Utilizing solar energy and converting it into heat—which is then transported into your house or business's heating system in the form of hot water and space heating—is the fundamental idea behind solar thermal heating. When combined with a boiler, collector, or immersion heater, roof-mounted solar panels serve as the primary source of heat generation. In order to keep the water from freezing, the solar collector uses heat from the sun to warm a transfer fluid, which is often a solution of water and glycol (antifreeze).

 

Your home's water tank houses a heat exchanger, which receives hot water from the collectors. The water within the tank will then get heated by the heat from the exchanger. The water will return to the collectors to reheat when the liquid releases its heat. When there is enough heat present, a controller will make sure the fluid flows to the collection.

 

The efficiency with which solar thermal energy is converted to heat ranges from 70 to 80%.  A solar thermal system does, however, take a little more work during installation because it needs to be connected to your current plumbing, which calls for a hot water tank.

 

Solar thermal systems should generally be sized to meet 70% of your hot water demand and your boiler provides the rest. 

 

Solar thermal is likely to be replacing gas, or possibly oil in rural areas. So, if we’re replacing oil, solar thermal would lead to greater emissions reductions.

 

A solar thermal panel will yield annual energy of 150kWh/m2 which is more efficient than solar PV.