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Swiss Federal Lab Claims New World Record For Solar Cell Efficiency
Zothecula writes "Scientists based at Empa, the Swiss Federal Laboratories for Materials Science and Technology, have set a new efficiency record for thin-film copper indium gallium (di)selenid (or CIGS) based solar cells on flexible polymer foils, reaching an efficiency of 20.4 percent. This is an increase from a previous record of 18.7 percent set by the team back in 2011."
As opposed to the really efficient gasoline engine. Oh wait - that's only 25% to 30% efficient, and doesn't fuck up the air you breath.
Only 20.4%? That's better than a weather man but worse than an average baseball player. Next!
Not only are gasoline engines inefficient, they require fuel be trucked to stations wasting even more fuel.
Transmission losses like that just make it even worse.
Good luck driving to work in a solar-powered car.
Tesla S, Nissan Leaf, and the Mitsubishi Miev seem to work just fine if you really want a solar powered car.
It seems like every couple of months some solar cell breaks a different barrier. A slashdot story from November (http://tech.slashdot.org/story/12/11/03/2010244/solar-panel-breaks-third-of-a-sun-efficiency-barrier) clocked some solar panel as being 33.5% efficient. Are they measuring on different scales or definitions of efficiency or something?
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Right, because we all know that power plants use gasoline engines to generate electricity? Yeah, no.
Oh and natural gas plants have near 60% efficiency. Coal and oil are in the mid 40s and nuclear in the lower 40s. So yeah, it's still at less than half the efficiency of other generation.
Since it has no cost for fuel, I don't think we can compare it that way and get any real meaning.
If you want to compare area each tech uses to generate a given amount of power, or how much each pollutes per GigaWatt that would be valid.
Right, because we all know that power plants use gasoline engines to generate electricity? Yeah, no.
Oh and natural gas plants have near 60% efficiency. Coal and oil are in the mid 40s and nuclear in the lower 40s. So yeah, it's still at less than half the efficiency of other generation.
The fossil fuels burned in those power plants are nothing but stored solar energy. Given how much solar energy has had to shine on this planet for half a billion years in order to store enough coal or gas to run those generators, the overall efficiency of fossil fuel generation is absolutely abysmal.
This will revolutionise electricity generation in such diverse fields as, uh... space craft and... um... space stations.
If you were blocking sigs, you wouldn't have to read this.
I've been hearing these stories about solar cell efficiency improvements for years and years. Same old lab vaporware.
Until you have product for sale, it's just hype.
"What makes it go?"
Was that physics book that Feynman loved so much written by you?
And typically get most of their power from coal.
You could stick a couple of square meters of solar panels on a typical car, which at 20% efficiency would give you about 240W on a sunny day. For a half-hour commute (fifteen minutes each way) and eight hours in the car park, that would give you about five horsepower if the battery is 100% efficient and you didn't need to use any other electrical items, like AC or headlights.
So it's potentially possible, but would be a really crappy drive.
Coal and oil are in the mid 40s and nuclear in the lower 40s.
What about the power needed to extract/transport all that stuff?
A solar panel has a one-off cost but will produce that 'abysmal' 20% power for many, many years.
No sig today...
Since it has no cost for fuel, I don't think we can compare it that way and get any real meaning.
Yeah, because solar panels and batteries to store power for when there's not enough sun are free.
Trams, trains, underground trains, all run on electricity.
We simply lack the infrastructure to replace cars in any meaningful quantity.
"Oh wait - that's only 25% to 30% efficient"
In a car? More like 10%, and when considered in traffic and city driving, maybe 7 to 8%.
I calculated that my daily commute would requite 3 kWp of panels if the end-to-end efficiency was 75% - which is what Tesla claims for the Model S. 3 kW of panels is 12 panels. That easily fits on my garage roof. This isn't as insane as it sounds.
Yep, 20.4% is crap efficiency, but still better than the electric generator in a Chevy Volt!
That is not fuel, those are capital costs.
All power plants have capital costs. Do you think nuclear reactors just pop into being?
If the input is virtually inexhaustible (sunlight), it doesn't matter how efficient it is. If you have half the efficiency, just double the solar panel area. Total cost per kW and per kWh becomes is more important. Mind you, the panels *don't* need to be on the car.
Ezekiel 23:20
Even if it is 100% coal power, it is still cleaner and more efficient than gasoline.
There is no need to put the solar panels on the car. You can put them on your garage, or buy solar power from the grid.
Which would be great, if you leave your car in the garage all day. Most of us drive around, so if the panels aren't on the car to keep it charged they're utterly useless to us.
I can't decide whether this was a joke or not. For the benefit of those who might not take it that way, I'll point out that these cars have batteries that allow them to collect energy from their garages and (gasp!) drive around with it.
"I zero-index my hamsters" - Willtor (147206)
What about the transmission losses from the Sun to the Earth? /duck
Get free satoshi (Bitcoin) and Dogecoins
Are you mentally handicapped?
You could either store the power in batteries or sell it to the grid and buy back power later when you need it. If you are not suffering some sort of mental deficiency that should have been as obvious as the car not being the ideal place to put the solar cells.
"What makes it go?"
Was that physics book that Feynman loved so much written by you?
Wasn't the answer in the book "energy," which he thought was too nuanced and incomplete, while his "the Sun" example was the kind of thing he said his dad would have taught?
"I zero-index my hamsters" - Willtor (147206)
I feel like I've heard this before:
http://hardware.slashdot.org/story/06/12/06/027228/solar-cell-achieves-40-efficiency
http://tech.slashdot.org/story/12/11/03/2010244/solar-panel-breaks-third-of-a-sun-efficiency-barrier
And of course the energy used to manufacture them is free as well.
Do the math on a solar powered car.....
Assume you could cover the entire top surface(s) of a small car with solar panels and let them charge batteries
all day while the car is parked at work. Assume battery charging is 100% efficient:
Panel Area ~4 m^2 (liberal, but I'm trying to make a point)
Panel Efficiency 20.4%
Time in sun 8 hours
Sun angle derate 50%
Solar input ~1kw/m^2
Then the batteries get charged with 1*4*8*0.5*0.204 ==> ~3.26 KWH
A small car engine is rated at ~200 KW (i.e. Ford Focus Spec at 223 KW)
If you average using only 1/4 the available power ===> 50 KW
The saved energy in the battery will move you for 60min*3.26/50 ===> ~4 minutes
So, you run out of juice about the time you hit the on-ramp of the freeway.
