The Larkfleet Group of Companies is developing a solar thermal technology under the brand name Solar Steam. An experimental prototype system has been tested alongside its headquarters in Bourne, Lincolnshire, and further development is now taking place in Mexico and India.

The Technology

Current concentrated solar thermal (CST) technologies use mirrors as reflectors to focus the solar radiation.

The Solar Steam technology represents an innovative system to concentrate the solar radiation. The key differentiator is the use of plastic Fresnel lenses instead of glass reflectors. Fresnel lenses are more flexible in optical design and less expensive in manufacturing when compared to conventional mirrors.

The Solar Steam experimental prototype pictured on this website was tested alongside the Larkfleet head office in Bourne, UK. It was the first real scale solar thermal linear concentrator using Fresnel lenses.

European and international patent applications have been made.

The market opportunity

The heat demand for industry represents 76 per cent of the sector's total final energy consumption and 57 per cent of this energy is needed at low or medium temperatures. The potential installation capacity for CST systems is estimated to be 60 GW in 2050.

Solar Steam has been developed to meet this vast demand from industry. The system might also be used to desalinate sea water or purify polluted water to produce clean drinking water.

Although the first prototype was installed in UK, the major market opportunity is likely to be in warmer countries where the direct radiation from the sun is higher and more consistent. .

The Prototype

The Solar Steam system consists of several rectangular Fresnel lenses which focus the sun's rays onto a metal tube filled with water. The frame carrying the Fresnel lenses rotates to track the movement of the sun through the sky during the day using a fully automatic system.

The experimental rig consisted of three modules having a total length of 13 metres (42 feet) and a height of 5.5 metres (18 feet) when extended to its maximum. There were 108 Fresnel lenses installed for a total aperture area of more than 75 m2.

Research and Development

Research and development

The experimental Solar Steam rig provided an opportunity for investigation of this new method of low carbon energy generation. It is another example of Larkfleet's commitment to innovation and energy efficiency.

Larkfleet has used this research and development opportunity to gain a better understanding of the technology involved and its possible uses. The system is now being tested in India and Mexico.

Larkfleet House

The Larkfleet Group of Companies

The Larkfleet Group of Companies is a privately-owned house building and development organisation with a strong record in creating high quality homes and communities. It specialises in building high-quality, energy-efficient housing and continually invests in research and the development of innovative new sustainable building designs, materials and construction methods.

It is also a provider of commercial and utility scale renewable energy schemes encompassing a wide range of renewables – particularly solar photovoltaic and biomass – as well as conventional energy sources.

Eco House

The current phase of testing

Larkfleet is currently involved in testing the Solar Steam concept in Mexico and India.

In Mexico Larkfleet is seeking to deliver a pre-commercial demonstration of Solar Steam at a site in Morelos in Mexico. Larkfleet will develop the pre-commercial demonstrator in collaboration with academic and industrial partners in Mexico and with the support of Queen Mary University of London. Larkfleet will contribute £160,000 to the total project budget of £800,000.

In India Larkfleet is developing a mobile version of its Solar Steam system designed to deliver renewable heat and power in remote areas of rural India. The two-year project will be delivered by Larkfleet in partnership with Cranfield University and an Indian solar collector manufacturer. The total budget is about £550,000 and Larkfleet is directly contributing £128,000 to see the project to fruition.