A photograph of a flat plate collector by "Solarcoordinates"

Despite common misconceptions, solar water heating is suitable for the UK’s commonly overcast weather, even producing energy in winter. In a house with a normal solar water heating system, this eco and wallet friendly system supplies 50% of the energy required in a house.

The system works by pumping water up into the collector on the roof which exposes the water to the solar energy. This heats the water from around 4 or 5 degrees Celsius to a luke-warm temperature of around 25 to 35 degrees on an average day. The rest of the heating is done by a standard boiler or immersion heater but on summer days there may be no need for any additional heating after going through the solar collector.


Photograph of an evacuated tube collector by "RJL20"

Types of Collector

This can normally be split into two categories, the type required depends on space and money available.

  • Evacuated Tube Collectors work by creating a more substantial vacuum to stop heat loss to the outside through convection currents, in short this means they are more efficient and therefore a smaller size panel is required compared to flate plate collectors. However this comes at an increased cost, they are less efficient in cloudy conditions and can be damaged by large hail.
  • Flat Plate Collectors require a larger panel as stated above, but have the advantages of being the cheapest, strongest and most widely used solar water heating system. Another advantage is that on listed buildings or in conservation areas, the panels look similar to conservation roof windows, making it more likely to be accepted.


A diagram showing two systems for solar wate heating. Whereas C cannot store the solar heated water, D has a rooftop reservoir to store water and keep it at the solar heated temperature.


Whilst it is most common to place any solar system on angled roofs, they can be fitted anywhere facing 45 degrees either side of south with clear access to sun light such as in the garden, shed or conservatory roofs or flat roofs when built at an angle. One problem can be large overhanging obstacles such as chimney stacks, trees or surrounding tall buildings which can block out the sun at certain times of the day. Thus reducing the efficiency of the system.


Grants and Payback Period.

The Low Carbon Buildings Programme has grants available of £400 regardless of the overall cost as long as it accounts for 30% or under of the installation from an accredited professional installer like Marble Construction. This is before VAT, although the rate is only 5% when a professional installer is used. It is also worth checking locally to see if there are any additional grants available.

The payback period depends on what type of heating system you had previously and are subject to change as fuel bills change in price. However this is more good news as fuel and energy prices are likely to increase, therefore increasing the savings of a solar heating system. Genersys is a manufacturer of solar  collectors and have calculated that with inflation, “most thermal systems offer a pay back of between 6 and 15 years.”

It is important to remember that a solar heating system will also increase the sale price of the property.

Frequently Asked Questions

  • What is the life span of a Solar water heating system? Flat plate collectors last around 35 years.
  • What is the difference between a solar collector and a solar panel? Solar collectors are for water heating, solar panels generate electricity.
  • Do I need planning permission? No planning permission is needed unless in a conservation area or listed building.
  • Is there any upkeep work? An occasional clean will maintain efficiency, but this is only needed as often as cleaning out the house’s gutters.
  • How do I get a free survey and estimate? Phone Marble Construction on 0844 813 1111 or email sales@marbleconstruction.co.uk.



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