My father and I built a solar powered dog house heater in the 80s. We got the idea and plans from a Detroit area newspaper. The “cell” was simply plywood painted black behind a piece of glass with room in between for air movement. It successfully raised a fully sealed box (perhaps almost 1sq meter) to 40 deg C in the dead of Michigan winter. It also got me a blue ribbon at the science fair. I’ve been intrigued by solar power ever since, but only in terms of tracking the science progress.
This is pretty cool on its own but the fact you did it before the internet using a newspaper is very interesting. I really struggle to imagine how I'd do anything without looking online.
There used to be bookstores and magazine shops. I don't quite mean to say these no longer exist outside of airport waiting areas but they were ubiquitous. Libraries were a source of knowledge rather than a place to get free wifi. Wikipedia's predecessor came as a shelf of books.
This sounds snarky but I don't mean it as such. It's what was available and how much knowledge was passed around. It wasn't hard to learn about even esoteric things if you had a good library. It was hard to find more than one such book though, so there wasn't as much opportunity for expansion of knowledge by comparing approaches.
I like the internet age better though it has become more challenging to separate fact and fiction. The library didn't have too many fake science books.
> The library didn't have too many fake science books.
As a kid, I found the UFO section of the library and read all kinds of interesting and almost certainly not true things. It was conveniently next to the programming books ..
Pre-internet people subscribed to specialized periodicals. Home Power and Mother Earth News were two. Both were filled with case studies and DIY projects and the back pages had "send $5 for plans to build your own low-head hydro." I'm sure there were more publications (Stewart Brand's publications come to mind, Whole Earth Catalog and CoEvolution Quarterly for two.) The archives of Home Power (1987 - 2018) are here: https://www.homepower.com/
Popular Mechanics and other "Popular xxx" magazines are also examples. If you were lucky your local library subscribed so you could read them there (hopefully people hadn't stolen the issues or ripped pages out.)
Ay one level, obtaining knowledge was different. You went to libraries--assuming you had access to a good university or city one--and good bookstores, which were also somewhat limited outside of major cities. You called people or wrote them letters. Etc.
It was however also just harder and more limited. I definitely had projects in school that required looking through the library stacks and probably ended up with more "winging it" and depending on one or two old sources than would be the case today.
Or if you couldn't find it in a library, you could call a librarian: company, city, university, or otherwise.
I enjoyed the film Desk Set. Katherine Hepburn is one of those librarians, working at a pseudo-NBC company in the 50s. (As a special bonus, it features early movie mainframe hijinks.)
A little on a tangent, but I've been thinking that it might be valuable to keep this offline knowledge infra around for backup, afaik properly stored book has lifespan that is still an order of magnitute longer than any digital storage.
On the one hand, barring natural disaster/fire/water leaks/etc., your library book will last a good long time--at least until the library gets rid of it because they need the space and no one's checked it out recently. On the other hand, even with inter-library loan, it's not super-accessible especially if it's in, say, a private university library. And if something does happen to it, it's gone.
On the other hand, a single digital copy won't last as long. But subject to a lot of factors and caveats, copies of that digital artifact can last indefinitely.
Yes, trade-offs all the way down :)
Physical damage of the nature you described affects many forms of digital storage too, though I doubt vermins will find them very palatable. And there could be many copies of a book, to your second point. There is also the question of the specialized equipment needed to read the digital media. As I said, trade offs. I try to maintain a personal book library just because I was an avid reader growing up, in the pre-internet days, and I don't want to see the future generations go pure digital, but maybe it is inevitable.
I did something similar with a solar oven. Painted a mason jar black and then used aluminum foil to build a concave reflector. It worked ok, but I was able to get water above the pasteurization point (160* F).
Young me went to a solar exhibition at Brookhaven National Labs around 1978 or so. They had an electric car (maybe the Electrovette?), photo electric panels and outside someone showing how to make a forced air solar heater. It was an insulated box with a glass or plexiglass window to allow light in. Inside was an array of cut up soda cans, all painted black. A port for air inlet and a port for outlet and voila.
