Beta

Slashdot: News for Nerds

×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Stanford's New Solar Tech Harnesses Heat, Light

Soulskill posted more than 3 years ago | from the doubling-down dept.

Power 117

An anonymous reader writes with this excerpt from a Stanford news release: "Stanford engineers have figured out how to simultaneously use the light and heat of the sun to generate electricity in a way that could make solar power production more than twice as efficient as existing methods and potentially cheap enough to compete with oil. Unlike photovoltaic technology currently used in solar panels — which becomes less efficient as the temperature rises — the new process excels at higher temperatures. ... 'This is really a conceptual breakthrough, a new energy conversion process, not just a new material or a slightly different tweak,' said Nick Melosh, an assistant professor of materials science and engineering, who led the research group. 'It is actually something fundamentally different about how you can harvest energy.' And the materials needed to build a device to make the process work are cheap and easily available, meaning the power that comes from it will be affordable." The abstract for the researchers' paper is available at Nature.

cancel ×

117 comments

blah (-1, Redundant)

Anonymous Coward | more than 3 years ago | (#33114102)

FIRST

!First (-1, Offtopic)

Binkleyz (175773) | more than 3 years ago | (#33114126)

Cheap AND easy?? You can count me in!

*Yawn* (3, Insightful)

sycodon (149926) | more than 3 years ago | (#33114654)

Call me when I can pick it up at Home Depot.

Solar energy. It's NOT just a technical problem. (3, Insightful)

gestalt_n_pepper (991155) | more than 3 years ago | (#33115182)

Ditto. I'm getting truly sick of these "improvements in solar technology" stories that turn out to be little more than research lab oddities, penny stock scams, or something so expensive that it will never be commercially viable.

When it looks like Joe-Bob can buy a system for under a thousand at Wal-Mart, and the system is so idiot proof, that even Joe-Bob can plug it in and make it work without killing himself or burning down the trailer, you have something.

Until then, even if it works, solar is still just a rich man's toy.

Solar energy. It's NOT just a technical problem. It's an economic problem.

Oh, it's still a technical problem too. (3, Interesting)

Orange Crush (934731) | more than 3 years ago | (#33115940)

Even if the tech gets to a point where Joe-Bob can buy a 5,000 watt solar array at Wal-Mart for $999, he won't be able to install it permanently in a safe manner, because you're still dealing with 5,000 watts. It becomes nothing more than a fuel-less generator. Mounting it permanently on his roof, tying it in to his household wiring and setting up a grid-tie net-metering arrangement will still take the work of professionals.

Of course, we may someday get to a point where the process is simplified and routine enough that installation costs might approach something like putting in a tankless water heater, gas lines or satellite dish.

Re:Oh, it's still a technical problem too. (1)

lordlod (458156) | more than 3 years ago | (#33118236)

Wiring in a solar array to your household wiring is the work of professionals the same way wiring in a kettle is. Once it's common we will solve it the same way, you create a standard plug in a suitable location and just plug it in. The same thing is happening with roof lighting circuits. You used to have to get an electrician to wire each light in, now he puts a standard appliance socket near the hole in the roof and the light plugs in like any other appliance, now anyone can fit or change it.

5000 watts in a complete non-issue. In my country standard household circuits are 20 amps or 4800 watts. Often a 20 amp three phase circuit can be found in a house, that's 7200 watts. All these come with standard plugs that anyone can connect without qualifications.

Re:Oh, it's still a technical problem too. (1)

ScrewMaster (602015) | more than 3 years ago | (#33119346)

Wiring in a solar array to your household wiring is the work of professionals the same way wiring in a kettle is.

It's not THAT difficult. You need a synchronized inverter.

Re:Oh, it's still a technical problem too. (0)

Anonymous Coward | more than 3 years ago | (#33118492)

I think what the OP was getting at was that it needs to be idiot proof, ie place outside plug into wall, walk away to never think about again. Yes this is a technical problem, but the current thinking right now in the solar industry seems to be about large industrial usage. It seems to me to be an easier problem to solve if they focus on making it somewhat like a water heater, it's part of your house you really don't think about it unless it breaks. When it does you call a tech to come out and fix it, the end.

Cost per watt chart? (2, Insightful)

MyLongNickName (822545) | more than 3 years ago | (#33114164)

Can anyone point me to a good cost/watt chart over time? I would love to be able to see how prices have dropped over the past two decades. I keep hearing that solar has to drop in price... but have no baseline to judge our progress.

Just the GaN achieve in 40% range (3, Interesting)

dch24 (904899) | more than 3 years ago | (#33114232)

What I want to know is what mechanisms are causing their Gallium-Nitride junction to conduct more reverse current above 227 C.

They are currently projecting operating at 200 C for max efficiency but if it's as I suspect -- increased current flow with higher temperature -- then they can modify the doping mixture to get even higher temps and therefore higher efficiencies.

This would also boost the Carnot Cycle efficiency limit for the secondary heat exchanger that operates after the GaN primary power generation.

I'm reading from the slides [nature.com] .

Re:Just the GaN achieve in 40% range (1)

pspahn (1175617) | more than 3 years ago | (#33116088)

uh, this?

