Solar thermal energy is simply the technology for capturing the heat of the sun and using it to heat water.
As the sun is the most abundant source of energy available to us all on earth, it makes perfect sense to use this energy to heat the water our homes use.
Solar thermal energy systems are becoming increasing popular compared to other "green" solutions because they are designed to capture the energy as heat.
Solar PV uses the sun to create electricity where as solar thermal just uses the heat to heat water.
What is needed? To harness the suns energy in this way to heat water you will need collectors, a storage tank, an expansion tank, solar station with pump, controller, solar fluid, mounting hardware and piping.
The storage tanks can be combined with existing heating systems and the solar station includes the pump and valves needed to work whole system.
How it works? The sun will heat the solar fluid which is in the solar collector on the roof.
For a typical home, two or three collectors are put on the roof.
These will be made with glass that can withstand any type of weather.
The controller monitors the systems temperature and will detect when the solar fluid is hotter than the water in the hot water tank.
The pump in the solar station pumps solar fluid from the collectors to the hot water tank.
This solar fluid flows through a pipe which is coiling inside the hot water tank heating the water in the tank.
Then this water can be used in the home.
The solar fluid is then pumped back up to the collector on the roof to continue to be heated by the sun again.
Does it work in winter? Because it takes the same amount of energy or sun to heat the water in the tank whatever time of year it is, it will perform less well when there is limited daylight available, so in the winter it won't work as well but it will still give you savings on your winter fuel bills.
It will provide you with hot water for approx 70-80% of the year.
To get the best benefit your solar roof collectors will need to be placed on a south facing roof with a 45 degree tilt towards the sun in an un-shaded location.
You can also use solar thermal energy to cool your home.
You can get a solar thermal chimney which is a device that simply pushes the heat out of your house during the summer.
The chimney will get heated during the day, and warm air inside will rise up and out which in turn will pull cooler air into the house.
Other benefits include the cost of installation.
Solar thermal systems are much easier and safer than PV panels to install.
This means the installation cost will be far lower and they could also be installed by a DIY enthusiast.