Reality check needed: New technology doubles solar conversion efficiency

8/9/2010 11:12 AM EDT

I'm always wary of big breakthroughs, but this one seems legit and could have major implications if it works out. See any downsides?

8/9/2010 11:48 AM EDT

I don't know that I'd call it a downside, but I think it's a disappointment that power generation with such devices would require a bigger mechanical component - the efficiencies don't really come in to play unless the cell is built into a concentrator system.

The first few paragraphs of the article had me thinking about home roof-top and car-top systems, but by the end of the article, I ended up thinking more along the lines of big industrial scale power generation. That's still potentially a great breakthrough, but with a lot of caveats.

8/9/2010 1:33 PM EDT

Always surprised me how some researchers (or maybe it is writers?) can be oblivious to state of the art:

"Melosh calculates the PETE process can get to 50 percent efficiency or more under solar concentration, but if combined with a thermal conversion cycle, could reach 55 or even 60 percent - almost triple the efficiency of existing systems."

Current state of the art concentrator cells are 43+% efficient. System level efficiencies approach 30%.

Technically there are roof mount solar panels that combine standard crystalline solar cells with essentially a flat plate solar thermal connector so combined PV/Thermal exists but on a macro scale.

That said, I think it is a very interesting technology!

8/10/2010 7:13 PM EDT

As always there are many holes in the examples and logic used - a six inch wafer is used as an example, but for what ultimate power output, and what square footage of light would need to be reflected to utilize such a device?

As always a health dose of skepticism is needed, but it does seem like a very promising start!

8/11/2010 3:12 AM EDT

As per my understanding Sterling Engine technology which is age old and proven could use the Heat Energy from solar concentrators in a more efficient and simple way than this new concept. And the Stirling Engine based power plants can use alternate fuel also during the sun-down period such as the monsoon months in India

8/11/2010 2:57 PM EDT

The assistant professor said "And the materials needed to build a device to make the process work are cheap and easily available, meaning the power that comes from it will be affordable." That is exactly the same thing that was said of silicon solar cells - its cheap and abundant as sand on the beach. University researchers sometimes don't understand product manufacturing issues.

Also, the article described the device "glowing white in a vacuum". Its getting more complex and expensive already.

Obviously not enough information was provided to base an analysis on. Of course we would all love to see solar power become less expensive. But even "twice as efficient", isn't enough to meet the extravagant expectations of the public, even if it is cheap. Achieving the theoretical efficiency of solar cells or PETE devices would make application more widespread, but even that wouldn't replace coal, oil, hydro and nuclear.

8/11/2010 4:13 PM EDT

Cesium will get oxidized over time, the device have to operate in vacuum. If this is used on a large scale, Cesium price will go up significantly and the cost will go up dramatically.

8/12/2010 5:23 PM EDT

NO information of actual conversion numbers, so that makes it horizon stuff.

PETE reminds me of the Quantum Dot Solar Enhancement claims - impressive claims, but sparse on REAL data points.

Still, PETE could be a natural complement to conventional Concentrating Solar.

["...the PETE device doesn't hit peak efficiency until it is well over 200 degrees C."]

8/12/2010 5:56 PM EDT

The long-term solution to PV efficiencies may lie with a discovery probably covered here a few years ago, "black silicon" from SiOnyx, when finally brought to production it should yield significant improvements

8/14/2010 10:11 AM EDT

is it a break through?

8/20/2010 9:02 AM EDT

I've been hearing about a new breakthrough in solar technology every month or so for 20 years.

In the 80's TI announced they would product solar cells dirt cheap in a continuous strip process.

I'll believe it's real when I see it at Walmart!