Re:Just the GaN achieve in 40% range (1)

tyrione (134248) | more than 3 years ago | (#33116100)

What I want to know is what mechanisms are causing their Gallium-Nitride junction to conduct more reverse current above 227 C. They are currently projecting operating at 200 C for max efficiency but if it's as I suspect -- increased current flow with higher temperature -- then they can modify the doping mixture to get even higher temps and therefore higher efficiencies. This would also boost the Carnot Cycle efficiency limit for the secondary heat exchanger that operates after the GaN primary power generation. I'm reading from the slides [nature.com] .

You'll know after they receive the much deserved Patents, if this is proven correct.

Re:Cost per watt chart? (2, Informative)

Anonymous Coward | more than 3 years ago | (#33114240)

What a coincidence, I just happen to have a chart for the last ten to fifteen years here:

http://thephoenixsun.com/archives/10688

Re:Cost per watt chart? (0)

Anonymous Coward | more than 3 years ago | (#33115294)

Oh, you mean the chart which recently accompanied a completely bogus, misleading article, which misrepresented both solar and nuclear costs, and then provided a graph of the completely bogus and misleading data.

Nice!

Re:Cost per watt chart? (4, Informative)

TooMuchToDo (882796) | more than 3 years ago | (#33114298)

Re:Cost per watt chart? (1)

skids (119237) | more than 3 years ago | (#33114464)

The caveat on that chart is it tracks Silicon based technology only, so you only see the impact of thin films via market price pressures, not directly. FWIW.

Re:Cost per watt chart? (1)

Marcika (1003625) | more than 3 years ago | (#33115094)

The caveat on that chart is it tracks Silicon based technology only, so you only see the impact of thin films via market price pressures, not directly. FWIW.

No, it seems to track them regardless of manufacturing method, but the graph tracks some sort of average price index across all manufacturers. They mention in the news release that: "as of July 2010, there are now 518 solar module prices below $4.00 per watt (€3.20 per watt) or 36.4% of the total survey. [...] The lowest thin film module price is at $1.07 per watt (€0.86 per watt) from a United States-based retailer."

Another caveat: These are single-module, retail prices -- obviously it gets cheaper if you buy a couple of MWpeak worth of modules for your powerplant...

Re:Cost per watt chart? (1)

skids (119237) | more than 3 years ago | (#33116528)

The graph tracks Si module prices. It used to say that explicitly. That may or may not still be the case explicitly, but there just aren't that many thin film modules above 125W, which is what they do say now. IIRC they used to restrict it to mono-Si. Even if they are allowing multi-Si now, modules above 125 are less common in that product space because they have to be pretty big to pull in that much power, so mono-Si will be overweight in that chart, at the very least.

The thin film prices mentioned in the text, would not influence the chart itself.

Re:Cost per watt chart? (1)

Marcika (1003625) | more than 3 years ago | (#33116996)

OK, I stand corrected...

Re:Cost per watt chart? (1)

bill_mcgonigle (4333) | more than 3 years ago | (#33116688)

I was going to dismiss this as "not much movement" but then I remembered about inflation. $4.10 in 2010 would be about $3.30 in 2001, so 5.40/3.30 = about a 64% price improvement. That's fairly respectable, though it still looks like decades until it's 'cheap'.

Re:Cost per watt chart? (4, Informative)

dch24 (904899) | more than 3 years ago | (#33114300)

Can anyone point me to a good cost/watt chart over time? I would love to be able to see how prices have dropped over the past two decades. I keep hearing that solar has to drop in price... but have no baseline to judge our progress.

It depends on what you want: space solar panels are the most expensive multi-junction technology, but achieve the highest efficiency.

If you're a huge company, you can get really great deals because you purchase whole manufacturing runs. This is also why it's hard for an individual to buy direct from any manufacturer: all their production capacity is probably already bought up by large companies, so you get the "seconds," the panels that those resellers decide they would like to sell to you (at a price mark up, of course).

Here are some panel price charts, though they're not perfect:

http://www.solarbuzz.com/Moduleprices.htm [solarbuzz.com]
http://futurist.typepad.com/my_weblog/2007/08/solar-energy-co.html [typepad.com]

But I should point out the bias on these sites: they're in the industry, not independent review sites. So they will be competing to drive your dollars to their products.

Re:Cost per watt chart? (0)

Anonymous Coward | more than 3 years ago | (#33116944)

How is The Futurist 'in the industry'? Hardly one or two articles on that whole site are about solar. He posts on subjects as diverse as astronomy to artificial intelligence to fighting against feminism, for gods sakes.

Re:Cost per watt chart? (1)

sheepofblue (1106227) | more than 3 years ago | (#33114612)

Sorry I left it in the glove box of my flying car

Re:Cost per watt chart? (0)

Anonymous Coward | more than 3 years ago | (#33115124)

While you are at, can you post a cost per kg chart over carbon fiber?

Re:Cost per watt chart? (1)

Doc Ruby (173196) | more than 3 years ago | (#33115154)

Solarbuzz publishes an updated graph of $:W-peak [solarbuzz.com] in its monthly reports of solar PV module prices. The data comes from its own proprietary market research (which it sells in detail).