The point being, this isn't going to work unless you have more efficient cells, more efficient vehicles, more
solar panel area, or a combination of all three.
I honestly have no idea what you're trying to say.
Before somebody brings up 40% efficient cells, this efficiency is for a single layer. The 40%+ efficiencies are for so called multiple junction cells which are basically several solar cells stacked on top of one another. This record is for a single layer, for which 20% is really good.
Also, comparisons with petrol engines efficiency are kinda pointless since the advantages and disadvantages of solar is environmental impact and cost respectively. Nobody really cares if it is more or less efficient than petrol. What people are concerned about is environmental impact and cost, which are not easily compared by looking at the efficiency.
That recurring cost and capital costs are not the same thing. Fuel is a recurring cost. Solar panels and batteries are like the reactor at a nuclear power plant which are capital costs.
At about 3" thick, and 3' x 5', I estimate I can get about 20 panels in my minivan. Should be plenty.
No one ever suggested it was, but it is again a capital cost not a reoccurring cost like fuel.
It is bootstrapable though, you could build the first X panels from whatever power then use that to build more.
In reality it does not matter, since the energy used to make the panels is such a small amount compared to what they will produce.
Oh yes it does. If you actually sit down and DO the math, even if you covered the US with solar panels you cannot cover US yearly electrical requirements.
Think about it this way: if you put down 1 billion solar panels that are a meter square each (0.01% of the total surface area of the US), you can *optimistically* supply around 7.5% of the US's electrical supply. (I say *optimistically* because that math assumes best-case incident solar radiation conditions, which the US almost certainly does not get.)
For solar cells, for cancer. Just stop promoting these press releases. When it comes to market as a proven technology, then I'll be impressed.
It's the cost that matters more than efficiency. I don't need a 20% efficient panel that costs 10 times what a 10% efficient panel costs. Really I just want some inexpensive but durable panels. Something where I can recoup my costs in 3 or 4 years not a decade or so.
Dear God, are you strapping them onto the bottom of your van too?
Yeah and I suppose you never park the car in the garage for extended periods of time either. You just park in the fucking pool, right?
http://www.brighthub.com/environment/renewable-energy/articles/65860.aspx 30% or fuck off. Also solar panels are not durable over time and are expensive to make and replace.
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Eventually you need to buy more panels because they don't hold up to, oh, sunlight and air.
Support my political activism on Patreon.
It's all about Storage, Shielding, and Containment. The most egregious flaw in the modern power system is that we have to use it or lose it.
Please stop perpetuating the myth that "most" of our electricity - at least in the US - comes from coal. Coal has been the source for less than 50% of our electrical supply for nearly a decade now and is still declining (Currently around 40%). Even in the worst-case scenario (Colorado, where the local electricity mix is the "dirtiest" in the country) an EV like the Nissan LEAF has the same carbon footprint as a Toyota Prius. It only improves from there.
Also, electricity is fungible. Putting solar panels on your roof to generate electricity during the daytime peak hours even if your car isn't home charging more than offsets the electricity you consume during off-peak hours at night, both in quantity and quality. If anything you are doing more good by putting PV power into the grid than by using it, since you are offsetting peak-generating capacity which is virtually always fossil-fuel based and adding load to soak up off-peak spinning reserve, improving efficiency and reducing energy waste.
=Smidge=
Since it has no cost for fuel, I don't think we can compare it that way and get any real meaning.
It can be done. You simply take the (time) discount value of all cash flows.
Some tech has high upfront costs (solar cells), others have high fuel costs (Coal). All would have maintenance costs. External costs (soot from coal, C02 from fossil fuels) can be handled by a pollution tax. Peak vs. Base could be priced differently. Some wold have a long life - others a short.
Then run it though a Monte Carlo simulation and presto – you have your result - a return on project with confidence internals. Pick the one with the highest return.
If you actually sit down and DO the math, even if you covered the US with solar panels you cannot cover US yearly electrical requirements.
Assuming your numbers are correct, lets say our solar radiation conditions are 10% of the best case. Then to provide all the electricity the U.S. needs, we'd have to cover 1.3333% of the total surface area.
Of course, we can choose the best available locations for each additional panel, so we can do a whole lot better than 10% of the best case. If we can only do half as well on average, the number comes down to .267%. And we can use at least some surfaces for their original use and for solar energy production (rooftop panels).
There are lots of difficulties between here and full solar power. I doubt we'd ever want all our electricity coming from solar power. And even .267% of the surface area of the U.S. is an enormous amount, and acquiring rights to that land would probably be impractical. But if we did need to do it, space wouldn't become the limiting factor for a long time. And if we could solve all of the other logistical problems--storage, distribution, manufacture, maintenance--we would have enough surface area to provide for the U.S.'s energy needs via solar. It just wouldn't be the best way to go about providing electricity.
I saw an interesting comparison made by a professor: If you covered the entire area that was evacuated because of the Fukushima incident with solar cells, they would produce less power than the nuclear reactor did (not to mention how much more it would cost).
PlusFive Slashdot reader for Android. Can post comments.
Eventually you have to buy more power plants too.
25 years is the normal estimated panel life, but I know of panels from the 80s that still work.
Let me know when you can buy a 1KW panel for $50.
If covering 0.01% of the surface area of the US could supply 7.5% of the electricity, covering 100% of the US would supply 75000% of our power needs (under the unrealistic most optimal conditions you state). A billion square meters is only ~33km*33km, which wouldn't even take up a fraction of one of our major southwestern deserts.
There are 311 million residents, why would you only put down 3 square meters per person? The average middle class home roof is approximately 200 square meters and there's a good deal more roof space for businesses. Obviously there are many constraints and other costs preventing that, but it seems like the most optimal conditions would allow for more than 7.5% in roof space alone. You can fit a billion
And still polysilicon reigns as king. Why? It's because this breakthrough still hasn't changed the most important measure which is cost per watt. From a business and consumer perspective that's what matters.
When they figure out how to reduce the cost per watt of solar, let me know. We need a to reduce the cost of solar energy to at least 1/5th of what it costs now if it's to compete with coal. Even if we figure out how to make solar cells out of newspaper .. the cost of battery/storage for overnight will keep it's cost above that of coal. So for solar to be a success we need two breakthroughs .. first and foremost ... how do we make solar cells cheaply? .. And second, .. how do we make cheap batteries?
Think about it, if you are going to build a power plant .. would you spend 5 to 10 times more on it and get unsubsidized solar or will you save money and build coal? That's the question facing power plant builders.
