One site, one solution

Solar thermal systems are now regarded as a key part of the microgeneration market. No longer is it a niche offering – it is now established and very much accepted throughout the heating and hot water industry. Contractors must now look towards complete, integrated systems and adopting a one-stop shop approach to gain the greatest rewards from solar heating, as revealed by the recent EST field trial findings, says Pippa Wibberley, Glow-worm.

Solar thermal has come a long way in a very short space of time – just five years ago it was still seen as being in the realm of the energy conservation enthusiast and not destined for the UK mass market. After a succession of gas and electricity price increases and strong government commitment to green energy generating new incentives to make it happen, solar thermal is now starting to be considered in a new light.

Today, the market is taking solar thermal very seriously as a viable addition to conventional heating fuels. A well designed system based solution should be able to contribute up to 60 per cent of a homeowner’s annual domestic hot water bill. The findings from the recent Energy Savings Trust report; – ‘Here Comes the Sun: a field trial of solar water heating systems’ backs up this claim, but some systems were found to be delivering as little as 9 per cent, mainly due to inadequately insulated systems or ones that were incorrectly configured or being used improperly. Get it right, and the end user will reap the benefits.

It is not too extravagant a claim to say that solar thermal has entered the mainstream of domestic and commercial heating systems. The consumer, contractor, developer and local authorities are all convinced by the proposition of solar thermal solutions as a viable and cost effective choice, especially in today’s economic climate.

The EST trial highlighted that of all the end users questioned who had solar thermal systems installed, 84 per cent were satisfied or very satisfied with their system. The reason for this, one can assume, is that the benefits of solar thermal are real and tangible. Showering in water that has been heated purely by the sun provides a certain ‘feel good’ factor, as opposed to PV which just sits silently on the roof. 

Contractors as well as one-off installers have been quick to grasp the potential of this new and fast developing market as a way of increasing their skill base and their own portfolio of services to differentiate them from their competitors. For sure, the attraction of RHI will provide stimulus to this market, but gaining the MCS accreditation is a must for installers wanting to make the most of this new incentive.

Many established manufacturers can assist with both product training, such as BPEC or Logic courses and MCS training to guide installers through what will soon become the minimum requirement to access grant funding.

For a contractor there are stark and clear advantages of standardising one simple supply route for all component parts. One supplier should be able to offer one single delivery and just one point of contact. Additional logistical and administrative work will be reduced by avoiding multiple sources for solar collectors, cylinders and controls.  Sourcing from multiple suppliers can also provide additional difficulties with additional parts often needed, to adapt seemingly cheaper system components to ensure the full system is compatible.

A single supplier can ensure all components that make up the system will be designed to work as an integrated system (eg. intelligent control that can hold off a boiler during periods of solar gain, despite the boiler being timed as being ‘on’ therefore maximising efficiency and the solar yield).

The field trial report also highlighted insufficiently insulated cylinders in some installations. Installers and specifiers should check the specification of the insulation on the cylinders they are proposing to use, and compare heat loss figures to get the best from their solar thermal installation.

All safety devices, also, should be included when sourcing from a single, approved supplier, such as an adequately-sized expansion vessel and protection vessel for the solar circuit. Requirements for unvented storage water heating systems and their installation are laid down in Part G3 of the UK Building Regulations.  These regulations state unvented hot water storage systems with a storage capacity greater than 15 litres must be safely installed by a ‘competent person’ who holds a current Registered Operative Identity Card.  G3 unvented training is available through colleges and manufacturers who may also be able to combine this with product specific training.

It is important to work with established manufacturers who offer complete and integrated systems that are also backed up by a nationwide service organization or network should any issues arise. As we head into a new generation of microgeneration products, there are huge ‘solar’ gains to be made, but integrated systems, all from one manufacturer, are clearly the way ahead.