You can see that solar module prices are falling steadily, as they were until the Bush Bubble pushed them back up and held them steady until the Bush Crash let them drop again. We finally got back in 2010 to the lows we'd left in 2004, but the drop is leveling off again. Also note that those numbers are the average market price, including all variable features. The lowest price is now $1.07:W for a 55W thin film module. Total installed price is about 2x the module price.

Re:Cost per watt chart? (4, Informative)

buback (144189) | more than 3 years ago | (#33115560)

Solar array costs per watt have dropped considerably, but an array still costs an arm and a leg.

here are some reasons:
- Enough batteries to keep your freezer frozen through the night and maybe a couple cloudy days is expensive.
- Labor costs of installation are 25-50% of installation costs, but if you don't get it installed and inspected by the proper people, your home owners insurance will probably be canceled.
- It's very expensive to install enough panels to power multiple computers, multiple TV's, ACs, Fridges, Microwaves, and a multitude of other electronic devices. Customers need to reduce their power consumption before investing in a solar array.
- Tying your solar array into the grid is expensive. you can't just dump power into the grid. it has to be clean and in phase with grid power, and has to be installed by a certified electrician. (btw it's not just THE grid, it's the power companies grid. They tell you when you can use it. If the power goes down in your neighborhood they will turn off your inverter, because they need the lines powered down when the linemen are working on them.)

Labor costs are not going to go down drastically, so i don't know how much cheaper it can get to the end user. in addition, it seems that as panel costs go down, Inverters are getting more user-friendly, and hence more complex and expensive. inverters alone run from $5000 to $8000 these days.

Re:Cost per watt chart? (1)

mattack2 (1165421) | more than 3 years ago | (#33116464)

You don't need batteries, just use the grid. Yes, I know you listed connecting to the grid as one of the expenses.

Re:Cost per watt chart? (1)

spitzak (4019) | more than 3 years ago | (#33117676)

Gosh, I have to BOTH buy batteries AND pay for the grid connection! Yea solar really is expensive when you lie.

Most electricity is just moving heat. (2, Informative)

Colin Smith (2679) | more than 3 years ago | (#33117878)

Somewhere around 60% of our electricity usage is simply moving heat around. Either producing it where it's cold or removing it when it's hot. There are far more efficient and cheaper ways to do this.

http://www.eia.doe.gov/emeu/reps/enduse/er01_us.html [doe.gov]

Stop the heat moving; insulate everything. Internal and external walls. Roofs, floors, refrigerators/freezers. If not vacuum panels, research into the production of really cheap aerogels for building, DIY materials and domestic devices would probably do more to reduce electricity usage and bills than solar panels.

 

Re:Cost per watt chart? (0)

Anonymous Coward | more than 3 years ago | (#33119186)

You are out of touch. It costs $20k for aUS home with the correct roof orientation. Solar is cheap. In fact, it has a solidly most predictable cost over its lifetime compared to ANY other power source. This is mainly due to the impending politics, developing global energy problems, and their impact on fuel prices. Similarly, competing alternatives such as large hydro and nuclear are more sensitive to other issues. The present status quo represents the worse case scenario for solar, which presently returns about 6-8% annualized return over 20yr for 20% of single family U.S. dwellings. The catch is the long commitment.

More senseless, useless hot air... (1, Insightful)

Anonymous Coward | more than 3 years ago | (#33114214)

Bring a product to market with all your so-called cheap abundant technology that never seems to pan out. I'm getting pretty damned tired of hearing about all these "advances" when nothing ever comes of it.

good tech is available, money is not (1)

nido (102070) | more than 3 years ago | (#33114486)

With hydrocarbons, energy consumers pay for their energy a little at a time. With clean technologies, a large up-front investment is made, which pays for itself over a period of many years.

Most energy consumers can't afford the initial cost... And if they get a loan, interest costs eat up any savings that they might have gotten.

One small engineering advancement will make the energy companies obsolete.

Re:good tech is available, money is not (1)

Jeremi (14640) | more than 3 years ago | (#33118466)

Most energy consumers can't afford the initial cost... And if they get a loan, interest costs eat up any savings that they might have gotten.

Actually, there is a solution to this problem... the Power Purchase Agreement [wikipedia.org] . It allows consumers to get a solar power system installed without having to put any money down, or pay any interest. You basically sign the agreement, let the company install the equipment, and then enjoy an instant, permanent decrease in your electric bill. My building is having a system installed this way this year, we expect to see a 35% decrees in our electrical costs, "for free".

Re:More senseless, useless hot air... (2, Interesting)

skids (119237) | more than 3 years ago | (#33114706)

CSPV cells are one of the tech items that do in fact come to market. EMCOR and Spectrolab and others like Ammonix routinely bump their efficiency with new processes -- not just the efficiency of their "champion cells" but of their normal end product. In fact there have been upgrades done to concentrating PV plants whereby just by replacing the cells/heatsink, leaving all the dishes or whatnot untouched, they have increased output of the plant.