US figures given here... The single most abundant generation source is coal. However, if you combine nuclear, hydro, and renewables, coal is 37.6% vs 30.3% for "non-greenhouse" sources in 2012. If you add nat gas which is cleaner and more efficient even though it does create CO2, total generation from "cleaner" sources is 61.3% vs coal's 37.6%. In other words, it isn't such a bad thing to power your cars with electricity.
source
Methinks you need to redo your math. The reports I've seen say it requires less 1% of the land area. 5 acres of solar panels will produce about 1 megawatt of electricity. Total US generating capacity currently is around 1 terawatt. Assuming solar panels produce about 1/3 of their rated capacity over a 24 hour period that means it would require about 15 million acres of solar panels to cover US electrical production. That sounds like a lot but the area of the lower 48 states is 3,119,884.69 square miles or 1,996,718,413 acres. 15 million acres is only about 0.75% of that area.
And typically get most of their power from coal.
You could stick a couple of square meters of solar panels on a typical car, which at 20% efficiency would give you about 240W on a sunny day. For a half-hour commute (fifteen minutes each way) and eight hours in the car park, that would give you about five horsepower if the battery is 100% efficient and you didn't need to use any other electrical items, like AC or headlights.
So it's potentially possible, but would be a really crappy drive.
Nissan Leaf gets 4.5 miles per kWh. So every hour of charging would get about 1 mile, assuming your math is correct.
my karma will be here long after I'm gone
Was it really record breaking?
http://rsta.royalsocietypublishing.org/content/369/1942/1840/F6.large.jpg
According to this graph they were no where close to breaking the record back in 2011 with 18.7%. I really wish I had a more updated graph but I believe the CIGS were bumped up higher since this graph was produced (back in 8/2010).
You make two claims, since they are in conflict only one can be true. Which is it?
Either 0.01% of the USA area can make 7.5% of our power or coving the whole country would not reach 100% of power generation.
Yes, which is nothing like the comparison the GP was trying to make.
What an astounding troll.
This may work at family gatherings to make that one guy (you know who I'm talking about) who your city niece married look like a fool any time he's stupid enough to bring up the subject of non-fossil fuel energy, but seriously? On a geek website?
Oh wait, what am I kidding. This is Slashdot. I come here for comments like yours that make me realize day after day that I really ought to consider taking Fox News' advice and moving to the socialist utopia that is Europe. I swear I get more liberal the older I get.
Minimal. The loss in a vacuum is inconsequential. The real problem is the way the sun is releasing so much uncaptured energy in all directions.
That's a waste.
Solution: mirrored roads
You should add to the math eolic, tidal and geothermal energy that are as ecologic as solar. Also, probably the most advanced and powerful solar technology is not taken in consideration in your comment: solar satellites collecting solar energy in the space and retrasmitting it to Earth using a decoupled microwave beam. Since solar energy in the space is much more powerful than on Earth where is filtered by the biosphere, it was calculated that a network of solar satellites could provide enough energy for the whole planet, even beaming it on request on spot without the need of any infrastructure.
Have gnu, will travel.
There are two places were putting solar would give the best bang for the buck. As you said, rooftops. If they covered the entire roof, they should make the roof last longer than without the panels. The other place is over roadways. There shouldn't be any problem with right of ways since the roads are already controlled by the government. Also, you would add protection from the elements to those roads which should both prolong the life of the roads as well as reduce the number of accidents caused by adverse weather conditions. Extra bonus points if location transmitters were added to the panel construction to aid in navigation and/or auto-drive cars.
I know someone with a Rav-4 which she charges from solar panels on the roof of her house.
However, unless there's a serious revolution in battery technology, I don't think the electric car is ever going to be practical.
Likewise, solar panels don't work at night, under trees, or when it's cloudy.
None of those are arguments against developing solar technology. Or wind power. While neither of these can ever totally replace fossil fuel power or nuclear, they make excellent supplements. Solar power is at its peak at the same time demand is at its peak. And every kWh of solar power represents 1-2 lbs of CO2 not released into the atmosphere.
This is key. Unless your surface area is limited (space craft, vehicles), it's not efficiency that matters, but cost per watt of capacity.
Make solar cheaper per watt than coal plants (we're getting close now), and then watch all the rooftops in the country get covered with solar panels.
Even if all the rooftops combined aren't enough to produce *all* our needs, every 300MW of solar power is one coal plant shut down, and 2400 tons less CO2 produced. Per day.
Used to do that for a living.
Everything comes down to projected fuel price, availability, load, new generation and hydro conditions.
I can give you all the answers you describe. But like all modelers I can make the model give me the answers I want and you will not be able to catch me without spending weeks on the dataset, then maybe.
Modeling the grid (or any other non-linear chaotic system) more then a few years out is at best a guess, at worst a self serving lie.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
We're not really the geek website you think we are. We used to be, but most of the really smart, and really educated, have moved on. I just wish I knew to where...
It is what? I am not a native English speaker, and I have looked for this word in my dictionaries. I cannot find it. What does it mean? You use it in a manner suggesting that it means "redirectable, can be used in other ways, not limited to what it was created for," but those already have words, so you clearly do not intend those meanings. Just what are you meaning?
And when the electric vehicles become more popular you will probably see some of those huge parking lots being covered with solar cells. And there you have it a parking lot solar farm. :-)
Or, I have already seen panels on a trailer that you can tow behind the vehicle to charge at a remote location.
Something that is fungible means any one instance of it can be swapped with any other instance of it without changing its effects - electricity is electricity, whether it comes from a solar panel on your roof or a nuclear power plant via the grid. http://en.wikipedia.org/wiki/Fungibility
There are two places were putting solar would give the best bang for the buck.
One more: parking lots. Here in San Jose, we have solar panels over several large parking lots. No additional land is needed, and you get the side benefit of shade for the parked cars.
Who are you... Robert Heinlein?
What happened to these guys?
NRL Designs Multi-Junction Solar Cell to Break Efficiency Barrier
by Staff Writers Arlington VA (SPX) Jan 17, 2013
http://www.solardaily.com/reports/NRL_Designs_Multi_Junction_Solar_Cell_to_Break_Efficiency_Barrier_999.html
Schematic diagram of a multi-junction (MJ) solar cell formed from materials lattice-matched to InP and achieving the bandgaps for maximum efficiency.
