If you want to read about a low-tech approach to solar cells invented — and forgotten — 40 years before Bell Labs announced the first practical silicon solar cell, we can’t promise the website, Low Tech Magazine, will be available. Apparently the webserver it is on is solar-powered, and a disclaimer mentions that it sometimes goes offline.
The article by [Kris De Decker] tells of George Cove and includes a picture from 1910 of the inventor standing next to what looks suspiciously like a solar panel (the picture above is from a 1909 issue of Technical World Magazine). His first demonstration of the technology was in 1905 and there is a picture of another device from 1909 that produced 45 watts of power using 1.5 square meters with a conversion efficiency of 2.75%. That same year, a new prototype had 4.5 square meters and used its 240-watt output to charge 5 lead-acid batteries. The efficiency was about 5%.
Of course, 5% doesn’t sound so great today. But to put it in context, the original Bell solar cells in 1954 had about 6% efficiency. Oddly enough, Cove didn’t set out to build solar electric generators. He was actually trying to build a thermoelectric generator to produce electricity from a wood stove.
His design used metal plugs in an asphalt substrate. One end of the three-inch plugs would get hot while the other was meant to stay cool. The temperature difference ought to create a bit of electricity and with almost 1,000 plugs in the 1.5 square meter panel, there would be enough to do something useful.
Or so Cove thought. Some early devices generated some power when exposed to heat. But changes to the plug composition caused the device to quit working when exposed to heat. However, sunlight through a violet glass did work and worked significantly better than before. Cove couldn’t explain why, but we can see that Cove had stumbled onto a metallic semiconductor, not unlike a modern Schottky junction. The plugs were zinc and antimony — something used in modern semiconductor processing — and were capped on one end with a nickel, copper, and zinc alloy and on the other end with copper.
The article goes on to point out that simple metal solar panels could be cheaper to produce and easier to recycle. Of course, you’d need to work on getting the efficiency way up to match modern cells.
There is one disclaimer. Apparently, Cove is relatively unknown and while he has a patent issued in 1906 the patent has some misleading information in it. Add to that he was supposedly kidnapped (the police thought it was a hoax) and he spent a year in jail for stock manipulation. We don’t know how much of Cove’s story is true or not — apparently [Decker] received research from a reader, but it all sounds plausible enough.
We keep hearing about alternate solar cell materials, but silicon is still the standard to beat. Most do-it-yourself panels start with a cell, but using this low-tech method could let you produce the whole thing.
Interesting. I wonder about the cost, even at 5-10% efficiency it might work on cheap land or to make parking lot shade.
Silicon panels are already very cheap; most of the cost of an installation is in structure, inverters, interconnect, permitting, maintenence, etc.
I don’t think it’d be more economical to install 5% efficient panels even if they were basically free to build.
The most expensive component of a modern day solar system is the panel (25¢ -75¢/W) with three kissy end being huge ground mother systems and the upset end small residential systems (single panel retail pricing). Inverters are very cheap at 2.5¢ -20¢/W for the same application range. Racking os also cheap at about 5¢-25¢/W with the upper range being trackers that follow the sun and the lower end are “rail-less” residential systems. Wire is about 5¢/W.
A typical 7.6kW residential system is about 99¢/W for the hardware. There rest of the $2.70/W average install price in the US is labor and profit. Permitting is very cheap.
The cool thing about science is that you don’t have to take someone’s word for it. With an accurate description of what was built you can test and verify independently. Or, assuming it’s supposed to work, even an inaccurate or incomplete description might be a good starting point for replicating the research.
It’s was way before 1910.
https://solaredition.com/did-you-know-charles-fritts-installed-the-first-solar-panels-on-new-york-city-rooftop-in-1884/
Charles Frittes is mentioned also in the article. And it states, “It would be quite exciting to prove that relatively *high-efficiency* solar cells were invented 40 years before the development of silicon cells” – And George Cove’s solar electric generator had 5% efficiency and Frittes only 1-2%.
The selenium photovoltaic cell goes back to 1876 with William Grylls Adams and Richard Evans Day.
Looks to me a time traveller got stranded and needed to charge up their phone. :D
Or – more likely – their flux capacitor. Veeeeery slooooowly…..
Hmm ! Although I knew about selenium, this zinc antimony alloy has me intrigued as certain low cost (& a couple of natural) metallo-organic compounds just might these days be comparable band gap wise, puzzling. Thanks for posting :D
When I take a look at these plugs, I can understand how they are made for a thermal generator, but I can not see how a relevant part of the junction should be exposed to sunlight.
If you heat copper plate at a high temperature to form a red oxide layer instead of the usual blue green and put it in a jar of water with a second uncooked plate, then put it out in the sunshine, it’ll produce a current, if all be it a rather small one. Simple enough for most people to replicate.
Is this similar to a copper oxide/cupric oxide rectifier? LAthough they are normally not used in an electrolytic setup.
In some ways poor efficiency isn’t a problem, if the panels are cheap enugh you can overcome that just by putting them on enough surfaces. The problem for solar panels today which should be addressed is NOT improving efficiency, but reducing cost, so cheap panels can be put on every roof or otherwise un-useable piece of surface area.
and longevity. It doesn’t matter how cheap the installation is if you have to replace it in two years.
Solar paint.
That sounds like something out of Tom Swift.
Of course low efficiency is a problem… firstly even with the best cells you can buy you’ll still need to cover a significant portion of a roof.
If your cells are in the 1-10% efficiency range you probably don’t have enough roof for your cells. Much less be able to leave a gap where you can walk on the roof next to them.
The cell cost is low enough at this point that mounting hardware is a huge factor in installation cost… so more efficient cells reduced total system cost significantely just by reducing mounting hardware cost.
