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With growing concern about diminishing power resources, attention has been turning to alternative energy solutions.

Suppliers of solar thermal solutions are riding this wave of interest, but what exactly is solar thermal technology, how is it installed and how do you go about finding a reputable supplier?

There are a number of different technologies that come under the umbrella of renewable or solar solutions. In the rush to ‘go green’ there has been misunderstanding in the industry, particularly in the areas of photovoltaic (PV) and solar thermal systems. While both technologies convert the energy of the sun into a heat source, solar PV modules convert the sun’s energy into electricity with sunlight creating electricity flow through crystalline silicone cells. If a PV system is supplied, then the visible product is a bank of tiles on a roof.

With solar thermal technology, sunlight hits the absorber surface of a solar thermal collector, the surface warms and heat energy is carried away by a fluid circuit.

Solar heating systems typically consist of solar thermal collectors, a fluid system to move the heat from the collector to its point of use and a reservoir to stock the heat for subsequent use. From the exterior, the collector panel of the solar thermal system is not dissimilar to a double glazed roof window.

Solar thermal is a stylish ‘green’ solution that, even with the UK’s poor weather, can provide up to two thirds of a family’s hot water. But it is not a stand alone solution. All systems require a traditional boiler or electric immersion heating to supplement the system when there is not enough sunlight to provide the required amount of hot water.

A scientific solution

Glossy brochures can imply that it is no harder to install than a double glazed window – this is a major misconception. First, there are detailed planning considerations and solar calculations to be made. In the case of the Roth solution, for example, it is recommended that six areas are reviewed before making system design recommendations:

• Hot water utilisation

• Desired rate of solar coverage

• Location and weather conditions

• Exposure and angle of collectors

• Collector type

• Required adjustments in accordance with local conditions, such as existing storage units

From Roth’s perspective, the most important factor is hot water consumption and this should be precisely calculated based on the number of people in the household, consideration to any periodic fluctuations, such as washing a sports team’s kit every weekend, and any additional drain on hot water consumption.

These factors listed are just the tip of the iceberg when advising on the most appropriate solution. Other elements to be taken into consideration are the amount of solar energy available and degree of southern exposure.

With regard to installation, key steps for fitting flat plate collectors on a roof involve removing roof tiles, fastening rafter anchors and mounting the connector and sensor. The final stage is preparing a ventilator block.

It should be stressed that fitting a solar thermal installation is a complex process requiring specific training. Installers should commit to a manufacturer’s training programme as the full science of solar thermal technology needs to be understood. In particular, unlike standard window or plumbing projects, a solar thermal system contains glycol which needs to be carefully managed.

This is a highly technical product and even the most competent installer needs specific guidance in solar solutions. Established manufacturers including Roth are championing the importance of installer training programmes and my advice to anyone considering a move into solar thermal is to work with such a supplier.

What’s on offer?

The Roth thermal solar systems from Climate Pipework Systems Ltd range from standard installations and solar service water heating to complex installations designed to support heating systems. Co-ordinated solar collectors, roof installation kit, solar station, storage and control units provide a tailored solution to meet individual requirements. The solar thermal system can be used in combination with Roth’s heat distribution and drinking water systems.