U.S. Naval Research Laboratory scientists in the Electronics Technology and Science Division, in collaboration with the Imperial College London and MicroLink Devices, Inc., Niles, Ill., have proposed a novel triple-junction solar cell with the potential to break the 50 percent conversion efficiency barrier, which is the current goal in multi-junction photovoltaic development.
"This research has produced a novel, realistically achievable, lattice-matched, multi-junction solar cell design with the potential to break the 50 percent power conversion efficiency mark under concentrated illumination," said Robert Walters, Ph.D., NRL research physicist.
"At present, the world record triple-junction solar cell efficiency is 44 percent under concentration and it is generally accepted that a major technology breakthrough will be required for the efficiency of these cells to increase much further."
In multi-junction (MJ) solar cells, each junction is 'tuned' to different wavelength bands in the solar spectrum to increase efficiency. High bandgap semiconductor material is used to absorb the short wavelength radiation with longer wavelength parts transmitted to subsequent semiconductors.
In theory, an infinite-junction cell could obtain a maximum power conversion percentage of nearly 87 percent. The challenge is to develop a semiconductor material system that can attain a wide range of bandgaps and be grown with high crystalline quality.
By exploring novel semiconductor materials and applying band structure engineering, via strain-balanced quantum wells, the NRL research team has produced a design for a MJ solar cell that can achieve direct band gaps from 0.7 to 1.8 electron volts (eV) with materials that are all lattice-matched to an indium phosphide (InP) substrate.
"Having all lattice-matched materials with this wide range of band gaps is the key to breaking the current world record" adds Walters. "It is well known that materials lattice-matched to InP can achieve band gaps of about 1.4 eV and below, but no ternary alloy semiconductors exist with a higher direct band-gap."
The primary innovation enabling this new path to high efficiency is the identification of InAlAsSb quaternary alloys as a high band gap material layer that can be grown lattice-matched to InP.
Drawing from their experience with Sb-based compounds for detector and laser applications, NRL scientists modeled the band structure of InAlAsSb and showed that this material could potentially achieve a direct band-gap as high as 1.8eV.
With this result, and using a model that includes both radiative and non-radiative recombination, the NRL scientists created a solar cell design that is a potential route to over 50 percent power conversion efficiency under concentrated solar illumination.
Recently awarded a U.S. Department of Energy (DoE), Advanced Research Projects Agency-Energy (ARPA-E) project, NRL scientists, working with MicroLink and Rochester Institute of Technology, Rochester, N.Y., will execute a three year materials and device development program to realize this new solar cell technology.
Through a highly competitive, peer-reviewed proposal process, ARPA-E seeks out transformational, breakthrough technologies that show fundamental technical promise but are too early for private-sector investment.
These projects have the potential to produce game-changing breakthroughs in energy technology, form the foundation for entirely new industries, and to have large commercial impacts.
.
Call me crazy, but until the government/Annunaki/Galactic Federation start charging us for sunlight, why does the conversion rate matter?
Maybe I'm not so good at math, but if the energy input is free, the efficiency approaches infinity. Of course I'm not counting the equipment cost there, because to my way of thinking, a one-time cost for a lifetime of juice is just a sound investment.
I've wished for it, but gasoline still isn't springing up from my backyard magically.
That I'm right, and you don't like it, doesn't mean I'm a troll.
You're not really so dense as to believe the solar panels have to be on the car are you? You're arguing nonsense. That's like saying gas won't work unless you can put all the gas you'll ever need in the car.
Of course it would make more sense to use solar thermal collectors instead of PV in many parts of the US.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
Yes, till then electric car owners typically steal power from buildings anywhere near their work.
You wouldn't cover an area like that with solar PV. Maybe solar thermal collectors, and wind, and in Japan geothermal. Solar PV is most suited to small scale generation, e.g. rooftops.
Picking a dumb scenario that is totally unsuited to solar PV doesn't make this "professor" right, or clever. Nuclear industry shill, perhaps.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
Because items acquired through capital costs NEVER wear out. NEVAH.
It is what? I am not a native English speaker, and I have looked for this word in my dictionaries.
In that case, it means "tastes good with mushrooms". :)
Ezekiel 23:20
The fukushima evacuation zone has a 19km radius. Half of which is sea, so this gives around 500km2 of evacuated area.
The Golmud Solar Park in China with a similar latitude produces 317GWh per year on 5.64km2 and costed around 500 million dollars.
So on 500km2 you would produce 28'000 GWh per year and it would cost 44 billion dollars.
Fukushima produced according to wikipedia 29'891 GWh in the year 2009. Building a 4'800 MW nuclear reactor would cost you around 15 billion dollars. But if you include insurance, waste dispossal, dismanteling and opperating costs, you double or tripple this cost.
So your correct it would produce less energy per year, but only slightly. And the overall cost would probably be higher but also only slightly.
And typically get most of their power from coal.
Here in Portugal, half of my electricity comes from renewable sources. 35% of it comes from wind power. 20% comes from coal. But maybe a rich and big country can't do the same things a poor and tiny country does.
I can't decide whether this was a joke either.
For the benefit of those who might not take it that way, I'll point out that if you actually use your car in the daytime, it's not going to be in the garage charging while the sun is up, it's going to be...elsewhere....
"I do not agree with what you say, but I will defend to the death your right to say it"
Yes, it is these stupid "You have to show me the Earth is flat before I can accept the Earth is round" arguments that hold back progress.
For the benefit of those who might not take it that way, I'll point out that if you actually use your car in the daytime, it's not going to be in the garage charging while the sun is up, it's going to be...elsewhere....
I don't think it was a joke, way too deadpan.
BUT, he would be correct if he were talking about a grid-tie system. Those essentially treat the grid as a battery - send surplus electricity into the grid during sunlight hours and then draw power from the grid at any point during the day.
Some states are really grid-tie friendly because they have time-of-use billing which means they pay you more for electricity generated during the mid-day than they charge for electricty consumed at night. Some even given you a further break on the price if you have an electric car - they will give you an extra discount on enough units to charge the car each night.
When information is power, privacy is freedom.
with all due respect to the good professor, that's a pretty stupid comparison to make.
> (not to mention how much more it would cost)
you mean with or without the radiation disaster and evacuation?
~.~
I'm a peripheral visionary.
Ok, let's do the math. Total electrical consumption (not all energy usage, just electrical) for the US is about 480 gigawatts. Average insolation is about 1 kw per square meter. At 10% efficiency, that means about 100 watts for every square meter of panel. That means you need 4.8 billion square meters of panels. 4.8 billion square meters can fit into a square 69.282 kilometers on a side. That's somewhere between the size of Rhode Island and Delaware.
