Here comes the sun

The Cotswold Energy Efficient Centre (CEEC), has been installing renewable energy systems throughout Gloucestershire for over five years. The company boasts an impressive showroom and having picked up five national renewables awards in five years, really does know its stuff. The company’s Andy Buchan outlines the merits of solar thermal.

A solar thermal hot water system can typically provide all of your hot water requirements during the summer months and a good proportion throughout the rest of the year. It can be installed in your home or for larger applications, such as swimming pools.

Solar is a clean energy source. The biggest bonus is the knowledge that you are heating your hot water for no cost! There is also less stress on the back up fossil fuel supply resulting in reduced running costs and appliance servicing. There is also very little maintenance with solar and it only requires a health check (always comply with manufacturers requirements).

In a nutshell, solar thermal is the choice for you if you want; 

1.     Hot water throughout the year: the system will work all year round (but you’ll need to heat the water further with a boiler or immersion heater during colder months).

2.      To cut your bills: after you’ve paid for the installation, sunlight is free!

3.      To cut your carbon footprint: solar hot water is green and clean!

Types of solar

There are two main types of solar in the UK – flat plate collectors and evacuated tubes. Both systems use the same tanks, pipe work and controls to collect both defused and direct energy. The evacuated tubes, however, incorporate a parabolic mirror which generates more energy in poorer light conditions so they perform better in the winter when there is less daylight and when the sun is lower.

What to expect during and after installation

A normal domestic installation with a tank change fully commissioned would take approximately three days. As with all renewables, it is important to engage a MCS accredited installer who will only use quality products and is competent for the work.

For the end user there are no controls to set or adjust. The temperature differential controller (TDC) works on a temperature difference between the collectors and tank and is an automatic operation requiring no other adjustments.

Our experience at CEEC

We at CEEC have completed about 200 installations of solar thermal systems now ranging from light commercial businesses (football clubs, laundry rooms, hotels, swimming pools) to residential properties.

From our experience we know the more work solar has to do the quicker the payback on the install price.  For example, a two bed house with a shower/ basin and kitchen has little hot water demand. The approximate price for a solar installation (2 panels, new tank etc) would be £4,000.  The energy saving in fuel cost would be £100 per annum, giving a payback of 40 years.

However, a 50 m² swimming pool with summer running fossil costs of £2,300 would require 16 m² of collectors. This is likely to give a payback of only 4 years.

Therefore the more water to heat, the better the investment.  The two examples go from one extreme to another. With the proposed Renewable Heat Incentive (RHI) tariff this will make solar thermal a more attractive alternative to producing hot water as we can rely on our sun as a renewable and sustainable source unlike burning fossil fuel which has no future!

Richard Page from Gloucester had two Worcester Greenskies Solar Panels installed in 2006 on his three bed semi detached home.  He says: “Andy, of CEEC, gave us an honest rough estimate of a 12 to 15 years payback.  While it’s difficult to accurately estimate the savings on our fuel bills, the energy usage has reduced dramatically.  By comparing two one-year periods (01-02 and 06-07), I roughly estimate a payback of 13 years, which is likely to increase further as gas prices increase.”