ozarque ([info]ozarque) wrote,
@ 2007-11-15 08:28:00
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Personal note; links I meant to recommend but couldn't...
I went to Google this morning looking for some links to articles about the Nanosolar Powersheet -- which was designated as "Innovation of the Year" in the current issue of Popular Science -- and to articles about Frank Pringle's microwave process for turning trash into oil, also discussed in that issue. There were links, but every one of them I clicked on sent my browser into frenzied tremors and discombobulations, ending with a total crash. Apparently there are very large numbers of people all trying to read those same articles ... something I should have guessed when I saw that the sites offering information included BoingBoing and Digg and TechnoPundit. Which should mean that all of you already have heard lots about Nanosolar Powersheets and Frank Pringle's new gizmo, without any need for nudgings from me.

Very interesting and encouraging developments. I think. If you have comments, I'd be interested.

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[info]pgdudda
2007-11-15 04:24 pm UTC (link)
The solar stuff is very interesting indeed, as well as News To Me™. So rest assured that you are not the Last Person In LJ to learn of this. *grin*

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some solar-power results (1 of 2)
[info]dteleki
2007-11-29 02:42 am UTC (link)
Thank you for bringing this up, because it was News To Me also. After a couple hours of research, I find myself cautiously optimistic about the Nanosolar Powersheet, but also curiously unimpressed. "Unimpressed" partly because the Nanosolar Powersheet closely resembles a "Douglas-Martin Sunscreen" right out of a Golden-Age Robert Heinlein story (call this the "oh, THAT" effect; and partly because I've heard claims like this before, and not just once either (I'm thinking especially about the extravagant touting of "ovonics"-based solar cells here).

The real problems here involve, basically, running the numbers. I haven't found information that I can really trust any more confidently than back-of-the-envelope calculations, because there always seem to be some crucial assumptions left unexplained. Here are some ideas I've put together from various places that you might find enlightening, or at least amusing.

* My electricity consumption appears to average out to about 570 watts. That is, my ENTIRE LIFE is 570 Watts, day in, day out; averaging out day vs. night, air conditioning vs. fans vs. nothing, and so on. Supposedly the average American household averages out to about 1300 watts. Going month by month, my maximum is 1200 watts in July when the air conditioners are going. To find your own average, look at your electric bill for "kWh consumed", divide by the number of days on the bill, then divide by 24 (i.e. 24 hours per day), then multiply by 1000 (watts in a kilowatt). Doing this for a year's worth of electric bills shows how your electricity consumption goes up and down.

* Because I live in an apartment, there's a lot that the landlord is paying for (and including in my monthly rent) that I don't know the prices and quantities of. Natural gas for heating, for the stove, for the clothes dryers; electricity for hallway lights, exterior lights, building systems. And gasoline for cars and buses, or power for subways and el trains, isn't included here at all.

* If my calculations are right, then the roof over my 1000-square-foot apartment could generate ALL of my electricity and about 30% more. (I live on the top floor.) To put it another way, if you covered the entire roof with solar cells, they could power everybody in the top floor and 30% of the next floor -- which is unfortunate, because it's a 9-story building. High-rise buildings aren't going to be self-supporting for electricity, unless efficiencies go up a LOT. One-story single-family homes have a good chance at energy-self-sufficiency, though. Part of the problem is that here in Chicago, the days are both very short AND very cloudy in the winter.

* There appears to be about a three or four year payback period to recover the initial cost of Powersheets, which is well within reason but not spectacular. (THIS calculation is based on several very dubious assumptions, for lack of any really hard information.) The price per square foot of Nanosolar Powersheets appears to be about the same as for attractive hardwood floors; that is, the price per square foot of Powersheets appears to be more or less within the range of ordinary building materials, as opposed to a hopeless price like the price per square foot of flat-screen TV's. Because the price per square foot of Powersheets is a building-material-like price, it starts to make sense to think in terms of constructing a new building with its roof covered entirely with Powersheets.

* When I visit my father for Christmas, I plan on going through his utility bills to learn how much of HIS life could conceivably be powered by Nanosolar Powersheets. He's more like an average American than I am, plus I can go over his electricity AND gas AND gasoline for the car. The result that I expect that I will end up with: his electricity is covered, his heating and cooling are covered, everything in life is covered EXCEPT for the car (and the car will be awfully big). I'm also planning to calculate just how much power could be generated by solar panels on the roof of a car (probably nowhere near enough), and just how many calories could be photosynthesized by a chloroplast-filled human being sunning on a beach (probably not enough to sustain life above the coma level).



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some solar-power results (2 of 2)
[info]dteleki
2007-11-29 02:45 am UTC (link)
* The 75-horsepower gasoline engine of a Toyota Prius hybrid car is connected to a 50,000 watt electric generator. That gives some idea of just how much energy a car consumes. 75 horsepower is a very modest engine by today's standards. However, one legendary high-performance luxury car, the Citroen DS, made do with an engine of similar size; the argument was that the DS never really needed to accelerate quickly, because once it was moving at 80 or 90 miles per hour, there was never any need for it to slow down, and it could cruise for hours. It could even run over potholes and railroad tracks without slowing down, because its ultra-powerful suspension completely absorbed the shock that would jolt or even damage less exalted vehicles. So, "low" horsepower in a car's engine is not necessarily a fatal fault, not even in a luxury car.

* I found this ominous note in the Wikipedia article on Solar Cell: "Approximately 70% of Indium currently produced is used by the flat-screen monitor industry. Some investors in solar technology worry that production of CIGS cells will be limited by the availability of indium. Producing 2 GW of CIGS cells (roughly the amount of silicon cells produced in 2006) would use about 10% of the indium produced in 2004. For comparison, silicon solar cells used up 33% of the world's electronic grade silicon production in 2006! Nanosolar claims to waste only 5% of the indium it uses."

* There's a solar-power calculator that shows how much electricity can be generated in various locations, taking into account day vs. night, and cloudy days. One of the locations shown is Fort Smith, Arkansas. If you leave all the fields at their default values, it assumes a standard-sized solar panel mounted permanently on an angled stand, WITHOUT any motors to aim it at the sun. The standard "4 kilowatt" panel is 35 meters square = 377 square feet. In Fort Smith, it averages out to 608 watts over the course of the year; more in summer, less in winter. This also assumes that if it's generating more electricity than it consumes, e.g. during the day, the electricity is captured in a battery to be released at night; OR that the power gets sold back to the electric utility company for the same price as power coming IN from the electric utility company.

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