Even if you expand that to all energy usage, not just electrical, you're talking approximately 3 terrawatts. So, that's about 30 billion square meters of panels. That's a square about 173.2 kilometers on a side. That's somewhere between the size of Maryland and Hawaii.
So, if you actually sit down and DO the math, you can easily cover US electrical requirements and, in fact the total US energy usage (not counting food energy and not considering the fact that much of that energy usage can't currently be converted to electrical) without coming remotely close to covering the US with solar panels.
Of course, if you'd actually done the math on your own claims, you would have realized that, when you claimed that you could "optimistically" supply 7.5% of the US's electrical supply with 0.01% of the surface area, that would mean that you could "optimistically" supply 100% of the electrical supply with 0.133334% of the surface area, or even pessimistically (let's pretend that the difference between "optimistic" and pessimistic is an order of magnitude) with 1.33334% of the surface area.
So, it's pretty clear that you either didn't do the math yourself, or you just decide to bluff. If you meant something else, like that there are logistical problems in covering that much area, then say so.
What were the numbers on that? The number I can find for the evacuation area is a 19 km radius, which is 1134 square kilometers. Covered in solar cells, assuming about 100 watts per square meter (10% efficiency with 1 kw/square meter insolation), that should produce 113.4 gigawatts. From what I can find, Fukushima Daiichi had a maximum capacity of 7.456 gigawatts with a typical production of 4.696 gigawatts. The power plant site itself was 3,480,299 square meters. So, just the power plant grounds covered in solar cells could have produced 348 megawatts, which would be about 7.4% of its capacity.
Beyond those numbers, I wonder what the real footprint of the plant was. We should ignore initial construction, but we can't ignore that the power plant ran on fuel that required mining and processing. Perhaps all processing was done on site, but the mining and basic refining couldn't have been. How much area was devoted to acquiring the nuclear fuel for the plant? Uranium mining tends to eat some pretty hefty chunks of land. I did a search for info on how much land it actually takes up, but can't find a source that has already compiled a number. It does seem possible that it could use up even more land than the power plants themselves. If it manages to make it to 14:1 for Fukushima Daiichi, that would mean that the land area devoted to generating the nuclear power could be covered in solar cells instead to produce the same power. It's obviously a bit more complicated than that, but it's still very interesting.
it's not efficiency that matters, but cost per watt of capacity. Make solar cheaper per watt than coal plants (we're getting close now), and then watch all the rooftops in the country get covered with solar panels.
+5 insightful. So many of the haters miss that point - We don't all live in Urban Hell. I don't care about finding a way to squeeze 99% of the energy out of the 10 square feet of sunlight falling on the south side of my apartment between the skyscrapers; I care about about the cost per Watt.
And never mind just rooftops - Find a way to sell me nearly-disposable panels for a few bucks per square meter, and I'll pave a quarter acre of my yard with the damned things, and sell all the extra clean power to those trapped in Urbia (hmm, why do we say "suburbia" but not "urbia"?).
As it stands, we can already get panels that will break even vs their purchase price within a few years. Make that a couple of months, without a 20-30k upfront cost, and watch our present energy crunch vanish overnight.
He wasn't suggesting that. Maintenence cost != fuel cost.
The life expectancy of a solar panel tends to be better than the life expectancy of a car. Cars and their engines also tend to be expensive to make and replace. A new engine for my sisters car would cost $3,745.00 and is 113 kg. And can produce something like 180 kilowatts optimistically. Of course, it would burn out fast actually producing at that rate. The operational life, actually running, tends to optimistically be about 7 months for a car engine in a car. So, a kilogram of car engine could be said to produce 1.6 kilowatts per kilogram at a cost of $20.80 and lasts 7 months and would consume about A kilogram of thin film solar cell (not counting the glass panels), have demonstrated power levels above 1 kilowatt per kilogram and would almost certainly last for 20 years, which would mean at least 21.4 times the power production of the car. Of course, at the moment, I can't say for sure that the solar panels would cost less than the $445.00 to make it even in lifetime power production with the car engine. Of course, the solar cells wouldn't need the approximately 270 gallons of gasoline the kilogram of engine would use in that time, adding another $810.00 (at an optimistic $3.00 per gallon) to the cost of the car engine power.
Overall it's clear that it's really hard to directly compare these things. Achieving the power density of a car engine with solar cells placed on a car is clearly impossible on this planet. Achieving the abundance of solar power with any fossil fuel is also a clear impossibility since fossil fuels are just solar power stored with miserable efficiency. Personally, I have high hopes at the moment for air-breathing batteries with similar energy density to fuels like gasoline (at least 50% of the density would be all that would be needed), but they also need to have sufficient recharge cycles and low enough cost so that periodic battery replacement plus cost of recharge power doesn't exceed the cost of gasoline. The recharge cycles problem is a technical problem that probably can be solved. Ditto for the cost of recharge power. The cost of replacement batteries, however, is at the mercy of car manufacturers, salivating at the prospect of collecting monopoly rents from captive customers. Pity.
The point of this one is that it's a new record for the (potentially) cheap, continuous, roll-to-roll manufacturing process.
A lot of stationary sites are more sensitive to $/installed-watt and $/(installed-watt * ammortized-lifetime). If a process is half as efficient as other alternatives but an eighth as expensive, and there's plenty of surface area to pave (like on a house roof).
What would make it BIG news is if the win is enough to jump it substantially beyond breakeven vs. grid power.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
FWIW, it's becoming fashionable in Silicon Valley to use solar panels as shade structures in parking lots. The cars get much-needed shelter, and solar panels get installed without covering up anything like lawns or gardens. It's a complete win-win.
If the input is virtually inexhaustible (sunlight), it doesn't matter how efficient it is. If you have half the efficiency, just double the solar panel area. Total cost per kW and per kWh becomes is more important. Mind you, the panels *don't* need to be on the car.
Efficiency does matter if area is a concern. A home may have enough roof space for solar PVs to charge a storage system or th power the home but may not have enough for both. Increasing efficiency may allow both to be done.
And that is if there is a battery bank big enough to allow an EV, Electric Vehicle, to have it's own battery system be charged over night. Of course with net metering the grid serves as storage during the day so the EV's batteries are charged at night from the grid.
Falcon
Should there be a Law?