I feel like someone let my jet-pack fall out the back of the UPS truck, too, but not in this particular sub-area of solar PV.

Not for home use (2, Insightful)

Anonymous Coward | more than 3 years ago | (#33114220)

This is not intended for home/standard use. See below:

From the article:

While most silicon solar cells have been rendered inert by the time the temperature reaches 100 degrees Celsius, the PETE device doesn't hit peak efficiency until it is well over 200 C.

Because PETE performs best at temperatures well in excess of what a rooftop solar panel would reach, the devices will work best in solar concentrators such as parabolic dishes, which can get as hot as 800 C.

Meaningless Comparison (1)

pavon (30274) | more than 3 years ago | (#33114250)

Because PETE performs best at temperatures well in excess of what a rooftop solar panel would reach, the devices will work best in solar concentrators such as parabolic dishes, which can get as hot as 800 C. Dishes are used in large solar farms similar to those proposed for the Mojave Desert in Southern California and usually include a thermal conversion mechanism as part of their design, which offers another opportunity for PETE to help generate electricity as well as minimize costs by meshing with existing technology.

The fact that it is twice as efficient as a PV system is completely irrelevant, given that it will be competing with solar concentrators not PV systems.

Re:Meaningless Comparison (1)

FooAtWFU (699187) | more than 3 years ago | (#33114376)

The fact that it is twice as efficient as a PV system is completely irrelevant, given that it will be competing with solar concentrators not PV systems.

That depends on whether it can be deployed on a smaller scale or with different resource constraints than a regular solar concentrator. The standard solar-concentrator of an array of mirrors pointed at a central tower takes a certain amount of space, and there considerations about how the typically steam-powered generation process using that heat uses water (which is scarce enough in places like Arizona that some have decried solar energy plans as mandating unsustainable water exports). The alternative to that at present is, in fact, PV or solar chimneys.

Now, if you could put up a single parabolic mirror that focuses on one of these, small scattered deployments on random hillsides or flat rooftops might still be feasible, and would have a footprint similar to a windmill (with fewer concerns about noise and dead birds). It's just not going to sit on top of the average attic.

Re:Meaningless Comparison (3, Informative)

joggle (594025) | more than 3 years ago | (#33114448)

Continue reading:

Melosh calculates the PETE process can get to 50 percent efficiency or more under solar concentration, but if combined with a thermal conversion cycle, could reach 55 or even 60 percent – almost triple the efficiency of existing systems.

Cool, I mean, hot. (0)

Anonymous Coward | more than 3 years ago | (#33114266)

Possibly one could try using a small panel surface with a lens pointing to it (if lenses are cost effective in this scenario) so even places up north could benefit. Way interesting.

So, is this like... (2, Funny)

kainosnous (1753770) | more than 3 years ago | (#33114270)

pointing a magnifying glass at an ant? I call prior art!

Interesting, but not yet practical (1, Informative)

mark-t (151149) | more than 3 years ago | (#33114278)

I get the impression from the article that this tech would be impractical outside of situations where parabolic mirrors are not being used to focus the sun's energy onto such a solar cell. That makes it mostly impractical for everyday use.

Re:Interesting, but not yet practical (4, Insightful)

Chris Burke (6130) | more than 3 years ago | (#33114664)

Impractical for personal residence deployment and use, but I'd certainly call a big solar power generation station providing energy "everyday use". Or at least, I'd like for it to be an everyday use. Much like efficient windmills are much too large for my backyard, yet provide me with clean energy everyday.

You wimp... (0)

Anonymous Coward | more than 3 years ago | (#33115990)

just build a hydroelectric dam in your backyard like I did, everyone knows relying on the grid isn't practical for everyday use.

Re:Interesting, but not yet practical (2, Informative)

budgenator (254554) | more than 3 years ago | (#33116450)

Not necessarily, parabolic trough [wikipedia.org] concentrators aren't that exotic, there are many DIY [youtube.com] examples on youtube.

When will these ever make it to market (2, Insightful)

Kagato (116051) | more than 3 years ago | (#33114292)

It seems like every 6 months there's some big breakthrough in Solar that will make it many times better than existing technology. As far as I can tell none of it ever makes it out of the lab and into the market.

Re:When will these ever make it to market (2, Funny)

hesaigo999ca (786966) | more than 3 years ago | (#33114516)

They all get bought out by the oil companies to keep it hidden and hush hush and then shelf the projects...same thing happened with those water powered motors that we are not supposed to know exists but have been shelved a long time ago...wiki i think has the links...

Re:When will these ever make it to market (1)

LongearedBat (1665481) | more than 3 years ago | (#33119502)

How can any water powered motor work without conflicting with the first law of thermodynamics?
From what I understand, both fuel and exhaust would be the same... water. Probably the same amount of it too. That sounds very much like free energy to me.

Don't get me wrong... I would really love for any type of water powered motor to work for real. (There appear to be several types.) But I've had a look around, and can't find any links describing the theory or science behind any type of water powered motor.

