Solar thermal water heating systems use free energy from the sun to heat water which you can use in your home.
Some solar thermal water heating systems just supply hot water that you can use through your hot water taps or shower, whilst others feed it through underfloor heating systems.
You should be aware though, that the Domestic Renewable Heat Incentive scheme only applies to those systems which provide hot water for use in your home, not those which supply heating.
Solar thermal water heating systems are quite efficient and offer low maintenance. However, they will require a back-up water heating system such as a central heating boiler or an immersion heater.
Estimates vary widely, with claims for solar thermal water heating systems saving between one third and three quarters of your annual water heating costs, depending on the amount of sunlight the systems are exposed to. Solar collectors for solar thermal water heating systems are therefore normally installed on a south-facing roof.
Solar thermal water heating systems are available as either solar thermal evacuated tubes or solar thermal flat plate panels, both of which are referred to as solar collectors.
The solar collectors have copper heat pipes inside containing ‘solar fluid’ which absorbs heat when sunlight shines on them.
The evacuated tubes and flat panels have advanced coatings on their surface which maximise the absorption of heat from the sun.
The heated ‘solar fluid’ is circulated by a pump through a secondary solar coil inside a hot water storage cylinder and the heat is transferred to water inside it and then to your taps.
The ‘solar fluid’ is then pumped back to the solar collectors to be re-heated, starting the process again.
Solar thermal evacuated tubes are made from tough, insulated glass and, due to their cylindrical shape, are able to absorb sunlight at the best angle to their surface for most of the day.
This can make solar evacuated tube systems more efficient than solar flat plate systems, which are at their most efficient when the sun is directly overhead.
Typically, solar thermal evacuated tube systems will have 20 – 30 tubes and, in order to achieve the correct angle to maximise exposure to sunlight, can be fitted directly on to the roof tiles, onto a building façade or fixed to an ‘A’-frame.
Individual solar thermal flat plate panels are approximately 2 – 2.5 square metres in size (for a typical three bedroom home you need at least two panels) and can be fitted directly onto the roof tiles.
In new-build situations and house extensions, solar panels can be built into the roof structure in place of the tiles. Being flat, solar flat plate panels are most efficient when the host roof faces directly south.
We have processed over 30,000 applications for Government Heating and Insulation Grants
The typical cost of installing 4 square metre solar thermal water heating system should be between £4,000 and £5,000 including V.A.T. at 5%.
This would include the solar panels, a pump and a hot water cylinder but would be dependent on the number and type of solar panels and the suitability of your existing plumbing system. Since little maintenance is required, ongoing costs are fairly minimal with some systems needing fresh anti-freeze in the ‘solar fluid’ every three years.
According to the Energy Saving Trust® if you currently have an LPG boiler you should save around £95 on your water heating bills per year, receive around £380 in RHI tariffs and save 300kg of carbon emissions.
The Government’s own Domestic Renewable Heat Incentive Tariff Calculator can provide you with an estimate of your tariff receipts. You can find it HERE.
For solar thermal water heating systems to be effective you will require approximately 5 square metres of roof space which faces south for the main part of the day.
If your roof does not face due south, then an evacuated tube system would be more appropriate, though even in cloudy weather the solar tubes and solar panels will both absorb the sun’s radiation.
Alternatively, solar panels or solar tubes can be fitted on a flat roof or on an ‘A’ frame on the ground.
It may be possible to fit a solar heating coil conversion kit to your existing hot water cylinder, otherwise it will need to be replaced with a new cylinder which has a solar heating coil built in.
Alternatively, if you have enough room, you could have a separate, dedicated hot water cylinder just for the thermally heated water.
Most gas, oil and LPG central heating boilers are compatible with solar thermal water heating systems.
But if you have a combination boiler and no hot water tank, solar thermal water heating systems may not be compatible. In this case, if you have enough room, you could have a separate, dedicated hot water cylinder just for the thermally heated water.
Planning laws were relaxed in April 2008 to exempt the installation of solar thermal water heating systems from the requirement for planning permission in most homes.
However, if your home is in a conservation area or is a listed building you may still have to apply.
We have access to the largest database of installers of solar thermal water heating systems in the UK.
Simply complete the form on this page and we will introduce you to up to three accredited solar thermal water heating systems installation companies for you to request quotations from.
We do not charge you anything for this service and you are under no obligation to place an order with any of the installers that we introduce you to.
Affordable Warmth Scheme
Another Government scheme to help with heating systems in domestic households is the Affordable Warmth Scheme. This provides grants to help to replace broken heating systems and to install insulation in homes where one of the occupants receives a qualifying State Benefit, Tax Credits or other allowance.
More information about the Affordable Warmth Scheme can be found HERE.