Make solar cheaper per watt than coal plants (we're getting close now), and then watch all the rooftops in the country get covered with solar panels.
I bet if solar, and geothermal and wind, was subsidized as much as coal and nuclear power was they'd be cheaper. And yes, both coal and nuclear power is subsidized. Here's Rep Edward Markey in 2009 practically bragging that nuclear power got $145 Billion while solar and wind got $5 Billion in subsidies. He goes on the say his bill has "Huge Subsidies for Clean Coal".
If all subsidies for clean alternative energy was added together it would not be close to how much coal and nuclear power gets. If coal had to pay for pollution and nuclear power had to get it's money from a free market I doubt either one would be in business today.
Falcon
Should there be a Law?
Which is why the best place for nuclear power stations and for solar cells are in Arizona (or Sahara). A blow-up of a nuke or installation of a massive solar power system will only affect the nasty poisonous desert critters.
Japanese are screwed either way because of their massive population density and earthquake prone-ness .Wind Towers need be stronger, dams shorter, nuke reactors safer in Japan and solar near impossible
And typically get most of their power from coal.
That depends on where you live. PNW is mostly hydro. France is mostly nuclear.
I think this is almost like the flying car scenario. A true Solar car would generate its own power and store the excess for night driving (when it's parked for example). And let's not assume for now that Solar = electrical.
The fact that this is impossible to do today, doesn't make the concept stupid. We don't have solar cars as yet - they are electric cars and they don't need solar energy to operate.
Don't be apathetic. Procrastinate!
The article does not mention sample area (in, say, mm^2). Does anyone know what it is?
A pollution tax doesn't work because it doesn't actually do anything about all of the greenhouse gasses and soot which damage the environment. You'd have to factor in the cost of a CO2 scrubber and permanent storage of all produced CO2, and carbon offsets of both projects in trees planted.
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And with solar power, until an efficient energy storage method is created (batteries and other methods available now are crappy), transmission problem is going to last and even grow bigger. In my opinion, the only sensible solution to powering all the world from solar would be to build power plants on opposite sites of the globe, so some part of them is ALWAYS on the dayside. Transmitting their energy to those parts of world that are currently on the nightside is even bigger a problem.
not 4.696 gigawatts!
4.696 Megawatt! ~ 5 Gigawatt
off by a factor of 1000
powerplant ~ 5 Gigawatt
evac zone@100w/m2 ~ 100 Gigawatt
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Did they calculat how many kg of solar panels you can install on earth for the energy it takes to put one kg of solar panel in orbit?
You can add those losses into the gasoline cycle too. Also while we are there, add up all loses from sunlight to gasoline.
We can fix that by building a massive parabolic reflector around the sun.
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maybe a rich and big country can't do the same things a poor and tiny country does
There's a lot of truth in this. For example, Brazil invested heavily in biodiesel because it could not afford to import oil. If you have a lot of spare money, then it's much easier to just put up with the increasing prices of fossil fuels. The same thing happens on a smaller scale with companies, where a startup has to innovate to be able to compete with larger, established companies, because it has to have some edge to offset the economies of scale that the big competitor has. Similarly, the larger company can rely on its economies of scale to offset inefficiencies in their workflow.
I am TheRaven on Soylent News
Similarly, the larger company can rely on its economies of scale to offset inefficiencies in their workflow.
Yes, and we all know how it ends, don't we?
There are technical and social problems - and solutions. The direction of power technology has changed, now goes toward cleaner power. Whatever current technologies allow, in time there will be ways to generate clean power competitively. Germany is most likely to get there first. Public and government have reached consensus to get it done, are working on it nonstop, and are way ahead of everyone else, facing problems and solving them. If the US decides to keep depending on old technologies, for whatever reasons, it might have to pay a price for it. Such as being stuck with a massive industrial and technical infrastructure of oil-based equipment and technologies, when it becomes economically, technically and politically obsolete, and a huge burden.
You solve that with diversification...
solar, wind, tides, hydraulic , geotermal, biofuel/biomass, etc
If really needed, some nuclear, but only as last in line.
Instead of having huge electricity production center, we should use local production from multiples sources, each one could plug the holes in production of the other.
There is no "one size fits all" and trying to do that will always create new problems
Higuita
For comparison, photosynthesis (which powers all life on Earth) is less than 1% efficient.
Myth? Look at china Europe and south pacific. About the only place moving away from coal is the US. That is because NG is way cheaper right now (that will not last). Pretty much everyone else is running to coal away from nuke.
Serious question for you – what do you think the right answer is? In my mind there are 2 choices.
You can try to model the future – recognize the limitations – and go from there. That is a poor map is better than no map at all. I think this is the right choice. Yes, after a few years the inputs break down – but at least you know what sensitivities your system has.
Or you can buy into Nassim Nicholas Taleb’s black swan theory – that a poor map leads to overconfidence and thus failure – and thus it is better off not to have a map.
Let me put forward a real life example – just to make sure I am not missing something.
Carbon capture (best guess) runs around $40 a ton. Insulating my roof costs $20 per carbon ton (in energy not otherwise produced at my local coal fired electrical plant).
Won’t a $30 pollution tax result in my putting more insulation in my roof – a rational allocation of resources which would result in the biggest change for the least dollar amount?
I have seen a lot of interesting maneuverers around alternative energy (wind, ethanol, natural gas vehicles) which are profitable from a tax perspective but not from an economic or green perspective. In my opinion, the more complex the regulations are to prevent abuses the more loopholes there are for abuses.
A flat $40 tax per ton of carbon on all industries (with some carbon offsets) would be a simple, fair method resistance to abuse.
---
Solar Power Feed @ Feed Distiller
You are going for the wrong comparison, the correct comparison is:
Solar, up to 20% efficient at converting free energy (light).
Gasoline..it's not free, it's getting more and more expensive to get it out of the ground and the higher quality stuff is starting to run out right now.
And I don't know why we keep getting articles about efficiency when it is obviously cost, ROI time and subsidies that really matter.
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Totally agree that we need diversification. The whole reason why we have such an issue with CO2 emissions from out electricity is because at one time, we used 75% of our energy from fossil fuel. We are now below 50% total, and converting coal to NG along with some AE, but it is really not enough.
In fact, I think that ppl are INSANE to push just Wind and Solar. Imagine if yellowstone goes. That will cut out a large amount of sun for America and in fact, the entire northern hemisphere. Without as much sun on the lands, your winds DROP fast. IOW, you lose solar AND wind. So, when you need the energy the MOST is when you will be gutted. It also makes it easier to attack a nation that way, by putting up clouds. You will note that the Chinese PLA is working very heavily on weather control.