Re:When will these ever make it to market (5, Informative)

tgd (2822) | more than 3 years ago | (#33114528)

Actually lots of it has. PV arrays are far more efficient now than even ten years ago, and the technologies around heat-based concentrators is also far advanced. There are parts of the country where its affordable to run a house entirely off solar -- something not possible a decade ago.

Just because the whole world hasn't converted doesn't mean the innovations aren't making it to the market, it just means even doubling efficiency hasn't helped make it cheaper than oil.

Re:When will these ever make it to market (3, Informative)

jellomizer (103300) | more than 3 years ago | (#33114538)

There is a big gap between lab results and making a product out of it.

1. There is the price to produce.
2. Are the materials robust enough for real life.
3. Is the research funded by an organization who will actually give it to industry. Oddly enough there are some groups who are so Anti-Business after there research is done they don't want to sell it to a big company as they would be selling out.
4. Can the technology be reproducible.
5. Is it safe.

There are a lot of details to be worked out.

I agree (1)

vinn (4370) | more than 3 years ago | (#33114546)

I agree. I was going to reply and say the exact same thing. I'm sick of hearing about solar breakthroughs because nothing has been done to make this technology both affordable and practical for a homeowner. I live in one of the better parts of the country for solar power, and an installation would cost more than $15,000 to even begin to be practical.

I'd love to find a conspiracy theory in this, such as oil companies purchasing the patents and never developing the technology. Sadly though, I suspect much of it can be attributed to overzealous researchers who don't understand practical manufacturing, deployment and maintenance concerns.

Re:I agree (5, Insightful)

qoncept (599709) | more than 3 years ago | (#33114840)

These "overzealous" researchers are, in your overarching lump sum, the same people who create new technologies that do make it to market. You know for every new technology that makes it, there are several that don't. Is your solution to stop all the research so all the failures will stop breaking your heart?

I live in one of the better parts of the country for solar power, and an installation would cost more than $15,000 to even begin to be practical.

What part of the country is this where putting 15 grand in to your house is such an outrageous sum? A new roof, HVAC, siding, remodeling a room.. pretty much anything you do to your house is going to have a similar cost. And I guarantee none of them would give you the same return until you sell the house.

Re:I agree (1)

ooshna (1654125) | more than 3 years ago | (#33115130)

As dumb as this might sound my old neighbor had a coworker who created an engine that ran off water. The guy sold the patent to some company that was into oil for a few mil and it disappeared. It could be a bullshit story but my neighbor wasn't one to make things up and said it so matter of factly. Then of course are the youtube videos of things like this [youtube.com] (and to add to the conspiracy theory aspect of it if you search google it seems he died in a 'chemical accident')

Re:I agree (1)

jusdisgi (617863) | more than 3 years ago | (#33115458)

As dumb as this might sound my old neighbor had a coworker who created an engine that ran off water.

No he didn't. But you're right about one thing: that sounds really dumb to anyone who knows even the slightest bit of chemistry. Don't take my word for it. [wikipedia.org]

Re:I agree (1)

Jeremi (14640) | more than 3 years ago | (#33118368)

But you're right about one thing: [an engine that ran off water] sounds really dumb to anyone who knows even the slightest bit of chemistry

It's quite doable, actually. All you need is a Nissan Leaf and the Hoover Dam. Presto, a car powered by water!

Re:When will these ever make it to market (1)

MadUndergrad (950779) | more than 3 years ago | (#33114826)

It looks like they could use this to retrofit current or proposed solar thermal installations. They're talking solar concentrators and temperatures well over 200C + combined cycle, so it would probably be a pretty minor change on the whole.

Re:When will these ever make it to market (0)

Anonymous Coward | more than 3 years ago | (#33114844)

normally id agree, but in this case i do not. I rember when they where talking about how they can now mass produce solar pannels, few years later....little kits are all over the internet for a decent price and its going down.

Re:When will these ever make it to market (1)

Surt (22457) | more than 3 years ago | (#33117396)

What you can realistically buy to stick on your house has gone from about 14% to 20% efficiency over the last couple of decades. That's about 50% improvement.

Re:When will these ever make it to market (1)

drolli (522659) | more than 3 years ago | (#33118646)

In average from the Nature paper to you being able to buy it in the store it should be usually 5-15 years, if its applied research. 5y is unlikely (developing and testing an industrialized process for thin film technology wiht composite technologies takes easily 2-3 years) and if its going to be more than 15y it may mean that it is to difficult, to expensive or has some other disadvantage - or something else is better.

50% conversion! (1)

icebike (68054) | more than 3 years ago | (#33114302)

While most silicon solar cells have been rendered inert by the time the temperature reaches 100 degrees Celsius, the PETE device doesn't hit peak efficiency until it is well over 200 C.

Because PETE performs best at temperatures well in excess of what a rooftop solar panel would reach, the devices will work best in solar concentrators such as parabolic dishes, which can get as hot as 800 C.

So still not practical for home roof top deployment. Most people will not want 800C )or anything close) on their roof tops even if it was light and portable.

Solar concentration requires big expensive equipment - Mirrors or Lenses.

If they could find a way to push this technology into the 100-150 degree range (thereby eliminating the need for concentration) and STILL maintain the 50% energy extraction the potential benefits are huge.

