Evacuated tube solar panels are the priciest but most efficient type of solar thermal panels. They have got the potential to reach 90% efficiency, which means you can produce more heat compared to other types of solar hot water panels.
How do evacuated tube solar panels work?
An evacuated tube includes a small glass tube that is kept in a larger tube. The air is pumped out of the space in between the inner tube and the outer tube, which creates a vacuum thermal insulation layer. This layer decreases heat reduction from the solar collector.
The inner glass tube is coated using a selective light absorber which is often made from light-weight aluminum nitrate or sometimes titanium nitrate oxide. It can help boost the absorption of the sun’s rays. An absorber plate runs through the inner glass tube. Generally, it is made from copper, and absorbs heat then moves it to a heat transfer liquid.
After the transfer liquid gets hot, it evaporates and turns to steam, which rises to the top of the panel and the heat is transferred via a heat exchanger to another liquid. The cycle, following that, will start again once the transfer fluid condenses and falls back into the evacuated tube.
Seeing that evacuated tube solar panels are the most expensive, you may be unclear if they are best for you. Take a look at the benefits and drawbacks of these types of panels to help you decide.
Advantages
Produce a more heat compared with other systems
Because the panels are up to 90% efficient, you can generate a lot more heat with evacuated pipe panels compared to flat plate collectors. You might spend more on the initial installation but you should be able to heat more water, which will in the long term save you money.
You can save up to £60 each year on fuel expenses
If you have gas heating, you can expect to see a saving of £60 each year on your heating expenses. Solar hot water is free to generate, so you should see the savings on your bills within a few months.
Preserve 270kg CO2 in comparison to gas
Thermal solar panels are undoubtedly a good way to cut your carbon footprint. You’re generating your hot water from the sun, a renewable resource, so that you’re doing your small amount to lessen the use of non-renewable energy resources in addition to reducing global warming.
Get free hot water all year round
Although the UK’s winters are cold, you can still get some free hot water out of your solar panels through the entire year.
Get an average of £349 every year for 7 years through the Renewable Heat Incentive (RHI)
If you get your system installed by an MCS-registered expert , you might be able to make money for generating heat with your solar panels through the government’s Renewable Heat Incentive (RHI). A 2m2 system, which is generally sufficient for a 2-person house, may generate you £200 every year from your RHI, while a 4m2 system could fetch you £345.
Downsides
You’ll probably need a backup heater
In the winter weather, you might not manage to get your hot water to the desired temperature. What this means is you’ll need a backup heater, which will of course cost money to run.
Solar thermal panels are not compatible with combi boilers
Combi boilers supply instant hot water, and they don’t have a separate hot water tank. They aren’t suitable for use with solar thermal panels, so if you want evacuated tube solar panels and you have a combi boiler you will have to replace your boiler. This will increase the price by at least £1000.