Indeed, we need Wind and Solar, but limit it to no more than 25% or so, but allow for output up to say 33%.
Hydro is currently at 7% and can be raised to a total of 13%.
Likewise, add in geo-thermal (base-load power regardless of weather) for a max of 33%, but with a capacity of say 40% (this way it lasts longer). We need nukes esp, thorium for say 33%, but allow it to float upwards of say 40%.
Finally, we NEED to have smaller grids with storage. By creating smaller grids, it helps isolate blackouts and other issues. With the storage for these grids, it allows time for switch-over and issues. Even a 10 minute storage at peak is more than enough.
With the above, we can get off fossil fuel, though we will need fossil fuel for the interim. Though even here, the smart move is to Natural gas, rather than oil.
Windbourne.
not 4.696 gigawatts!
4.696 Megawatt! ~ 5 Gigawatt
off by a factor of 1000
I'm assuming you were educated somewhere where the comma (,) and the period (.) have opposite usage in mathematical notation to the way I use them. It's an unfortunate problem with mathematical conventions. To be clear, when I wrote "4.696 gigawatts" I did not mean: "four thousand six hundred and ninety six gigawatts", but rather "four gigawatts plus six tenths of a gigawatt plus 9 hundredths of a gigawatt plus 6 thousands of a gigawatt". If I had intended to express any number of thousands of gigawatts, I would typically have jumped up to terawatts. If I'd only thought to round up to avoid three significant digits after the decimal point or if I'd written "1,134 square kilometers" instead of just "1134 square kilometers", this could have been avoided as it would have been more obvious from context that I wasn't using the period as a thousands delimiter. On the other hand, other context, such as the way I wrote "113.4 gigawatts" or the way I spelled "kilometer" or just the fact that I'm writing in English on a US-centric website was available.
powerplant ~ 5 Gigawatt
evac zone@100w/m2 ~ 100 Gigawatt
That is correct, and is what I was trying to say. The professor quoted by the original poster was obviously wrong since the evacuation area covered in solar cells would produce approximately 20 times the power of the plant itself (actually only about 10 because I forgot that about half of it is water).
I'm wondering if misunderstanding of my units was why I was actually modded down as "overrated" when the original hearsay post which didn't list any of the facts or math used to reach its conclusions, was modded to +5 informative. But that seems unlikely on Slashdot. Most readers here wouldn't have misread the units the way you did.
In any case, the other point from the original post I didn't address was cost. pi*19000^2 is 1134113990. That's the number of square meters in the evacuation zone, but we'll halve it because of the water to 567056995 square meters. We can just call it 570 million square meters. Covering that with solar cells would surely be expensive. The problem is, the unnamed professor in the original post has set an interesting challenge by saying that covering the evacuation area with solar cells would both produce less power and cost more than the nuclear plant. The problem is that, since the first claim is false by an order of magnitude, do we have to disprove the second claim only for a tenth of the area, or do we have to hand victory to our invisible opponent on half of his claim even though the second claim clearly should only be considered in conjunction with the first?
I'll have to start by saying that I couldn't find numbers for the construction of operating costs for the plant, although there was lots of information about the cleanup costs. New nuclear construction seems to about $5000 per kilowatt though, so we can maybe estimate $25 billion ($25X10^9). Hard to say if that's accurate or not, but it looks like it's certainly going to end up costing more than that in the end. So, if we divide $25 billion by the 570 million square meters for the solar cells, we get about $43 per square meter. It is hard to beat that with solar cells. The best price I could find in a five minute search was $49 and 32 cents per square meter just for the cells and obviously there would be more infrastructure required. Of course, since that's for 10X the production of the nuclear plant, it seem more fair to compare say that you have $430 to spend per square meter, which is much, much more reasonable.
Actually, in America, about 36% of our electricity comes from coal (and that was 2 years ago). With the plants being shut down due to W/neo-con's mercury laws, coal will hit below 25% around 2016.
So, claiming that most comes from coal, is pretty silly.
And none of the cars have enough solar panels on them to power them. It is just as silly for ppl to make that claim as it is for you to claim that most of the electricity comes from coal.
Windbourne.
That used to be true only due to the high costs of Solar PV. At this time, Solar PV is cheap enough and becoming cheaper all the time. As such, Solar thermal will never compete except in specialized cases. In addition, solar thermal is really only useful in the south west, or less than 1/4 of the USA. And that is being generous.
Windbourne.
I agree that something like that would help in preventing people from externalising costs (instead of reducing costs). The trouble with that is that there will inevitably be corruption and loss based on where that tax money goes to. If it is put into installing atmospheric CO2 scrubbers, then sure, but somehow I don't see that happening. Also, just because there is a market option for something which is cheaper doesn't always mean it will be taken, otherwise everybody would have heat-pumps instead of furnaces and would drive plug-in hybrids instead of automatic transmission V8 SUV 4x4s.
Help I am stuck in a signature factory!
You try to model the future but don't let it get into the hands of morons who don't know the difference between 'could happen' and 'will happen'. These models are engineers tools and are very dangerous things in the hands of MBAs. We made GUI tools (we had to) but this is one place where hiding complexity leads to black swan. If you go to a model, understand it or really, really trust the person doing the modeling for you. '
'My' product (I wrote it, but touched the whole suite excepting the FORTRAN) was a short term shell. It hid complexity, but still required someone to understand the model, just not the trader/operations guy on the desk. The trader/operations dude posted his question sort of spreadsheet style (e.g. can I afford to shutdown X or should I run it de-rated and fix it later). The software grabbed initial conditions from SCADA (or whatever, it was separate process, why I've hit every GD database known to man) and fires off the model in all it's ugly complexity, loads the results into the database and runs reports (usually deltas in operations cost). The operations guys are all old shrewd operators who understand limits to tools. They face tough problems. e.g. in S. Florida you have to forecast your gas burn x days ahead (where x is the gas transit time from the terminal to your plant), x is greater then your reliable weather forecast.
You recognize that models don't prove anything. Once you've got to the level of dataset manipulation that you can generate the results you want, you are now qualified to critique the datasets of others. Modeling in front of energy boards is an adversarial process, like court. Too bad most board members are political appointees who have their minds made up and can't follow the discussion anyhow.