Re:50% conversion! (1)

dch24 (904899) | more than 3 years ago | (#33114324)

Hey, reply to my post above. They're targetting 200 C for now. That's definitely doable on a rooftop, though not quite as safe as 100 C.

Re:50% conversion! (0)

Anonymous Coward | more than 3 years ago | (#33114350)

You consider a rooftop that's hot enough to boil water safe?

Re:50% conversion! (1)

dch24 (904899) | more than 3 years ago | (#33114362)

You consider "not quite as safe" == "safe" ?

Re:50% conversion! (1)

Anon-Admin (443764) | more than 3 years ago | (#33114422)

Mine is that hot here in Texas. lol

Re:50% conversion! (3, Interesting)

icebike (68054) | more than 3 years ago | (#33114456)

Roof top glass enclosures (solar hot water) nearly achieve this all by themselves in some sunny locations. http://en.wikipedia.org/wiki/Solar_thermal_collector [wikipedia.org]

Its contained in the collector. Its so hot you generally have to mix with cold water for household use.

Re:50% conversion! (1)

tgd (2822) | more than 3 years ago | (#33114550)

Temperatures near 100C aren't all that uncommon in hot climates on dark roofs.

And 200C in a controlled collector is no less safe than 100C spread over an entire roof -- both are below the combustion point of anything else on the roof.

Re:50% conversion! (1)

cusco (717999) | more than 3 years ago | (#33116048)

You've obviously never actually installed a roof, have you? It's not uncommon for the temperatures on the roof to be 50+ degrees higher than on the ground. New roofers die frequently because they don't realize that it's possible to sweat out water faster than their stomach can absorb. If the temperature in Phoenix is already 100 degrees on the ground it's not going to need a big temperature boost to bring it up to their desired temperature.

Re:50% conversion! (0)

Anonymous Coward | more than 3 years ago | (#33117398)

The record for Phoenix is about 50c, set in 1990. You think going on the roof is going to double it?

Re:50% conversion! (2, Funny)

chill (34294) | more than 3 years ago | (#33114522)

o still not practical for home roof top deployment. Most people will not want 800C )or anything close) on their roof tops even if it was light and portable.

Are you kidding? Add a couple of rotating mirrors and market it as a death ray. Rabbits getting into your garden? Neighbor's dog crapping on your lawn? Reflect that beam spot around and *poof*, no more problem!

Re:50% conversion! (0)

Anonymous Coward | more than 3 years ago | (#33116822)

o still not practical for home roof top deployment. Most people will not want 800C )or anything close) on their roof tops even if it was light and portable.

Are you kidding? Add a couple of rotating mirrors and market it as a death ray. Rabbits getting into your garden? Neighbor's dog crapping on your lawn? Reflect that beam spot around and *poof*, no more problem!

Yes, my dog... *backs away*

Re:50% conversion! (0)

Anonymous Coward | more than 3 years ago | (#33115052)

So still not practical for home roof top deployment. Most people will not want 800C )or anything close) on their roof tops even if it was light and portable.

I am fairly sure the flames in the natural gas heating furnace on my home's roof reach temperatures in the 800C range. So do the flames on the fireplace inside my house, and the coils in the electric cooking oven also inside the house. How about candles, cigarettes, BBQ grill? 800C is nothing special on any modern home.

mirrors don't have to be expensive. (1)

Colin Smith (2679) | more than 3 years ago | (#33115278)

They also don't have to be big. Fresnel reflector for example. Bog standard flat mirrors, arranged such that they reflect onto a focal point. Make the mirrors out of perspex and it's cheap and light as well as easily fitting onto a roof. You get a large mirror with a low profile, and can almost put the focus where you like.

Amazing. (-1, Troll)

Anonymous Coward | more than 3 years ago | (#33114304)

A 'breakthrough' in solar power generation. We've only been having those for about a hundred years. Yeah.

Obligatory (-1, Offtopic)

BabyDuckHat (1503839) | more than 3 years ago | (#33114364)

One of the cartoons on this site [xkcd.com] may apply to this story in a humorous and eerily prescient manner.

compete with what, now? (4, Insightful)

Tumbleweed (3706) | more than 3 years ago | (#33114384)

Compete with oil? I'm going to guess that they mean with coal, as oil is rarely used as a fuel for power generating stations. Coal and natural gas, yeah, oil - not so much. In the U.S., anyway, only around 1% is generated by petroleum, whereas coal is about 45% and natural gas is about 23%.

Re:compete with what, now? (1)

orange47 (1519059) | more than 3 years ago | (#33114510)

maybe they mean in solar powered cars..

Re:compete with what, now? (1)

jusdisgi (617863) | more than 3 years ago | (#33115510)

Unless by "solar powered cars" they mean "electric cars attached to a solar-powered grid" that's pretty much exactly as stupid as the idea of a grid technology competing with oil. Cars don't have anywhere near enough surface area to produce useful energy, even if we didn't park them in garages all the time.

