Solar Thermal

Heating water can be achieved in many ways, in fact it is far easier to heat water than it is to generate electricity. From air source heat pumps and ground source heat pumps, a solar thermal system is cheaper and quicker to install, though there are additional piece of equipment that you need. Such as a storage unit for hot water if not already installed and a boiler which is compatible.

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What Are The Different Types Of Solar Thermal And How Do They Work?

A solar water heating system can plugged into most existing boiler systems, although if you have a combi boiler you will need an additional piece of equipment and a twin coil cylinder to ensure maximum compatibility. The suns rays are caught by similar technology to what is effectively a solar panel, only in this instance they are termed solar collectors.

These tend to be fitted to the roof and transfer the heat generated into a converter which then goes on to heat water which is contained in a hot water cylinder ready to be used. Occasionally the temperature may not be sufficient, in which case the water can be funnelled through to a boiler or immersion heater to further heat the water to the desired temperature. This however still uses less alternative fuel as the water has essentially had its temperature raised already.

There are two types of solar collectors, evacuated tubes which are of glass assembly and utilise the differential between external and internal air. These are probably the best format to get the most use out of solar thermal during the colder months. The second type is called a flat plate collector, these work in a similar fashion except with one sheet of glass and a metal base which converts the sun rays into heat through warming of the plate itself.

A brief overview of the comparison between flat plate collectors and evacuated tubes:

  • Flat plate collectors are cheaper due to the manufacturing process being less complicated.
  • Evacuated tubes are lighter and can be a the preferred choice for easier roof assembly.
  • If you are looking to use solar thermal for supplying water to the central heating system, Evacuated tubes provide up to 40% more heat on average and can warm to higher temperatures of 250F.
  • For climates that experience colder climates use Evacuated tubes for better efficiency when winter hits.

What Are The Benefits Of Solar Water Heating Systems?

As with many renewable technologies, the benefits are obvious. Lower energy bills, less carbon emissions used through the chain. No fuel deliveries and in essence in combination with other types, you can be national grid free and even earn money back from other people’s home use thanks to being ahead of the curve. However, there’s more to benefit from:

  • The release of carbon dioxide into the atmosphere from the burning of fossil fuels for energy is no longer required nor sustainable. By switching you can save 300 to 500kg annually, far less than other systems but still a contribution.
  • Those solar rays only end up being hot upon reflection of objects and land, so whether it is cloudy or a cold atmosphere electricity can be generated throughout the year even when it is snowing. Though the collectors obviously need to be kept from of obstructions such as dormer shades, and snow.
  • You can save money on your energy bills, especially if its purpose is dual usage.

What Are The Costs Of Solar Thermal And How Much Can Be Saved Or Earned?

The government’s Green Deal is probably the best way of making money back on this type of investment. The savings are not as high as those made possible with other types of sustainable energy sources. That said, when using evacuated tubes you could essentially feed through the heated water to the central heating system. This in itself would almost double the value of any installed solar thermal device, as it then has dual purpose.

One average you may be looking at a saving of £60 to £70 a year on energy bills by switching to this form of solar technology. The government’s Domestic Renewable Heat Incentive (DRHI) based on a four bed detached home could possibly reward you with a windfall of £250 to £500 simply for using a self generated power option rather than the national grid. Though these payments are not continuous.

With the cost of a solar water heating system being on average £4000 to £6000, depending on scale of the panelling and white type you use. Flat plate collectors work out cheaper than evacuated tubes, then you can recoup your investment within 10 to 15 years. However, if you do utilise a larger set of evacuated tubes, you may increase savings and generated income from the government and power the central heating system in part, reducing the time it takes to recoup investment by almost half.

Is There Much Maintenance With Solar Water Heating Systems And Are There Any Other Issues?

Being another fit and forget technology, maintenance is more a form of monitoring for any issues that might arise. Checking anti freeze for low levels or smells and keeping an eye on the energy levels generated, if below an average there may be something wrong. Simply receive a check up and service by a qualified installer every three to seven years for maximum peace of mind. Cleaning can be attempted by yourself of a window cleaning company that specialises in renewable technology surface cleaning at heights.

Out of all renewables, parts are probably cheaper in this form of solar panel collector. The two parts which will need the most attention during its lifetime are the pump and the anti-freezer, which could cost approximately £90 and £100 respectively. Make use of any warranty should repairs become noticeable or too many checks have been needed on the installed equipment. If you do get work carried out, keep a record and log book and receipt from the installer detailing checks and any repairs made.

Is Solar Thermal The Right Renewable For You And Your Home Or Business?

Space can be an issue for this renewable energy source as it’s not just the solar collectors that require consideration. Depending on your boiler set up, you will probably need additional space to fit a large hot water cylinder and need to replace your current boiler with a hot water tank. Most homes only have a cold water tank.

For the return on investment you will need to look at government schemes to see a quicker rebate as the savings as detailed above are not as generous as with other types. You will also need around five square metres of roof or wall space to make the system beneficial. as long as the panels are night higher than your current building’s construction, you will not need planning permission however. Ensure you get a site survey completed to assess your home or business location for solar coverage.