Seven Spires takes stake of CPV startup Circadian Solar

Coventry, UK-based Circadian Solar said today it raised £2 million ($3.3 million) from Seven Spire Investments to speed commercialization of its concentrated photovoltaic technology.

Privately held Circadian, which changed its name from AdvanceSis in July, uses a fresnel lens to concentrate sunlight onto gallium arsenide multi-junction solar cells, aided by the company's proprietary high-precision solar tracker unit.

In all, Oxford-based Seven Spire Investments plans to invest £8 million in Circadian during the next three years. Today's £2 million funding represents the second tranche of that investment, the companies said.

The funding is expected to allow Circadian to complete a commercial-scale demonstration and test system. Circadian plans to send a 1-kilowatt unit to a Mediterranean test site this month, with a commercial-scale system to follow before the end of 2009.

Circadian also plans to use the money to invest in a joint venture aimed at reducing the cost of high-performance solar cell devices.

The biggest solar deal of the year so far went to California-based SolFocus, which raised nearly $78 million in a Series C round for its CPV technology (see SolFocus closes $77.6M round, readies for manufacturing ramp).

Circadian says its technology has applications in on- and off-grid solar, such as remote telecoms power supply, decentralized power in rural areas and refrigeration.The company says it incorporated manufacturing techniques and design procedures used in the automotive industry to build the systems.

Circadian said the systems, which boast a 25-year lifespan, overcome problems that other CPV developers face with inadequate wind resistance, cable management and frequent service requirements.

The company has more than 20 employees in the UK and an unspecified number elsewhere in Europe.

Seven Spires invests up to £5 million per year in UK-based private technology companies. The firm participated in a £5.1 million round raised by Metalysis in May with Environmental Technologies Fund, 3i, Chord Capital and Cody Gate Ventures (see Energy efficiency rules week's cleantech roost).

Metalysis, which develops technology for the energy-efficient manufacturing of alloys, owns the global intellectual property and commercial exploitation rights to the Fray-Farthing-Chen Cambridge Process, which it says enables a cheaper, less capital intensive and environmentally more attractive production route to high value metals and alloys compared to conventional technologies.