News on the Rise of Solar Concentrator Technologies in Energy Tech

I always try and keep an eye out on what other investors and analysts think is hot. We have been chronicling on Cleantechblog the rise in energy tech / cleantech venture capital investment in solar for some time. This has been driven primarily due to an exploding public capital markets in solar, creating attractive exit returns.

Well the “new” news in energy tech venture investing seems to be solar concentrators. Opportunities in solar collectors / concentrators have been coming across my desk in increasing numbers lately.

Solar concentrators basically put a lens (called a Fresnel lens) on top the solar cells, focusing sunlight onto a standard photovoltaic cell and making it tremendously more efficient. Not too different from using a magnifying glass and the sun to start a fire. However, concentrators tend to do better when the light source is a single point, and pointed straight at the cell.

There are literally hundreds of design concepts in the academic and commercial literature on ways to achieve this, but that’s the basic concept.

The advantages:
  • Solar concentrators at heart are attractive because they reduce the amount of cells needed to deliver the same level of power output (and thereby the cost)
  • In addition, many solar concentrators are trying to use a much larger part of the light spectrum to generate electricity.
  • They also deliver the promise of low capital cost for the manufacturing facilities (equipment to make concentrators is not as expensive as that to make cells on a per watt basis).
  • One of the biggest advantages, I think, is the potential to make much larger module sizes with concentrators than straight PV cells. This has long been a big knock in the solar industry.

The knock on solar concentrators, however, has proven tough to get over so far:

  • To be effective, they tend to need very high efficiency cells (most people are saying 25%+ efficient).
  • To be economic, they tend to need some sun tracking capability – which is tricky to do for systems designed to last 20 years.

However, advances in new high efficiency cells for the aerospace industry, long the province of niche solar players like Spectralab, are expanding the potential.

Some of the recent venture capital deals in solar concentrators include:

Energy Innovations raised $16.5 mm in 2005 for their Sunflower module array of concentrating mirrors that track the sun. Lead investor was Mohr Davidow.

Prism Solar raised a seed round for a holographic planar concentrator which passively tracks the sun and spectrally selects desirable wavelengths.

Whitfield Solar in the UK received a funding round in 2005 including Carbon Trust for its solar concentrator technology.

And given the level of new solar concentrator deals heading to venture forums like the Cleantech Venture Network, IBF and Clean Edge’s Cleantech Investment Conference, and NREL’s Industry Growth Forum, we are likely to see a lot more.

One of my favorite ones that hasn’t gotten major funding, but has been building full scale systems for several years is Solar Systems in Australia,

A few other solar concentrator energy news tidbits:

The National Renewable Energy Laboratory is sponsoring a Conference on Solar Concentrators for the Generation of Electricity or Hydrogen in May in Scottsdale with Arizona Public Service, one of the leading renewable utilities in the country.

Blog world is picking up the trend:

The Energy Blog just did a post on one that uses a flat Fresnel lens to collect the sun’s energy and focus it onto a copper block, Energy Blog Solar Concentrator Tech Post.

Future Pundit did an article on solar concentrators last July, Future Pundit Solar Concentrator News

EV World did a blurb on solar concentrators in July, EV World News Post

If you have any other concentrators, news, deals, or blogs, post them here in the comments section.

Despite all this, solar concentrators remain a minute portion of new solar installations, let alone the total installed base. So I guess the big question, still unanswered, is whether solar concentrators can be the elusive technology to take solar into 1:1 competition with grid power. The last solar technology class to wear that mantle, thin film, has yet to overtake the crystalline silicon market in cost or market share.

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