Re:compete with what, now? (0)

Anonymous Coward | more than 3 years ago | (#33114544)

And in eastern Canada, hydro-electricity is generating above 80% of our needs, even generating electricity for the north-eastern USA states in some cases.

Re:compete with what, now? (3, Informative)

Tumbleweed (3706) | more than 3 years ago | (#33114634)

And in eastern Canada, hydro-electricity is generating above 80% of our needs, even generating electricity for the north-eastern USA states in some cases.

Here in Seattle, we're at almost 89% via hydro, nuclear at over 5.6%, and wind at over 3.4%. We're like at 2% or so (at least as of 2008) for coal & natural gas combined; that's well beyond what even I had thought for our area.

More likne (1, Informative)

Anonymous Coward | more than 3 years ago | (#33118092)

To correct the gp : In the Quebec province (Eastern Canada) as of 2008 : 95.6% of electricity is from hydroelectric sources.... and climbing. (Source Wikipedia)

Re:compete with what, now? (1)

DerekLyons (302214) | more than 3 years ago | (#33114928)

Plug-in electrics and hybrids will eventually replace straight hybrids - so a comparison with oil is not entirely unfounded. Premature maybe, but not far fetched.

Re:compete with what, now? (1)

drinkypoo (153816) | more than 3 years ago | (#33115324)

Compete with oil? I'm going to guess that they mean with coal, as oil is rarely used as a fuel for power generating stations

There's an awful lot of power generated all over the place (in stationary installations, mind you) with oil and with diesel. Furthermore, most of these are very dirty because they are small and it is actually more difficult to control the emissions in such a system. Of course, mostly we don't control emissions anyway, unless they have obvious effects.

Re:compete with what, now? (1)

tronbradia (961235) | more than 3 years ago | (#33119500)

You may be right technically, but in the long run, oil competes with all other energy sources. The reason we drive around in gasoline-consuming cars is because it's more efficient to carry around gasoline as an energy source than juiced-up batteries or hydrogen derived from electricity from the grid. If electricity became very cheap to generate thanks to solar power, and oil became more expensive due to scarcity, it would make more sense to use fuel cells or batteries as the power storage medium, obviating the need for oil as an energy source in most cases (although of course it will still be important for plastics).

No one thought to do this before? (1)

ohiovr (1859814) | more than 3 years ago | (#33114598)

Take a solar cell and slap one of these babies on it http://www.johnsonems.com/?q=node/2 [johnsonems.com]

Sadly, uneconomic (4, Informative)

Kupfernigk (1190345) | more than 3 years ago | (#33114838)

Thermoelectric looks obvious, doesn't it? A few years ago I thought how convenient it would be to use the waste heat from my Diesel boat heater to generate electric power, and I contacted a manufacturer. The reply I got was "we're not even going to quote you because it's insanely expensive". Apparently thermoelectric generators are so expensive they only make sense on things like trans-Siberian or Alaskan gas pipeline monitors, where there isn't enough light for a solar PV supply and the cost of miles of environmentally resistant wiring would be even more prohibitive. Although Peltier generators are cheap, they are hugely inefficient - and even more inefficient in reverse. It would have been cheaper to cover the entire deck in solar panels.

Re:Sadly, uneconomic (1, Informative)

Anonymous Coward | more than 3 years ago | (#33115296)

You're absolutely right, current thermoelectric power sucks. Photon enhanced thermionic emission is much, much, much more efficient than seebeck effect conversion (which is what you mean when you say peltier).

Re:Sadly, uneconomic (2, Informative)

ohiovr (1859814) | more than 3 years ago | (#33116070)

Johnson Thermo-Electrochemical Converter System isn't a peltier type device. An excerpt from the link: "The JTEC is an all solid-state engine that operates on the Ericsson cycle. Equivalent to Carnot, the Ericsson cycle offers the maximum theoretical efficiency available from an engine operating between two temperatures" Carnot like efficiency is pretty amazing for a solid state device. Hell for any device... Of course, even though it may be more efficient, it doesn't automatically make it more economical.

Just another "look at me" from a university PR (1, Informative)

Anonymous Coward | more than 3 years ago | (#33114680)

They aren't the only ones working on this process, I know a few others. Also, thermal and PV processes have been combined successfully before, unlike the claim in TFA - my own work centers on CPVT (Concentrating PV/Thermal) collectors. You can reach 40-50% efficiency like that. (Hell, you can get close to 30% just with triple-junction PV).

Look for papers by Abraham Kribus if you're into it.

Oh noes! another solar panel breakthrough (0, Troll)

GodfatherofSoul (174979) | more than 3 years ago | (#33114718)

Reading these stories is like getting my ass beat by a dominatrix, then discovering I've forgotten the "safe" word. Hey, it was cool when you started but it's not fun anymore. Seriously. Please stop.

Re:Oh noes! another solar panel breakthrough (1)

Jeremi (14640) | more than 3 years ago | (#33118494)

Seriously. Please stop.

You know what? You like it. Otherwise you wouldn't keep reading the articles, or coming back to bitch about having to read them. If you don't like the articles, there are a million other web sites you could be reading instead.

