Solar Thermal Basics

Solar Thermal Basics

Solar Thermal, or Solar Water Heating, Solar water heaters use the solar energy from the sun to generate heat (not electricity) which can then be used to heat water for showering, space heating, industrial processes or even solar cooling.

Solar energy is the primary energy source for our planet as it is responsible for providing energy for plant growth (photosynthesis) and providing the warmth that makes our planet habitable.

While solar water heater devices have been around for over 100 years, the last 20 years have seen significant advances in absorber coating technologies, resulting in solar collectors that can reliably convert >50% of available sunlight for domestic hot water supply. A solar water heater is one of the most effective ways of cutting a household's carbon footprint by reducing reliance on dirty fossil fuel usage. By offsetting the use of electricity, gas or heating oil, using solar water heaters can also provide financial savings by reducing energy costs.

Solar Thermal is simple. First, energy in sunlight is absorbed by the solar collector, heating up the liquid inside. The heated liquid is then transferred back to the hot water tank by the circulation pump. Throughout the day solar energy gradually raises the temperature in the hot water tank. If the solar energy is not sufficient to provide hot enough water, a backup energy source (electricity, gas, etc) is used to further heat the water. The solar thermal tubes are very efficient. The diagram below is a depiction of a single solar tube and how the energy is absorbed from the sun. Almost 90% of the sunlight making contact with the tube is converted directly into heat energy for your home or business.

For the average household, 30% of the energy bill is for heating water. By installing a solar water heating system using a solar collector the water heating bill can be reduced by between 50-90% (depending on location and hot water usage patterns). Solar hot water is therefore one of the most effective ways to reduce your household energy bills!

In addition, water heating accounts for around 30% of CO2 emissions. Installing a solar water heater can provide between 50-90% of a household's water heater energy needs and so reduce CO2 emissions by more than 20%.