The Larkfleet Group of Companies is developing a solar thermal technology under the brand name Solar Steam Limited. An experimental prototype system has been installed alongside its headquarters in Bourne, Lincolnshire.

The Technology

Currently, 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 the conventional mirrors.

The Solar Steam experimental prototype in Bourne represents the first real scale solar thermal linear concentrator using Fresnel lenses. For this reason, European and International patent have been lodged.

The market opportunity

The heat demand for the industry represents the 76% of the sector's total final energy consumption and 57% of this energy is needed at a low-medium temperatures. The potential installation capacity for CST systems is 60 GW in 2050. Solar Steam has been developed to meet this vast demand from the high-medium heating and cooling industry. The system might also be used to desalinate sea water or purify polluted water to produce clean drinking water.

Although the first prototype is has been installed in UK, the major market opportunity is likely to be in warmer countries, the MENA region for instance, where there direct radiation of the sun is higher.

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 Fresnel lenses frame rotates to track the movement of the sun through the sky during the day using a fully automatic system. The displayed version of the experimental rig consists of three modules having a total length of 13 meters (42 feet) long by 5.5 metres (18 feet) high when extended to its maximum. There are 108 Fresnel lenses installed for a total aperture area of more than 75 m2.

The Team

The solar steam system is the brainchild of engineer and inventor David Boyle, director of Solar Steel Ltd.

Recently a graduate engineer from Cranfield University has joined the project team as Knowledge Transfer Partnership Associate, founded by Innovate UK. The strategic agreement with Cranfield University has been signed in order to support the development of the Solar Steam technology with specific technical knowledge. Cranfield University is the sole UK representative on the EERA (European Energy Research Alliance) Joint Programme on CSP.

Research and Development

Research and development

The solar steam rig provides an opportunity for investigation into a new method of low carbon energy generation and is just another example of Larkfleet's commitment to innovation and energy efficiency.

Larkfleet will use this as a research and development opportunity and hopes to gain a better understanding of the technology involved and its possible uses.

This is a long-term project. Larkfleet plans to trial the technology fully over the next couple of years before coming to any conclusions about the potential for future use.

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 major developer of sustainable energy projects and a provider of energy-efficiency improvements for new and existing buildings. It is currently developing large photovoltaic (PV) 'solar farms', adding PV panels to new and existing buildings at a variety of scales, and refurbishing existing homes to reduce their carbon footprint, energy use and energy costs.

Eco House


The experimental solar steam system at Bourne sits alongside two other innovative Larkfleet projects – the Larkfleet Green Deal Eco House and the Larkfleet PassiveHouse – helping to create a local 'renewable hub' next to the company's head office.

The Green Deal Eco House demonstrates how buildings can incorporate both Green Deal and ECO funded energy saving measures in housing and commercial buildings.

The Larkfleet PassiveHouse shows how lightweight pultruded glass-reinforced plastic (GRP) composite beams and panels could revolutionise the way in which homes are built. The house is designed to be 'factory built' using modular components that can be mass produced off site and then easily installed on site with minimal labour and site waste, allowing the building to be completed in much less time than a traditionally built house.

The solar steam experiment complements the innovative, energy-efficient technologies demonstrated in these houses and further establishes Larkfleet's reputation as a leader in low carbon technologies.