Case Study

Case study: Installing a Grant solar thermal system

This Wiltshire home was extended to transform the property into a five-bedroom house. When the homeowners started this project, they decided to take the opportunity to add a renewable technology into their heating system by utilising the additional roof space being created by the extension. A Grant solar thermal system was chosen and installed, helping the family to not only significantly reduce their carbon footprint but also lower their monthly heating bills.

Grant solar thermal installation

Solar thermal systems from Grant are supplied in kits, making the process of selecting and ordering the right components straightforward for installers. Each kit includes the required number of Sahara collectors, a roof mounting system, expansion vessel, pump station, controller, pipe connections and solar fluid. For this installation, a two collector in-roof slate kit was chosen with the Sahara collectors portrait in their orientation.

“When we were designing the solar system, there were several factors we took into consideration,” comments David Croker of Howard Croker Partnerships Ltd, the installing engineer.

“The orientation of the roof is southwest facing and there are no trees which could cast the roof into shade, both of which are really important. The home is occupied by two adults and two children so we calculated their estimated hot water usage and selected the two collector system alongside a 300ltr high performance DuoWave hot water cylinder.

“An in-roof mounting arrangement was preferred by the homeowner, fitting flush into the roof assembly and reducing the amount of roof slates required for the extension. The scaffolding was already in place by the builders completing the extension so the installation was simple from start to finish.”

A WinterSOL kit has also been installed as part of the system. Grant’s WinterSOL is designed to provide a fully heated cylinder during periods when there is a low solar gain. Using a simple switch to operate the WinterSOL, the homeowner can select the ‘Winter’ mode which will allow their gas boiler to heat all the water within the cylinder, ensuring that the hot water demand can be satisfied. When solar gain is restored, the WinterSOL switch can be reverted back to the ‘Summer’ mode to allow the solar thermal system to operate at maximum efficiency.

The addition of a Grant solar thermal system has significantly increased the overall efficiency of this home’s heating. With the solar thermal system fulfilling the majority of the hot water requirement, the gas boiler is only needed to meet the space heating demand and the household are expecting their overall energy efficiency to increase from a rating of B to an A. Furthermore, in addition to helping the home lower its gas bills, the solar thermal system will also earn the homeowners a financial return. Having been installed by G-Cert sub-contractors, Howard Croker Partnerships Ltd, this Grant solar thermal system is eligible for the Domestic RHI Scheme, with regular quarterly payments set to be in place for the next seven years.

The Grant G-Cert scheme offers a solution to installers who want to install to MCS standards without formally registering with MCS themselves and takes care of all the paperwork and notifications, as well as commissioning and signing off the system for MCS approval.

Solar thermal collectors extract the heat energy from the sun and transfer this into a heating’s hot water system. Working all year round, even when the sunlight is diffused, Grant’s solar thermal systems can fulfil the hot water requirements of a home for much of the year, reducing the demand on the original heat source, such as a gas boiler in this instance. To read more about Grant’s solar thermal range, please visit: