What is Digg?104 Comments
- Djerrid, on 10/11/2007, -1/+174"Open land"? Who needs open land when you have hundred's of square miles of roofs to put these solar cells on?
- EntropyMan, on 10/11/2007, -11/+172I don't get the people who think energy is scarce. We have the most plentiful energy source available to us for as long as we need it, with enough power per millisecond to feed the entire US, while using up very little of this nation's most abundant resource -- open land.
If we ever decided to subsidize solar to the extent we subsidize coal and oil (to the tune of a trillion dollar war), the only energy problem we'd have is having TOO MUCH and deciding how to sell it.
If we get to the point where electric cars and electric homes are the biggest contributor to global warming (via pure heat loss), then I'd call that a whopping success. Because everything else would have simply gone away. - geminitojanus, on 10/11/2007, -1/+84These cells are absolutely brilliant engineering at work. They act like single P-N junction solar photo-diodes, except they have three different stacked material layers, each with a decreasing band-gap to absorb the fast-moving photons first, then absorb the rest further down the stack. The biggest news here is the development of the new material stack (which is a blend of Gallium Indium Phosphide, followed by Gallium Indium Arsenide, built on a common substrate of Germanium). These are built by applying thin film substrates directly on top of the previous substrates, making these solar cells three-dimensional semiconductors (even if they are fairly simple rows of photodiodes). These are also very atypical semiconductors, as both InGaP and InGaAs have very large (tunable) band gaps, and a high degree of electron mobility (which means higher voltages, and faster switching when used to create transistors; Indium and Gallium compounds (especially GaAs) have the highest known electron mobilities of any material, allowing us to create XXXGHz transistors).
The biggest problem right now is that these devices need really sophisticated manufacturing equipment (one process known as Molecular Beam Epitaxy (MBE), another important process known as MetalOrganic Vapor Phase Epitaxy (MOVPE)) in order to attach/grow the materials to/on their substrates and to make the diodes. This, combined with the exotic metals and semiconductors makes them quite expensive to manufacture, but with economies of scale and the price of MBE machines coming down due to blue laser manufacturing (BluRay/HDDVD), and MOVPE prices coming way down due to the usage of them in LCD and high-speed RF device (WiFi/WiMax/Bluetooth basebands) manufacturing, they should be more economical in the future. [Note, these machines are still fairly slow, so the rate of production will only increase by increasing the number of machines you have on your production line].
Great science, but it'll be quite a while before we see them crop up into general usage (especially as this is a Boeing subsidiary, which means Defense contracts which means bloated budgets and so on and so forth). - ryanknapper, on 10/11/2007, -9/+87hdtvdust: I mod you down just for being an *****. When you come across as an ***** it doesn't matter if you're right.
- citrusfizz, on 10/11/2007, -12/+59@ hdtvdust
dude, change your tampon. Don't be such a jerk and maybe you wont get buried. - Scyth3, on 10/11/2007, -5/+40I dugg you up just because you must know what you're talking about with those crazy scientific words of yours. :)
- rollem, on 10/11/2007, -1/+31hdtvdust: You're buried because you're being being unnecessarily caustic. Solar is obviously subsidized to some extent, but don't you think that more research would result in more efficient solar technologies. Finally, the solar cells used by NASA are much more efficient but cost significantly more. It's not just a grandiose, unsubstantiated statement.
- EntropyMan, on 10/11/2007, -6/+36It's very amusing. I've got hdtv on my ban list, so I only get to see your reactions to his rants. You should all try it sometime -- but let me know if there's something I should really slam him for. Otherwise, it's not worth my time.
- CaptMonkey, on 10/11/2007, -2/+29It's not that energy is scarce, it's more that energy in cheap and easy-to-use forms is scarce. Nothing tops oil as far as portability, ease and low cost of getting it out of the ground, and that it packs a bunch of energy in a small package that can easily be exploited. You can easily get fuel from renewable sources, but it's going to be more expensive and harder to get the amount that you need. And with more expensive energy, comes more expensive everything. All of the stuff that you buy at a store needs energy for transport, storage, and production. When energy costs go up, so will the price of food, consumer goods, clothes, everything. Energy is going to be a huge problem that we need to tackle soon, but our politicians are too busy having hearings on trivial issues like steroid use in baseball and copyright infringment.
