Heat your home and enjoy free hot water from solar radiation

What is Solar Thermal?

A short introduction to solar water heating

Solar water heating systems (known as solar thermal) use free radiation from the sun to work alongside your conventional water heater. They are designed to meet 100% of your water heating needs during the summer, but will require the backup from a boiler or immersion heater during winter.

Solar thermal systems do not require bright sunlight in order to function; they simply require light and can still heat water even on a cloudy day as solar radiation is still present.

The technology is well developed and an effective means of using solar energy in the UK.

How Solar Thermal WorksSolar Thermal Options

The Benefits of Solar Thermal

Cut your water heating bills and reduce your carbon footprint
  • Solar thermal can provide almost all of your hot water during the summer months and overall about 60% of your annual hot water
  • Solar thermal is an easy to integrate solution which can reduce large energy bills quickly
  • This significantly reduces your impact on the environment as the average domestic system reduces carbon dioxide emissions by around 400kg per year, depending on the fuel replaced

How Solar Thermal Works

The key technologies required to benefit from solar radiation
Solar panels - Solar Thermal Collectors

Solar Collector

The key component of a solar thermal system is the ‘collector’. These can be either tube arrays or flat panels, and are typically installed in an array on the roof of the property. The collectors contain specially coated reinforced glass tubes to capture the radiation from the sun, which is then turned into heat.

There are numerous solar thermal collectors on the market to choose from. We will help you select the very best collector panels or array for optimal performance and to suit each individual’s requirements in terms of water heating needs, property size and budget.


Heat Exchanger

To harvest solar heat a pump is used to transfer the heated fluid (normally a mixture of water and glycol) from your collector to a heat exchanger inside a water tank in your house.

Typically you will require a specialised ‘twin coil’ water cylinder that contains both a coil heat exchanger for your free solar heat and a backup immersion coil that is connected to your existing boiler to provide water heating when required.

Is my Home Suitable for Solar Thermal?

How to determine whether you would benefit

Solar thermal hot water heating systems are definitely worth considering if you have a mainly south-facing roof or garden space with little or no shade.

Although a south-west or south-east-facing location would also be effective. Shade on the collector panels at any time of day will reduce the performance. In addition to heating your home, they are particularly suited to heating swimming pools.

Planning permission is generally not required for domestic solar thermal. Exceptions apply for listed buildings and buildings in conservation areas.

The Met Office website has useful radiation maps. The higher the radiation figure, the greater the effectiveness of your Solar Thermal system.

View Orientation Guide

Choosing Solar Thermal Collector Systems

Evacuated tubes vs flat panel systems
Solar panels - Solar Thermal Collectors

Evacuated Tubes

Even though these panels can be more expensive they utilise a vacuum to retain heat in the system. The panel comprises a number of individual tubes, each being separately sealed and containing a small amount of a fluid.

Heat is extracted by evaporating the fluid in the tube which then condenses at the top, releasing the heat to the fluid circulating in the closed loop. The delivery temperature for evacuated tubes is higher than conventional flat panels and they operate more efficiently.


Flat Panel Systems

Solar thermal flat panels offer far greater installation flexibility as they can be integrated into the roof for a neater installation. Also, they tend to be more robust and are generally considered more aesthetically pleasing.

The collectors work by circulating water through the whole panel, but consequently they can be less efficient when compared to evacuated tube types.

Book Your FREE Solar Thermal Survey Today

Contact us today and we will arrange your free initial site inspection as soon as possible to assess your property’s suitability, and discuss all of the Solar Thermal options available to you.


AES Solar Thermal Maintenance

We can provide a regular service that keeps your system performing optimally

Most systems have an average lifespan of over 20 years and require very little maintenance.

A yearly check by the householder should be supported by a professional solar thermal service every 3-5 years to keep your system performing optimally. With extensive experience in the design, installation and maintenance of solar thermal systems over the years we have gained a good understanding of what is required to keep thermal systems operating correctly.

Book Solar Thermal Maintenance

During a Solar Thermal service we would carry out the following system checks:

  • Check Glycol strength for antifreeze protection
  • Check colour of Glycol
  • Check pumps are in working order
  • Ensure pipework lagging is in good condition
  • Check system pressure
  • Check pressure relief valves
  • Check pumping station is set correctly (providing we have the Design Specification)
  • Check flow rates
  • Visual inspection of solar thermal panels