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.[4]
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.
Yes indeed… better batteries for everything. I’ve just about stopped buying battery operated things. Plug in or hand operated for me, if possible. I’ve spent a fortune for batteries over the last many years, and even the lithium kind are not that much better in the long run.
What you said about batteries!!! We just replaced our 12 6v batteries to the tune of $3,000.00, and that was shopping around. Batteries, in our experience, only last for 5-8 years. Our panels are 20 years old and are still functioning well, although for what we paid, back in the day, for top of the line 75 watt panels, you can now get 200 watt ones. There are advances, just not what you’d expect by this day and age.
[rant] And with all the hype about the environment and climate change and tree hugging stuff and energy conservation, it came as a heck of a surprise to find out that it’s nearly impossible to get a mortgage on an off-grid home. Thankfully, the realtor selling our forest home did find ONE lender(out of how many hundred out there?) willing to give the buyer a mortgage on the house, but boy what hoops we’re having to jump thru to prove that it’s an actual livable house with all the permits, inspections, bells and whistles of bureaucratic compliance. [/rant]
PS. How are you feeling today?
The prices for solar may have come down in the States but up here North of Disorder it’s still expensive.
The DARPA thing isn’t as big a drawback as you may think. One way around the temp issue is to have the Optical Rectenna mounted inside a roof under glass to keep the unit within the temp range. The glass could have an automobile like defroster/defogger to keep snow/ice off. The downside would be a power drain from the batteries.
Speaking of batteries… I had a bit of hope when Tesla made that big announcement about the Power Wall home battery. I was even going to get some solar panels to charge the damn things. Looking deeper into it I found the return on investment wasn’t worth the cost of admission. I soooooo want to get off the grid energy wise but the up front cost and the logistics are a killer.
“I soooooo want to get off the grid energy wise but the up front cost and the logistics are a killer.” It sucks because it leaves us at the mercy of the utilities, but so far the very best “battery” in existence is the grid itself. Thus the invention of the grid-tie inverter.
“Yes, Mr. and Mrs. America! Your federal government: Once again spending megawads of money on technology that completely misses the boat.”
I for one am more bemused/annoyed at fed.gov for spending buttloads of $$$ back in the day for ‘rural electrification’ (Read: forcing midwest farmers to tear down their perfectly functional wind-gennies and hook up to the grid), only to turn around just a few decades later and spend even more money trying to entice people to erect ‘alternative energy’ producing equipment (including the same damn wind-gennies they paid people to tear out to begin with!).
As for better batteries…
*cough*
https://en.wikipedia.org/wiki/Nickel%E2%80%93iron_battery
*cough*
Is “rectenna” a portmanteau word? Sounds…painful.