- DrDragun, on 10/11/2007, -4/+30the problem is that solar cells require rare heavy metals to produce en masse, of which the world is already seeing a shortage. Cadmium, Tantalum, Indium... all used heavily in electronics and all approaching critical shortages in the first half of the next century:
http://www.my-esm.com/showArticle.jhtml?articleID=199703926
Solar is an awesome dream because it is 100% clean and 100% renewable, however the world still isn't ready economically to make such a radical change. Plus, it's like wind in that it is spiky and erratic generation of power, and so you have to install "batteries" to keep the grid up through the night. The most effective way is with a pumped hydro facility (http://en.wikipedia.org/wiki/Raccoon_Mountain_Pumped-Storage_Plant) but this is terrain dependent.
I think a more realistic approach to clean energy is biodiesel to start. It requires a minimal change to existing infrastructure (you can use normal gas stations and very little modification to existing diesel vehicles / facilities) and the process is nearly carbon-neutral (emissions are countered by photosynthesis growing the crops). Critics of biodiesel say corn feedstock is not sustainable or economic... but check out the new stuff they are doing with algae. Algae can be 100x as productive as corn per acre by using shallow ponds, and you can grow it in sewage water to replace waste treatment plants, killing 2 environmental problems with 1 stone. - diggydougie, on 10/11/2007, -0/+25The efficiency is only half of the battle. The other half is price. I know that this is still in the lab, but is it manufacturable?
- betacmag4u, on 10/11/2007, -1/+21http://www.otherpower.com/otherpower_solar_new.html
A SOLAR POWER MYTH
We've often heard the myth that "it takes more electricity to manufacture a solar panel than it will ever put out." This is simply not true...this myth may have started during the Ronald Reagan era. This is of course a very difficult statistic to calculate, but according to the National Renewable Energy Laboratory in Golden, CO, a study has been done to answer the question. The study found that single-crystal panels reach the energy payback point in 5-10 years, polycrystalline panels in 3-5 years, and amorphous silicon panels in 0.5-2 years. Be advised that because the question is so vague, there is a large margin of error for these figures! We just discovered a recent, very detailed study about solar panel energy payback time in the January 2001 issue of Home Power magazine. This study, by Karl Knapp, PhD, and Teresa Jester, finds payback time for a standard module to be about 3.3 years, and 1.8 years on a thin-film panel. The study factors in energy costs for ALL parts of the panel and manufacturing process. - Witchboy, on 10/11/2007, -0/+20I believe we should work toward putting a solar panel on every roof, commercial or private. Besides taking advantage of a great resource (the sun), it's clean and imagine the new revenue/small business it would generate. The cost of doing it is much, much smaller than the costs we'll face in the future if we continue to rely on oil and coal.
@hdtvdust
Ah, but he didn't *say* that we don't subsidize solar. He said that we don't subsidize it "to the extent we subsidize coal and oil." So you're wrong. - chaesar, on 10/11/2007, -1/+19http://www.sciencedaily.com/upi/index.php?feed=Science&article=UPI-1-20070523-13025700-bc-us-solarenergy.xml
22.7 million dollars for solar power research. That is all.
http://www.fee.org/publications/the-freeman/article.asp?aid=3782
"The Department of Education spent $34 million supposedly helping Americans become better shoppers and homemakers." - stinkypyper, on 10/11/2007, -0/+18@Entropyman
Exactly! We are covered in the stuff. This map: http://en.wikipedia.org/wiki/Image:Solar_land_area.png shows how much of the earths surface would have to be covered with solar panels with an 8% efficiency to handle ALL of the worlds energy needs for everything. Now divide that surface area by 5. If we just used wasted roof space on buildings we wouldn't need to wreck any more land. Toss in wind generation and some clean hydroelectric and we're done.