[I'm pretty sure this was in BNL's old graphite research reactor building, which was open for tourists. I've since learned that this was an air-cooled reactor like the one in the famous UK Windscale accident, and that it has now been completely disassembled.]
Solar was big then- I remember a talk about it at the local library also. People were making parabolic solar hot-dog cookers.
Why is it never surprising when we hear stories like how Edison bought a thermoelectric generator company (Clamonds’s Improved Thermopile) and ceased development.
How much human progress is hampered by the desire of some to profit, no matter the cost to the world?
> Purportedly, the unnamed inventor of flexible glass (vitrum flexile) brought a drinking bowl made of the material before Tiberius Caesar. The bowl was put through a test to break it, but it merely dented, rather than shattering. The inventor repaired the bowl easily with a small hammer, according to Petronius. After the inventor swore that he was the only man alive who knew the manufacturing technique, Tiberius had the man executed. He feared that the glass would devalue gold and silver, since the material might be more valuable.
WWII would have looked very different, especially the aircraft. Naval warfare would have looked nothing like it did. Well, maybe naval boilers wouldn't be counted as ICE, but even if you allow for that it likely means no oil based infrastructure so everybody is still shoveling coal. Even that relatively small change makes a big difference.
If it were really that valuable to human progress wouldn't another company or competitor to Clamonds’s Improved Thermopile become extremely profitable and valulable?
Maybe? But sometimes people don’t see “obvious wins” for a very long time.
Look at Musk’s electric car story: there were a variety of electric cars that companies killed off (like the EV1) years earlier than the Tesla was released. It’s unclear if anyone who had the capital would have seriously entered the space if Tesla as a company did not exist. Maybe we’d be exactly as far along, but there’s a good chance the lack of “electric car infrastructure” and internal company incentives would basically keep anyone from going far enough before killing their project.
When the path to profit is only a short journey from where we are now, you’re right that some other company will probably adopt it. But add two or three hard steps that they need to overcome first, and it’s pretty common for human progress to stagnate in a local maxima for a long time.
Unfortunately no, there’s no law of nature which says companies/competitors will appear to serve this kind of function.
Mostly bc short term profit maximization can be thought of as a greedy optimization which is blind to long term gains. This is why the tragedy of the commons happens
>If it were really that valuable to human progress
The issue here is resting that value judgment on a small number of people (in this example, one person: Edison) to determine if it's valuable to human progress. They could be malicious or simply wrong about their estimation.
But also, no, markets aren't efficient, so they won't necessarily be correct on value-for-human-progress.
It might have been patented. By the time the patent runs out the alternatives have become standardized and refined enough that the original can't compete.
I put some used PV panels on my shed's roof and wired them up to the bottom element of my electric water heater. This cut my household electric use in half. Not connected to the grid so no expensive permits needed.
Yeah I wish there was more of this happening. BTW what happens when your water is fully hot and the sun is shining - does that panel detect there is no load so doesn't generate?
There is no thermostat for the PV panels. The summer power output of the panels comes into equilibrium with the heat loss of the tank at 80-85C. I did add a 93C thermal fuse to augment the safety of the PTV value.
I have a mixing valve on the output of the water heater to mix with cold down to about 50C. This lets you get around 2x the nameplate capacity of hot water out of the tank so there is enough to bridge a cloudy day.
To get the full capacity of the panels, it necessary to choose a water heater element that matches the source impedance(Vmpp/Immp) of the solar panel array.
> Instead of using 4,500 watts for 45 minutes (.75 hours), a hybrid hot water heat pump uses 350 watts for 3 hours.
I saw video of a guy installing one in his off grid house. He was mostly stoked with it because it only drew about 300W. But had a problem because it would do a check of the heating elements on startup which would crowbar his inverter. He fixed that by installing lower wattage elements.
In north america both terminals of the heating element are galvanically isolated from the tank, so this is not an issue if the wiring is installed with due care.
In countries like brazil and germany that allow "bare wire" heating elements you might have trouble with the tank lining plating onto the element or visa versa.