Even if you just lay the cells on the ground… you’ll save significant $ by not having to wire 2-3 times as many panels…
Bifacial could go in more places.
https://www.solarpowerworldonline.com/2018/04/what-are-bifacial-solar-modules/
Lindsay Publications once had a pamphlet on making you own solar cell, using some sort of copper oxide (Probably not recalling correctly). Now I regret not buying it.
Get it while it’s hot…
https://drive.google.com/file/d/0B33iTmoQM44UVXczaUZoaTQ3LWc/view?usp=drivesdk&resourcekey=0-dEUVa6fy5U8mhsFZEOP1Mg
“transparent metal” ? Hmmm.
I didn’t write it ;-)
Just try to help someone with their regrets.
A few nanometers of gold or silver are enough to carry current across short distances and are still “transparent”, in the 90% transmission. Alternatively, ITO (indium tin oxide) is more often used.
I didn’t read that article, but the poster did say copper oxide. Many metal oxides are transparent. Sapphire is essentially aluminium oxide and is quite transparant. Arguably, the camera protector on your cell phone is made of Scotty’s transparent aluminium.
There’s also active research right now into making it conductive, which means it could eventaully have circuitry baked right into the clear aluminum oxide “glass” sheet.
Alternatives to silicon based PV technology is intriguing. Another alternative, perovskite, is not ready for prime time but is interesting and an area of active research and development
It’s sad that this technology wasn’t developed much earlier but it’s understandable since batteries were in their infancy and there was more profit in selling coal/oil. We’re still struggling with the problem of people refusing to pay for pollution which kneecapped the green movement from day one.
That’s one view but not an accurate one for a lot of obvious reasons.
As I mentioned in my other post, electricity and motors weren’t needed to run pretty advanced factories in the 19th century. We could have easily continued using solar tubines as a source of power until solar electronics matured enough and skipped the entire pollution era.
The only “advantage” coal and oil ever had is it was much cheaper in the short term *if* you don’t make people pay for posioning the planet, and obviously, our socierty only cares about short term profits for the tiny minority.
And they were available 24/7 rain or shine, and were portable, stockpile-able, had higher power density, higher energy density, and they were readily turned into other chemicals…
Oh, and let’s not forget that manufacturing iron and steel was absolutely dependent on coke, which comes from coal.
You also have to realise that while there is some evidence the Victorians had some idea the methods of the day were not good the real science of such things doesn’t exist for decades after Victoria’s death, and real understanding of the scope of trouble from fossil fuels till maybe the 60’s if you were the scientists on the cutting edge of such research..
That is a very very long time just using the available, effective, and reliable choice that didn’t seem to have any major downside, and that is a great deal of inertia to overcome… Unfortunately that inertia also lead to huge amounts of vested interest in ignoring the reality, and a great amount of sitting on good ideas by the companies with skin in the game – its bad for their shareholders to fess up, change their business etc…
So while it is very true we COULD mostly have avoided a fossil fuel powered Industrial Revolution there is no reason to have done so at the time – hindsight is wonderful thing…
Not to mention that energy density in oil and coal is pretty hard to beat with anything except nuclear power.
Solar power goes back way before 1910 and way before electricity was used.
Think about how many machines in a modern factory are primarly driven by a motor. Before the motor was invented, factories could use a water wheel to supply power and a system of belts and gears to supply the power around the facility. These machines look incredibly similar to their modern counterparts except instead of a power court, you’ve got an axel to rotate.
As early as 1869, there were projects to use solar-fired water to turn turbines and drive factory machinery. This is the first reference I could find with a quick and lazy google search https://landartgenerator.org/blagi/archives/2004. I also remember reading about a project where they were going to use solar powered water pumps to irrigate deserts in the 19th century.
This was only abandoned when oil was discovered and turned out to be cheaper and more portable. Nobody gave a damn about the environmental damage or huge political issues when there were big profits to be made, so oil and coal-fired electricty took over.
The industrial revolution started when the societies started using steam power instead of water wheels, because it allowed the industries to move down from the hills and into the cities, which was a logistics advantage in a time when goods and raw materials had to be carted by mule. Supply couldn’t meet demand until there was a portable power source that could bring the industry to where the consumers were, and the only thing people had was wood.
The demand for wood to make charcoal for iron smelting grew to the point that people couldn’t build ships for a lack of timber and they were quickly approaching the point of burning all the forests in Europe flat for want of fuel. The discovery of coal, and more importantly the discovery that you could distill it into coke, saved the world from our first energy and environmental crisis.
Water wheels, windmills and “solar turbines” were invented alright, but they simply could not rise up to the task.
One might say that the industrial revolution was kicked off by the need to pump water out of deep coal mines, and a coal powered steam engine seemed like the perfect tool.
You might say that, but actually at the time the coal was near the surface, and the first use for steam-powered mine pumping engines was in the ore mines in the south of England, which were deeper, near the sea, and flooded more.
It was only later that coal mines in the UK went very deep underground.
Solar panels, electric cars and Teddy Roosevelt, the 19th century was a hell of a time.
I would love the hackaday community to experiment with solar cells that would work adequately in a much higher radiation environment, dry, with a thin atmosphere. And which could be made from ‘found objects’ such as sheets of nickel/iron with the minimum of manufacturing required. In other words, of course, could a robot dispatched to the moon or mars easily assemble moderately effective solar cells from iron/nickel rich rocks or meteor fragments. Although most engineering is more difficult in space, I feel photo-voltaics could be the exception.
I’m currently trying to replicate this. However the zinc antimony alloy is a pain, as the resulting metal is very brittle. So far I don’t see any effect unfortunately but I’m trying to optimize the alloy.
I’d love to know more, do you have any details?