I still wonder why the hell we bother even air conditioning or heating are houses when the ground just feet below surface level is a stable temperature year round. - RicktheBrick, on 10/11/2007, -0/+14When will we get a phone call from the local power company asking to come to my house in order to install these solar collectors on my roof? When they are cost effective than they should be installed for free and paid for by paying one's normal electric bill. Satellite television and cell phones both give equipment away for service contracts so I do not see why power companies can not do the same.
- SteelChicken, on 10/11/2007, -1/+13We dont even need uber efficent solar cells...just uber cheap ones. put em on every roof. problem solved.
- EochaidRiata, on 10/11/2007, -0/+11That is a good point. Decreasing cost to $1/m^2 at 5% efficiency would be a much larger breakthrough than a 50% efficiency cell that costs $10,000/m^2.
- geekee, on 10/11/2007, -3/+11"Where will we store the power so we can use it when the sun is down?"
Pump water uphill (And then use it to turn a turbine when you want the energy)? - EntropyMan, on 10/11/2007, -0/+7I don't think solar is the only answer. But if we can switch to electric cars and only use oil for plastics and diesel and maybe an occasional nuclear plant for anywhere solar can't cover it, I think we'll be fine. It will take 10-20 years to switch over. But we're not even trying right now.
The first thing is to get solar to the point where it's cheaper, and that means ending the subsidies for oil, and even coal now. The rest will happen fairly rapidly (in the grand scheme of things) once we do that. - betacmag4u, on 10/11/2007, -0/+7@ EntropyMan .....one they roll out the infrared spectrum cells it will be a 24x7 proposition.
- inactive, on 10/11/2007, -2/+9Well, IF this was achieveable on a grand scale...which it isn't yet and not even close...it would not be as big a problem as you think. The vast majority of energy is used during daylight hours. Plus, during the evening, you are producing more than enough energy than you need, so the West could supply the east for those 3 extra hours that they have sun. Sure, there would need to be a way to store it, but not as much as you might think
- molecule, on 10/11/2007, -0/+7"each with a decreasing band-gap to absorb the fast-moving photons first,"
i think you mean greater momentum, which increases w/ frequency. all the photons are fast-moving (c). - ricree, on 10/11/2007, -2/+9"each with a decreasing band-gap to absorb the fast-moving photons first,"
The fast moving photons? - cupofjoe84, on 10/11/2007, -4/+10Charge up batteries, would be my guess.
- MWeather, on 10/11/2007, -1/+7We won't need to, since we have more than one source of energy.
- lostngone, on 10/11/2007, -1/+7Don't want to see or read about this "breakthrough", about every 3-4 years I read about some new super-duper photovoltaic technology that is going to revolutionize solar power as we know it... Well its been about 23 years since I started following solar power and I have yet to see any of these "breakthrough" technologies come to market.
- ryanknapper, on 10/11/2007, -1/+7Batteries are terrible solutions for storing electricity. Fortunately, the Sun is always shining somewhere.
- chaesar, on 10/11/2007, -0/+6http://www.whitehouse.gov/omb/budget/fy2008/energy.html Dept. of Energy 2008 Budget.
Hightlights:
385 M - Coal Research Initiative
108 M - FutureGen project (coal)
1.65 B - Coal-related tax credits
148 M - Solar research
179 M - Biofuel (retarded, people are already burning tons of plant oils in diesel engines worldwide)
81 M - Hybrids/plug-ins
309 M - Hydrogen fuel initiative - LilRabbitFooFoo, on 08/11/2008, -0/+6We could have taken the trillion we've spent on Iraq and used it to make our country PERMANENTLY immune to OPEC, which would have allowed us to leave these godforsaken deserts because we no longer need their oil, and that would have made them happy cause we'd be gone. A win win win.