Translucent solar panels? (4, Interesting)

2obvious4u (871996) | more than 3 years ago | (#33114740)

So if you could reflect the heat to generate power and use photovoltaics to generate power, could you also create them translucent to some spectrum of light? Then you could grow crops under the solar array, use the array for water capture so the irrigation would hold water better and provide power and temperature maintenance. This idea only works if photovoltaics and plants uses different spectrum to generate power/photosynthesize.

Re:Translucent solar panels? (2, Interesting)

zero0ne (1309517) | more than 3 years ago | (#33114846)

Very interesting Idea:

Here is a link to start it off: http://digitalgardening.com/blog [digitalgardening.com]

Its a new month (1, Interesting)

Anonymous Coward | more than 3 years ago | (#33114822)

Its a new month. Along with the new month comes the "Latest and Greatest" in solar power innovation, this one far far more revolutionary than last months... We had electron dots, last month, we had microscopic cones capturing UV as well as thermal a few months before..... I go to the store and am looking at 25 year old technology. I know 'to market' is the hard part, but at what point will all of this innovation, magic and wonder actually be ready to buy? Is it like Tokamak reactors, 30 years for sure, and at any time in its 60 year history, there wasn't a month that went by when it was only another 30 years or 'just 30 more years for sure'. Unfortunately it was a relativistic estimate. As you get closer to a firm, fixed date, time slows down. In time that can be perceived, its always 30 years. Its almost like one of Zenos paradoxes. Hello solar, we will all be using you, some time in the one-of-many-possible future universes.

Compete? (1)

DoofusOfDeath (636671) | more than 3 years ago | (#33115160)

that could make solar power production more than twice as efficient as existing methods and potentially cheap enough to compete with oil.

Do you mean compete with oil's fair-market price, or the price after all the subsidies that the U.S. government supplies for oil production, including the military cost?

It's all for VC money (2, Interesting)

tekrat (242117) | more than 3 years ago | (#33115378)

This seems to be the new scam for this decade. Your company/university/research-lab accounces a "breakthrough" using commonly available, cheap materials that "somehow" provide energy because the arrangement of these materials is the part no one has thought of before.

We've got: EEstor with their "ultracapacitor", Bloom Energy with the "Bloombox", Stanford's now got their Solar Gen whatever it is, there's the Science Fair Kid that made a 30% increase in PV efficiency, yadda yadda... Hell, a few weeks back even the Chinese announced a "new solar product" that was supposed to be more efficient...

Someone should go through the last 5 years of Slashdot and pull up all the articles about new energy technology and where they announce it will be available in stores in 5 years time, and let's see what the claims are versus what reality has brought us.

Because so far, all I ever see in stores or online is the same old crap that's been available since forever, plain old 12% efficient silicon-based PV panels, where you still need $2000 worth of them to run a fridge.

Re:It's all for VC money (4, Insightful)

jusdisgi (617863) | more than 3 years ago | (#33115592)

Recent grid solar installations are far more efficient and cost-effective than their counterparts from five years ago. I'd say that suggests all this research is going somewhere. What, you thought that each of these announcements about laboratory successes would instantly result in a new product on the shelf of your local Wal-Mart?

Re:It's all for VC money (2, Informative)

pspahn (1175617) | more than 3 years ago | (#33116328)

What, you thought that each of these announcements about laboratory successes would instantly result in a new product on the shelf of your local Wal-Mart?

Seeing as they expected someone else to go gather all the data proposed, I would say yes.

Re:It's all for VC money (0)

Anonymous Coward | more than 3 years ago | (#33117094)

I'm not sure what you mean by that... the Melosh group is definitely collecting their own data (and this can be seen in the nature paper).

This tech could be built into solar water heaters (1)

Anonymous Bullard (62082) | more than 3 years ago | (#33119210)

"Solar water heating [wikipedia.org] or solar hot water is water heated by the use of solar energy. Solar water heating systems are generally composed of solar thermal collectors, a water storage tank or another point of usage, interconnecting pipes and a fluid system to move the heat from the collector to the tank. This thermodynamic approach is distinct from semiconductor photovoltaic (PV) cells that generate electricity from light; solar water heating deals with the direct heating of liquids by the sun where no electricity is directly generated."

Basic glass-covered box + copper pipes (flattened inside the black-painted floor of the box) + water collection barrel combo has long been an important alternative technology feature in the developing world.

So soon one could tack one of these new-fangled Stanford solar/heat panels at the bottom of the box and besides photon conversion also harness the high temperatures for increased electricity generation.

I truly hope that this tech doesn't become a patent pissing contest but it is made available and even manufactured around the world without licensing impediments. Maybe the world's governments could step in, enumerate the inventors appropriately and make sure these crucial technology alternatives to fossil fuels become widely available and in massive quantities.

Repeat after me (1)

rkinch (608630) | more than 3 years ago | (#33119468)

Beware the "radiant heat" fallacy.

The solar flux consists of electromagnetic radiation. Electromagnetic radiation is not heat. The sun does not radiate heat.

This novelty looks remarkably like just adding a thermocouple, which has never been any good at turning heat into electricity.

Load More Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Create a Slashdot Account

Loading...