Commercial solar thermal applications

Solar thermal heat can be used in processes that require large amounts of water to be heated from cold to warm. For example water from a well or the mains supply at a temperature of 15ºC can easily be heated to temperatures of 40-50ºC and higher. Although an auxiliary source of heat will  be required in winter and on dull days throughout the year, solar thermal can make significant fuel savings, depending on the desired temperatures. Where water has to be heated to higher temperatures, such as 80ºC, solar thermal can still contribute. Here we use evacuated tube systems which perform better at higher water temperatures than flat plates due to their lower heat losses at high temperatures. It is quite possible to heat water to 80º on a sunny day in summer, but lower temperatures will be achieved in winter and on cloudy days.

Commercial solar thermal installations are now eligible for regular support from the Renewable Heat Incentive at a rate of 8.5 p per kilowatt-hour, paid quarterly for 20 years. When combined with the cost saving on the fuel, this makes solar thermal applications a very attractive proposition financially.

Residential accommodation - care homes - hospitals - schools

In buildings with common hot water provision a solar thermal system can pre-heat the incoming cold mains, with a contribution of up  to 70% from solar averaged over the entire year. 

Left, a solar installation for the SureStart children's centre in Bradford on Avon with inset, the final result set into the roof.

Hotels and restaurants

Places that prepare food are an ideal application for solar thermal, as they use large amounts of hot water are needed throughout the day.

Our clients include a McDonalds Drive-Thru restaurant in the southwest, where a large solar array is situated on the central part of the roof, hidden from public view by a tiled parapet.

Breweries

In breweries solar thermal can pre-heat the water used for wash-down. The system can be designed to provide marginal space heating in winter as a means of frost protection.

(Right) Soltrac's solar test facility at the Keystone Brewery in Berwick St Leonard, Wiltshire, supplies hot water to this award-winning brewery of real ale.

Camp sites

Hot water is needed throughout the day for showers and washing. Demand is greatest in the summer when most visitors are on site. The camp sites we've seen use expensive LPG gas as their heating source. Like farms (below), most camp sites are not on the main gas network and so cannot take advantage of much the cheapest (fossil) fuel in the UK.

Farm dairies

In dairies solar thermal can pre-heat the water used for pipe cleaning and wash-down. This is a significant cost both in financial and environmental terms, since most farms uses mains electricity to heat large amounts of water up to 80–90ºC twice a day to meet modern hygiene standards. Our solar installation at Bridzor Farm in Wiltshire heats a 1000 litres of water up to 78º on a sunny day in summer, saving thousands of pounds in electric bills each year.

 

In our experience, solar thermal is less suitable for office environments, where the hot water need is not sufficient to justify a dedicated solar system. Also, many modern buildings waste a lot of heat from coolers and air conditioners, and this can be used to pre-heat the water.