Hmm, what was a better use of a trillion dollars, solar power or finally killing off an enemy we'd actually declawed a decade ago? - catalysis, on 10/11/2007, -1/+6I hate to break it to you guys, but you can't increase the surface area because the sun is a point light source. The most efficient geometry is a flat panel. This isn't an oil company conspiracy.
- MWeather, on 10/11/2007, -0/+5"They just won't tell you there's a coal plant running the entire time they were doing that and it was producing nothing at all."
Is that 100% capacity? - GGzah, on 10/11/2007, -1/+6Most cells out there should last a minimum of 20 years (the industry standard from what I have seen is a 20 year minimum warranty), and tend to show only minor decreases in output (assuming they are used constantly over that time) There are PV cells back from when they where first being used 30+ years ago, that are apparently still chugging along nicely today (I only say 'apparently' because I've never seen one that old myself, only read about them online)
Bottom line is, they last along time and continue to function at close to capacity for as long as they last. A sound long term investment! - EntropyMan, on 10/11/2007, -2/+7@DrDragun, I think it's just our government that's not ready. And as for the rare-earth elements, they can be recycled. But apart from this kind of solar cell, there are plenty that only use mirrors, steam, and a turbine. Those are quite effective, and they can be made to last practically "forever."
- Darkhacker, on 10/11/2007, -0/+5What we need to invent is a better battery. I'm sure solar panels could power the average family home, but what about at night? The extra energy from the day needs to be stored somewhere and for large amounts of power like that, batteries are very expensive. We need a way to produce cheap batteries that hold a lot of energy for their size.
- EntropyMan, on 10/11/2007, -0/+4@catalysis,
As I understand the technology here, they have in fact increased the surface area by going 3D. Some wavelengths are absorbed at the top, and different ones filter down through the stack. That would seem to put a multiplier on the effective surface area times the number and effectiveness of each layer. - jeffeb3, on 10/11/2007, -1/+5@nikokun
The slanted solar panels would not collect any more light than flat ones would. The only reason it's important to point the panels at the sun is the effective area to the sun:
this: instead of:
______ ____
| |
| |
| |
|_____| ___
Also, you're going to have a very hard time getting the power from a solar panel to effectively add power to the power running through the lines. it would be much more beneficial if people just start putting them on their own roof. When we run low on space, we will try to optimize every little nook. Right now, the best thing is to have them as close as possible to the drain as possible.
Update: well *****, the pictures don't get through the formatting... - EntropyMan, on 10/11/2007, -0/+4@magicjava, not necessarily. Batteries and other kinds of fuel cells work. Mechanical energy, as above, or even using energy to compress gas to turn a turbine at night. Organic chemistry might also work at some point -- store energy in sugar, like the body does. Right now, I agree there is a lack of infrastructure for storing energy when the sun is down. But that can be fixed.
- MutatedNantuko, on 10/11/2007, -1/+5Ronald Reagan was a starch Solar Panel enemy because it required cooperation of non-NATO countries to create the grid large enough to power all NATO countries; efficiency was the problem. So, his cabinet members in charge of Energy made the move of disapproving solar power because of threats in the midst of the Cold War. Sadly, this move of disapproval has stuck since Reagan was such a highly approved president.
- rzrshrp, on 10/11/2007, -0/+4Partial BS on the coal plant running like usual 24/7. The coal plant will only burn enough coal to cover estimated energy usage. If the energy usage isn't as high because a bunch of people are using alt energy, it won't burn as much coal. Yes they still will be burning some coal because it won't actually shut off but it doesn't want to waste their coal when no one's using the energy.
- chaesar, on 10/11/2007, -2/+5there hasn't been a "breakthrough" since they started using them to power calculators
- geminitojanus, on 10/11/2007, -0/+3"i think you mean greater momentum, which increases w/ frequency."
