I followed this breathless article about advances made by DARPA and a whole bunch of other people who shouldn’t be in the energy business, throwing other people’s money at a breakthrough in the development of a gadget to make those big, expensive, inefficient solar panels obsolete, right?
Forget solar panels, optical ‘rectenna’ converts light directly to electricity
As you can imagine this is a topic likely to grab my attention over the first cuppa. And of course it goes on about the potentials…
“We could ultimately make solar cells that are twice as efficient at a cost that is ten times lower, and that is to me an opportunity to change the world in a very big way” said Baratunde Cola, an associate professor in the George W. Woodruff School of Mechanical Engineering at Georgia Tech. “As a robust, high-temperature detector, these rectennas could be a completely disruptive technology if we can get to one percent efficiency. If we can get to higher efficiencies, we could apply it to energy conversion technologies and solar energy capture.”
Wait. If you can get to one percent efficiency? Also this…
The devices operated at a range of temperatures from 5 to 77 degrees Celsius.
Which, unless I’m doing the conversion all wrong which is totally possible, means in real-people terms a temperature range of 41 to 170 degrees Fahrenheit. Which is also not a real-world temperature range.
According to the article, people have been beating their heads against this theoretically superior gadget for more than 40 years. As to efficiency,
As of December 2014, the world record for solar cell efficiency at 46% was achieved by using multi-junction concentrator solar cells, developed from collaboration efforts of Soitec, CEA-Leti, France together with Fraunhofer ISE, Germany.
Yes, Mr. and Mrs. America! Your federal government: Once again spending megawads of money on technology that completely misses the boat. The efficiency of standard-design solar panels, which you can actually buy, has improved by great leaps in the past decade as the price continues to plummet, which is why panel arrays have become so much more common while tracking mounts have gone completely out of style.
I believe, working from memory, that the efficiency of a standard solar panel is holding at about 20% at present, which is more than enough for practical use. The wholesale price is down to $0.75/watt and falling. That’s a drop of 25% in the real-market price in the last five years. Those nefarious Chinese.
Now if only our masters would stop insisting on plugging them all into an increasingly antiquated and vulnerable grid…
Also, if someone really wants to spend money, what we out here in off-grid land really need is a breakthrough in batteries. And I don’t mean lithium ion.