Solar Thermal Energy
Solar Thermal is a clean and highly efficient means of using renewable energy from the sun to provide the hot water used in the home. The basic principle is easy to understand. If you unroll a garden hose on the ground and leave it exposed to the radiant heat of the sun, in a short time the water in the hose will become warm.
Solar thermal collectors work in very much the same way, only more efficiently. Usually, but not exclusively, roof-mounted solar collectors will be connected to one of the coils of a twin-coil cylinder using a sealed circuit containing a special glycol/water solution. This fluid not only withstands the high temperatures in excess of 200°C on a summer day, but also will not freeze in temperatures down to –25°C. The pump in the system circulates the heated fluid from the panel to the cylinder where the heat is transferred to the stored water through the lower coil.
Solar Thermal has unique installation features. The Solar Pump Station incorporates an air eliminator that allows the system to be both filled and purged of air in a single operation. Unlike other arrangements there is no need to install an air vent on the roof and also no need for regular maintenance. Solar Thermal integrates easily with conventional water heating systems.
Many people believe that solar panels only work in the summer, however this type of free energy is available throughout the year. From May to September, Solar Thermal can produce 100% of the energy required for heating your domestic water. The Solar collectors operate not just with direct sunlight, but also diffused sunlight, so they even work on cloudy days. On average Solar Thermal can provide up to 70% of your hot water needs per year, for free!
Solar Irradiation in the UK and Ireland
This diagram shows the total average solar radiation falling on 1m2 surface, inclined at 30° to the horizontal, measured in kilowatt-hours. The average property requires approximately 3,000 kWh per year for domestic water heating.