Thanks, it was early in the day and I didn't spend as much time reviewing the post as I should (and hell, this is Digg, someone here will correct me even if I get it wrong). High-momentum photons is exactly what I meant and was thinking, something just got lost in translation between my brain and my fingers. - jackal1291, on 10/11/2007, -0/+3As many have pointed out, the other side to getting solar feasible on a large scale is that of cost/materials. There is a ton of research happening in this area (low-cost photovoltaics) to achieve regular-PV efficiencies using cheaper and widely available metals/materials through some fundamental breakthroughs and ingenious engineering. This *will* happen, it may take some time, but the effects could be dramatic. Consider, for instance, that large swaths of the developing world (rural areas in particular) don't have regular access to electricity. However, with super-cheap PV cells we can at least provide reliable access to power in a decentralized way by having households place panels on the roofs of their houses.
This is not hype, it's a basic science and engineering problem that is incrementally getting solved. More funding will, I think, be helpful since not too many companies are willing to invest on something that's still probably a decade away from the tipping point, as it were.. - JaYBrooks, on 10/11/2007, -2/+5Then you have to count on tooling costs... Then the supply and demand thing... I remember seeing a story about a high rise building that had the fake windows converted to solar panels... Thats where this should be put first I think... Make the buildings do more than house the corporate offices..
- BobTrips, on 10/11/2007, -0/+3There's an interesting battery being developed at MIT - a "nano battery", really a super efficient capacitor.
About twice as much storage capacity per pound as a lead acid battery (very important for vehicle use), charges in under five minutes, can be discharged/recharged thousands of times.
If this thing pans out it would double the range of electric cars and make it as quick to recharge as to fill your tank with liquid fuel.
Plus it would make it feasible to store a day or two worth of power in individual houses. That would take care of the periodic availability of solar and give people some "disaster" buffering. - geminitojanus, on 10/11/2007, -0/+3"Well its been about 23 years since I started following solar power and I have yet to see any of these "breakthrough" technologies come to market."
This tech will be on the market within the year; defense contractors and satellite builders absolutely require the highest efficiency cells they can get their hands on, and don't really care so much about the volume of production or how expensive they are (especially as these particular cells are young).
Just because they're not going to hit the broader market for 10+ years, doesn't mean that these guys toiled away in a lab for absolutely no reason. The higher efficiency cells always go to Defense and Space contractors first, and they bring down the prices for the rest of us. - renrutal, on 10/11/2007, -0/+3I'm a newbie at energy conversion, so I must ask:
How do you calculate a solar cell conversion efficiency? BTW, how much efficient is photosynthesis? - geminitojanus, on 10/11/2007, -0/+3"these cells are really expensive to manufacture."
These cells in particular are really expensive to manufacture, but they also last damn well forever; we've already put very similar cells on extremely harsh environments (space, Mars) and left them there where they've operated for years non-stop under conditions that make earth look and seem like an absolute paradise.
It's worth it to drop $50k on a solar array that could power your house (and a few of your neighbors) if it's going to last 50+ years ($1k/year doesn't seem so bad now, does it?) It seems silly to me that people would skip over this (especially when house builders could easily fold it into the cost of construction, and the people living in the house can defer the part of the energy bill they're saving on paying for the array). - magicjava, on 10/11/2007, -0/+2Quote - "Partial BS on the coal plant running like usual 24/7. The coal plant will only burn enough coal to cover estimated energy usage. If the energy usage isn't as high because a bunch of people are using alt energy, it won't burn as much coal. Yes they still will be burning some coal because it won't actually shut off but it doesn't want to waste their coal when no one's using the energy."
As I mentioned above, I've been unable to find exact figures on how much coal you have to burn while your solar is running, but what you're saying seems reasonable to me. At any given time, you have to burn enough coal so the coal plant can cover usage at that time should the solar fail due to clouds, rain, etc. Another way to say this is you have to burn the same amount of coal you'd be burning without the solar plant. - grve, on 10/11/2007, -1/+3nikokun thats already being worked on - nanorods
the process needs perfecting to be viable for large scale production though
there's also work being done in replacing expensive rare metals/silicone based pv with plastic/organic materials. i think the best plastic pv are currently 3-6% effective, with nanorods it should go well into double digits. -
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