You also learn to appreciate that all the serious market players are running the same simulations (we sold them the tools) and coming to different conclusions. You don't have to find the 'optimum answer', that's for the navel gazers in operations research. You find an answer good enough to keep you in business (or not).
As to using a model to decide weather to build a metric shitload of PV? Waste of time IMHO. Variables are unmodelable. Government subsidies and their duration? Future price of peak power (what your utility pays, just backfit a growth rate, it will be as close as anything). Future cost of peak power (the price you pay, again backfit a growth rate). I can't see any sense in installing more then your own peak use. Difference between your return being cost or price.
There is only one good reason to install as much PV as you can fit on your roof. It makes hippie girls puddle. Which is why I installed fakes. Much cheaper.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
The problem is, that only nuclear and solar have enough power output in most of places on this planet.
The other problem is that we need either good energy storage for our cars or the possibility to quickly charge them every 50 or 100 kilometers...
I was more indicating that there is a more efficient design (30%) that uses a parabolic reflector to focus sunlight onto a sterling engine, which if it works will continue to work forever. Possibly requires maintenance; the working temperature is 1200 degrees, which means you can't run an Alpha sterling with Teflon seals and bearings since it needs to be kept under 500F. Note that you no longer need to grease your car's chassis because the bearings are all Teflon.and still work 150000 miles in.
Even with maintenance--a little synthetic grease now and then, occasionally replace some seals and rings--this design takes less energy to produce and costs less to upkeep. The sterling engine is effectively a big metal block; the parabolic reflector should be cleaned and polished if it gets dirty or starts to weather. In the end we can recycle them. They are produced with heat, not with harsh chemicals. Melting metal is easier than melting glass (good quality glass softens around 4000C; cheap lime glass will do it at 1200C; Steel is worked below 1100C). Engines are macro-scale mechanical machines where physical shape is to higher tolerance in some (few) places than others; solar panels rely on guiding subatomic particles such as photons and electrons in a fairly precise manner and will not function well (or at all) if there are compositional defects anywhere throughout the substrate, either at manufacture or forming later--this includes oxidization and chemical breakdown from exposure to light and heat, which in a machine is why you change the oil (rather than replace a whole panel).
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How do you compare a sterling engine to a car engine? A car engine has to deal with explosions happening inside it. It has to deal with sharp reciprocation at high force. A sterling engine has constant energy pumped into and out of it and rides a smooth power curve. Sterling engines do not compress, start to peak, then have high amounts of energy from burning energy-dense fuel slammed down their throats to shove the piston back down.
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How do you compare a sterling engine to a car engine?
Only on a limited set of parameters and in the context of a larger system. For example, if you had two otherwise identical cars, one with a "sterling[sic]" engine powered by a small gasoline furnace and one with an internal combustion engine, you could compare the two cars on details such as miles per gallon, max RPMs, engine torque, engine responsiveness, etc. Generally speaking, the comparison between gasoline engines and Stirling engines in the context of cars just doesn't work because Stirling engines aren't really suitable for that application for a number of reasons, such as responsiveness. You clearly already know this. Stirling engines would be much more suitable for systems that buffer the power from the Stirling engine somehow, such as in hybrid cars with all-electric drive systems but with a combustion engine purely for generating electricity. In a system like that, you could make a more direct comparison between the internal combustion engine and a Stirling engine doing the same job.
Of course, I'm not sure why you brought up Stirling engines. I certainly didn't mention them in my post. In my post, I was responding to your post:
30% or fuck off. Also solar panels are not durable over time and are expensive to make and replace.
Where _you_ were also comparing apples and oranges. The "efficiency" of an internal combustion engine is clearly not the same thing as the "efficiency" of a solar cell. To directly compare them, an "efficiency" number would have to be adjusted based on all kinds of facts about the broader system they're a part of, otherwise it's meaningless.
You felt the need to talk about the durability of solar cells in a discussion about solar power vs. combustion engines in the context of powering cars, so I responded. Solar cells cost money to produce and have limited lifetimes. Car engines cost money to produce and fuel and have limited lifetimes. Over an optimistically long life, a car engine optimistically uses up about 39X its initial cost in fuel. Basically, the car engine can't hold a torch to the solar cells in terms of lifetime cost for the power it outputs (ignoring that one is outputting mechanical power and the other electrical). On the other hand, unless we move a lot closer to the sun, solar panels can never compete on power density to internal combustion engines in a car application because of the limited surface area. Still, internal combustion engines can't really compete with electric motors in nearly every way that makes them useful in a car which would make stationary power generation (possibly though solar cells) and electric cars a wonderful idea if it weren't for the electrical storage problem.
Did you see the link posted there? They get 30% efficiency from their solar collector by putting a big metal mirror satellite dish on the ground and pointing it at the sun, with a sterling engine at the focal point. The hot side heats up to 1200 degrees, the engine pumps, the output drives a dynamo. Since when is a combustion engine. God damn man the link is the first thing in the post and there's no mention of cars or engines in the actual post.
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You are still thinking in a big and central power generation system. you need weaker ones, but close to those how need it.
As for "enough power", hydraulic have enough power in many countries (who have big rivers), but those without rivers and mountains might be hard... ... but wind have enough power output is most places... Portugal and Spain already went above 50% wind generation of all power produced, using big and improved wind mills (check this and this ). Most places in the world have windy spots that can be "farmed"
If you have dams "near" you can use the excess wind to pump upstream water, that will be used later when there is a need for more power of the wind is weaker.
yes, its possible that there is no win, but its also possible that the clouds break the solar power output. Nuclear and biofuel/biomass can be used on that time
finally, the current batteries arent the future. Unless there is a big change, biofuel and Hydrogen/ ("manufactured") Metane will be the future for cars. Batteries right now are very expensive, heavy and die too fast. they are good enough for a hybrid car, but not so much for a 100% electric car
Higuita
Wow. I'm so totally in the wrong on that one. I even still have the tab open in firefox for that article, unread. I misread things and thought the 30% you posted was a reference to the efficiency of gasoline engines against solar panels. I apologize for that. Clearly I deserve to be slapped around with a cluestick for a while.
Anyway, you're absolutely right, there are far more efficient ways to build solar power plants than photovoltaic. They're useful to produce extra power on rooftops, and parking areas, etc. where you can't necessarily build something like in the article. They're also useful in discussion as a baseline solar technology. If you can demonstrate that solar cells would beat some other technology in performance/cost/etc. then something like the parabolic concentrator system you linked to would do an even better job.