Dial back 10 years, the Renewable Heat Incentive (RHI) was launching and solar thermal systems were popping up on roofs throughout the UK. Following a peak in 2014, this initial interest petered out with people more attracted by the returns offered by PV, effectively muscling solar thermal off the roof. 

For many homes, however, solar thermal offers a quick way to reduce fuel bills, fitting well with other technologies and working on most buildings that get a good amount a sunlight. With new developments that combine solar thermal with other technologies it’s time to take another look at this great way of producing domestic hot water.

Back to basics

A well designed typical solar thermal system in the UK covers around 40% - 70% of the total hot water consumption. During the summer, solar thermal panels can produce almost all of the hot water demand. In spring and autumn, by pre-heating a water system, solar still contributes to reducing the amount of energy needed.

Solar thermal collectors come in two types – flat plate, which look similar to the photovoltaic system - and evacuated tube collectors. Each has their own merits but flat plate collectors are more widely used in the UK. 

Future Homes Standard

The recent Future Homes Standard update has a target to reduce new build carbon emissions by 75 – 80% by 2025, with an interim reduction of 31% by June 2022. To achieve these bold ambitions, we need all hands to the pump (or roof), no renewable should be discounted and many homes will benefit from a combination of technologies.

In towns and cities that currently rely on gas, solar thermal can significantly cut carbon footprints and meet the Future Homes Standard’s other aim - tackling fuel poverty. Householders pay around £379 a year on energy, but a house with a gas boiler and solar panels will pay closer to £168 – a significant saving. If and when the hydrogen network is introduced, solar thermal will continue to work well alongside it.

For existing building services installers looking to take advantage of this marketplace, upskilling into solar makes sense – the technology has national appeal to both urban and rural properties. At the moment, funded training is available, covering a significant amount of the cost of the training and MCS certification.

Evolving technology

From aesthetics to technology, solar thermal is evolving. The latest solar thermal collectors are inconspicuous and more likely to be fully integrated into a roof in new build properties.

And, unlike its electrical cousin (Solar PV) Solar thermal doesn’t suffer in the same way when there is the potential for shading from local trees or buildings making it possible to fit in more situations. 

Green for good

As the peaks and troughs of the RHI taught us, a green future solely influenced by funding incentives is not sustainable (at the time of writing the Green Homes Grant is on shaky ground.) We need to be making renewable choices wherever we can, changing the ingrained culture of how we heat and light our buildings, and encouraging homeowners to see renewables as a first choice, an easy choice and a cost-effective choice.

Solar thermal can provide a great starting point, one that doesn’t have to disrupt a property or existing heating system, but will make a significant impact on fuel bills. And, as it continues to develop – combined with storage systems and complementary technologies such as air source heat pumps – the future for solar looks bright; nature’s ultimate power source.