Solar Power at Half the Cost (Concentrating PV, MIT Tech. Rev.)

[jpak]

http://www.technologyreview.com/Energy/18718/

A new mechanism for focusing light on small areas of photovoltaic material could make solar power in residential and commercial applications cheaper than electricity from the grid in most markets in the next few years. Initial systems, which can be made at half the cost of conventional solar panels, are set to start shipping later this year, says Brad Hines, CTO and founder of Soliant Energy, a startup based in Pasadena, CA, that has developed the new modules.

Concentrating sunlight with mirrors or lenses on a small area cuts the costs of solar power in part by reducing the amount of expensive photovoltaic material needed. But while concentrated solar photovoltaic systems are attractive for large-scale, ground-based solar farms for utilities, conventional designs are difficult to mount on rooftops, where most residential and commercial customers have space for solar panels. The systems are typically large and heavy, and they're mounted on posts so that they can move to track the sun, which makes them more vulnerable to gusts of wind than ordinary flat solar panels are.

Soliant has designed a solar concentrator that tracks the sun throughout the day but is lighter and not pole-mounted. The system fits in a rectangular frame and is mounted to the roof with the same hardware that's used for conventional flat solar panels. Yet the devices will likely cost half as much as a conventional solar panel, says Hines. A second-generation design, which concentrates light more and uses better photovoltaics, could cost a quarter as much. He says that a more advanced design should be ready by 2010.

The Soliant design combines both lenses and mirrors to create a more compact system. Each module is made of rows of aluminum troughs, each about the width and depth of a gutter. These troughs are mounted inside a rectangular frame and can tilt in unison from side to side to follow the sun. Each trough is enclosed on top with a clear acrylic lid. Inside each trough, a strip of silicon photovoltaic material runs along the bottom. As light enters, some of it reflects off the inside surface of the trough and reaches the strip of silicon. The rest of the incoming light is focused on the strip by a lens incorporated into the acrylic lid.

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[NJCher]

1. pics

there are some good explanatory pics at the web site.



Cher

[One_Life_To_Give]

2. $2.50/Watt Can't wait!

AT that price I think I can talk the Wife into letting me put a KW on the roof.

[skids]

3. Soliant is interesting in this respect...

...most of the solar concentrator folks are targeting a reduced price point, some even below Soliant's. They do this simply by concentrating onto commodity solar cells, which can take more sunlight than they get in a flat 1-sun module.

In addition to trying to fit things into a self-contained,self-powered system in the same profile as current panels these guys have one other niche that is not as readily noted: they plan to use the triple junction cells which have higher efficiency when dealing with concentrated sunlight. They think they can get the power density of the units up above that of mono-Si, which would make them the most effective system available for those who are trying to squeeze as much power onto a small roof as they can. That is, if they can actually get a significant efficiency gain at their 2-3 sun concentration level. They seem to think they can.

Each of the companies has their target niche -- some will be thinner, some lighter weight, some better for BIPV and in-window use, some with better wind/stability/installation profiles, some more suitable to flat top roofs. A few of the things Soliant says set them apart actually do not -- other companies do low concentration and panel-profile units too -- but I don't think the others plan for high power density. So another company may beat them eventually in dollar-per-watt, but they'll still be leaders in at least one desirable spec.

Now all that of course hinges on whether their outsourced fabrication plans come together in a timely and efficient fashion. They have MIT helping them figure out how to scale the product and take advantage of mass production, but until you see quantity modules ship, there are good reasons to be skeptical of all the companies.

When a solar cell producer buys into one, though, that's a good sign, and when a concentrator company buys a lot of solar cells, that's also a good sign that products are finally going to start moving. About damn time.

[philb]

4. Do they not plan on commercilizing these until 2010? or are some ot these

entering the market place sooner?