So what is Solar Thermal

Solar thermal is a completely different technology to Solar electric (PV), other than utilising the sun's energy, there are not many similarities.

Solar thermal involves capturing the sun's energy in the form of heat, then transferring that heat into a body of water to enable it to be used in your home. There is no conversion process involved, this is why solar thermal is far more efficient than solar PV.

Solar Thermal Variations

The solar thermal operation can be achieved in several ways, each having its own advantages and disadvantages, the key things to really consider with any solar thermal system are its efficiency (the ability to transfer the maximum quantity of heat energy at any given time into your hot water store) and the system price. These two factors will determine how quickly the system will return its investment and also how great your energy savings will be post payback.

The two main types of technology in use in the UK are flat plate and evacuated tube. After around 12 months of research and product testing, we decided we would only offer the evacuated tube technology. We believe this offers the greatest performance and although historically more expensive, recent changes in the UK market has meant that evacuated tube solar panels can now be purchased for equal and often cheaper costs than the flat plate equivalents.

How do evacuated
tubes work?

The Frenergy evacuated tubes are such a simple technology, yet the manufacturers have perfected this so much that they are 93% efficient, compare this to an average solar electric panel with an efficiency between 7-15%

The outer glass is a dual wall construction with a vacuum in the middle, this is a single piece construction to ensure the vacuum can never be reduced over time.
The purpose of the vacuum is to act like a thermos flask by limiting heat escape by convection or conduction.

The inner glass wall has a dual use coating, black on the outside to absorb as much solar energy as possible and silver on the inside which stops that captured energy re-radiating outwards.

The core of the tube is a copper heat pipe, this is held in place by aluminium fins which also aid in temperature conduction and spread.
The heat pipe is sealed, again containing a vacuum.

Inside the heat pipe is a very small quantity of non-toxic fluid, this is the key to the operation of the system, as solar energy is absorbed, heat is transferred into the heat pipe, the fluid very quickly boils away to steam where it travels up the pipe to the only place where it can expand, the larger 'bulb' at the top. This 'bulb' is inserted into the header manifold where heat is conducted into the system fluid.

As heat is drawn off the bulb, the steam condenses back into water and passes back down the pipe to begin the whole process again.

Without the manifold to extract heat from the bulb of the heat pipe, it is capable of reaching several hundred degrees Celsius! this gives some idea of the efficiency of the tube.

How is the system operated?

Operation of the system is completely automatic, the whole system is kept functioning at its optimum by a solar controller like the one pictured on the left.

The controller compares various system temperatures then decides on the appropriate action to take in order to extract the most available solar energy. It can also give feedback on the system's status and can even tell you the temperature of the available hot water!

All this means that you needn't worry about the technology involved, opening this web page is more complicated than the operation of one of our solar thermal systems!

What are the benefits of Solar thermal systems?

The main benefit from a solar thermal installation is that it can provide all your hot water needs throughout the summer months, with the only occasional top-up from the boiler or immersion on overcast days. This is obviously a huge saving on your conventional heating method.

Once the cost of the installation has been paid back (Usually in 5-10 years) it will mean you begin to make financial gains and with the life expectancy of the solar panels being in excess of 25 years you can see it is a sound investment.

In these times of rapidly increasing energy costs, the payback time of a system is getting shorter and shorter, after this the savings are becoming larger and larger!

You will also be making savings that are less tangible, but never the less just as important. You will be reducing your carbon emissions and making a major step toward the holy grail of being carbon neutral.

As well as the benefits above, you will be making an environmental statement about your desire to change our world for the better.

Are there any other applications for solar thermal systems?

Absolutely yes! If you have a hot tub or swimming pool, solar thermal systems can provide massive savings on heating costs. If you have one of these, you will already know the costs involved of keeping your water up to temperature, if you are thinking about the installation of a hot tub or pool, you could be quite shocked about the amount of energy required to heat such a quantity of water. A solar thermal system in a pool or hot tub application can provide much larger savings and quicker payback times than with a standard hot water solar system.

Call us for more information! - 01604 211200

How can you get a system installed?

Simply call, or email us to arrange an appointment to suit you. We will visit to discuss Solar thermal technology, explain all the benefits you can expect and answer any questions you may have.

We do not employ pressure selling tactics, in fact we will not even offer you a price during our visit, we will go away, design a system that suits your family and your home then provide a written quotation for you to view and decide upon in your own time. We cover all of Northampton and Northamptonshire, so call us today!