The materials cost was about $1400, half of that is the panels the rest is wire, conduit, brackets, etc. A solar permit in my area costs $1200+ . The high permit costs would make a system this small uneconomic. Local codes vary but in my jurisdiction I could avoid need for permit by putting the panels on my shed instead of my house and using the power for the water heater instead of connecting to the grid.
The payback is 3-6 years depending on what ratio of peak/off-peak power pricing you assume.
With these figures they could easily rely on used solar panels and batteries, therefore adding nothing to the environmental cost of building new ones and reducing the impact of recycling them by increasing their active life. Gradual repurposing of used cells and batteries to less demanding uses should be always considered before sending them to recycling.
I do this all time with normal batteries, including non rechargeable ones such as alkalines: a battery that can't supply a toy with motors anymore will likely work in a small radio, and the one which is becoming too weak to supply a radio can work for some months in a TV remote.
I realize this is almost completely off-topic for the article, but I really like the way this website communicates the server's charge levels with color and indicators as a percent of the page's visible area.
It's a cute approach, but perovskite solar cells can probably do much better. Perovskite solar cells can be made at close to room temperature, use relatively common elements, and can be made fairly thin. The current efficiency record for perovskite solar cells is 25.6%[0].
The purpose of the article was to explore diy manufacturing of pv cells. I don't think this korean/swiss collaboration on high efficiency perovskite solar cells is within the reach of your backyard fabricator.
Perovskite cell manufacturing is quite DIYable. There's been several experiments (lab-scale, not industry-scale) with making the lead-based perovskite film from waste with very minimal equipment. The main problem is toxicity, both to people handling it and to environment if disposed of improperly. Example: https://www.youtube.com/watch?v=oQ2bz6jlbz0
Perovskites break down when exposed to moisture, so while I do think you could DIY a solar cell pretty easily, it wouldn't last long. There are ways around the moisture problem, but they're not so easily DIYable. "In particular, water promotes fast decomposition, leading to a drastic decrease in device performance." [0]
But why not more microscale concentrated solar especially for DIY? For example parabolic mirror from a thin steel plate, or just a bended steel plate, (both in themselves >90% efficient?) -> liquid salt -> steam boiler system -> DC motor seems necessarily to me be a) more efficient b) cheaper to build than perovskite and also c) the skill - level required is very low tech (except the optional liquid salt phase).
This is quite fascinating, if true. Having studied solar photovoltaics fairly extensively in both undergrad and grad school, I'm a bit skeptical that he achieved such efficiency with such a simple design, but it's not completely impossible.
It's important to note, though, that most of the cost of present day polysilicon solar cells comes not from the semiconductor device and contacts, but from the module and supporting electronics. So trading cell efficiency for cost will actually degrade overall installation cost per watt (since you'll need more of the more expensive parts), AND increase the amount of land required.
I think the "interesting" part of this is that you could generate useful amounts of electricity with panels that could be made and repaired/maintained/recycled in a very DIY fashion. They would definitely be worse than commercial Si panels in every other way, but when a ~400W panel on my roof breaks, it's probably going to wind up in a landfill rather than me troubleshooting and fixing it. A 5%-efficient panel that was very DIY-friendly would be pretty neat.
If not for EVA encapsulation, silicon solar cells can be "recycled" by a 30 minute forming gas anneal at 400C. I don't know if all panels have EVA encapsulation or not. If so, then I doubt these ZnSb would degrade any better without a similar encapsulation.
This is such a simple thing to test and write up as a business plan. My oven doesn't go to 500C, but from the description it does sound like a simple factory process could produce these.
The title made me think of my final first year chemistry lab where we made dye-sensitized solar cells from raspberries. It was an incredibly low-tech process aside from the conductive oxide-coated glass slides used as the electrodes. I'd love to see an in-depth guide on this solar panel design.
The person who was in touch with the author of the article, Philip Pesavento, appears to have a background in electrical systems that would be relevant to the material (i.e. he's not a crank)...
The website is powered entirely by solar and is currently consuming 2.44 watts. With that massive power consumption they are probably mining bitcoin too.
