar panels should be mounted on a south facing roof at a 30° angle with the horizontal and away from trees, surrounding buildings and chimneys. Fortunately, the average tilt of a UK house roof is about the optimum for receiving solar energy in the UK.

A. Collectors are designed not to collect as much light as possible as this would only overheat the system. Hot water usage and storage capacity is finite and the way in which people use hot water, and the times at which they use it will vary from day to day and have to be taken into account.

A. The effect that solar collectors will have on the aesthetics of a building is really a matter of personal taste. Some people like an array of futuristic looking tubes on the roof whereas others prefer the flexibility that panels bring. Panels can be integrated into roof tiles which makes them look more pleasing and fits in better with architectural designs. By integrating panels into new buildings, significant savings can be made on roofing materials that would otherwise be incurred.

A. In Germany, where both types of solar systems have been used for over twenty years, the market originally favoured evacuated tubes and flat plate panels were considered as second best. Today vacuum tubes comprise only 18% of the market, with flat plate panels taking a massive 82%. The end users find panels just as efficient, more aesthetically pleasing but also longer lasting with fewer faults and service calls required.

A. Evacuated tubes perform slightly better than flat plate collectors in relation to their size. Generally a vacuum installation needs around 10-12% less roof space than an equivalent flat plate system.

A. Ideally the solar panels should be oriented to face south. However, they will work with only a slight loss of efficiency sited between 30 degrees east and 40 degrees west of south.

A. Time needed for installation will depend on the size and complexity of the job. However, most systems usually take 2-3 days to install.

A. Installations with vacuum tubes usually require more service calls than installations with panels owing to the more fragile construction of tubes. Tubes can experience stress fractures caused by the expansion and contraction of the glass in tube systems which means that the vacuum fails. The whole of the heat systems in flat plate panels is made of metal; glass covers the absorber plate but rests on a washer which allows differentials in expansion and contraction. Well engineered flat plate panels are much more robust than tube systems.

A. The Low Carbon Building Programme funded by the Government offers homeowners up to £400 to assist with installing a solar energy system. What’s more, a system that is installed by a heating professional attracts VAT at 5%. However, the grant system is currently under abayance and we have reduced our prices to reflect this.

A. Planning permission is not generally required for the installation of solar panels provided your property is not listed. However, it is always worth checking with your local planning authority, especially in conservation areas and other architecturally sensitive locations.

A. Yes. However, the system will need to be specially designed. In all cases you will need a thermal store, essentially a large insulated tank of water, which will be heated by the solar panels. Then, if your boiler is compatible, the water feed to the boiler passes through a heat exchanger in the store to be preheated before reaching the boiler. If the boiler in not compatible, then a diverting valve is installed that bypasses the boiler if the water is hot enough, otherwise the boiler is utilized.

A. Yes. By installing a solar hot water heating system, you are actively contributing to cutting carbon emissions responsible for global warming. On average a typical domestic system will reduce 1 - 2 Tonnes of Carbon a year.