Solar Cell Achieves 40% Efficiency 632
Fysiks Wurks found on the U.S. Department of Energy website news of a breakthrough in solar energy efficiency. From the article: "...with DOE funding, a concentrator solar cell produced by Boeing-Spectrolab has recently achieved a world-record conversion efficiency of 40.7 percent, establishing a new milestone in sunlight-to-electricity performance." A page linked from Wikipedia's article on solar energy calculates the land area that would need to be covered by solar collectors at 8% efficiency to meet the world's energy needs (using 2003 figures). At 40% efficiency, it looks like a square 265 miles on a side in the American southwest would do it.
transport losses? (Score:5, Insightful)
B.
Cost is the issue (Score:1, Insightful)
Re:transport losses? (Score:3, Insightful)
How about conversion to something like hydrogen?
There are lots of desert areas that I'm sure could be used for energy generation, at least it would be better than polluting our way to global death....
Re:transport losses? (Score:1, Insightful)
Also the fact that USA is hostile to the rest of the world and extremely selfish, means no other country could trust it as a source of energy anyway. Example about the area was there just to illustrate, not as a concrete suggestion how energy needs of the world should be solved. There might be even better places in Sahara, but we'd still face the problems of moving the energy efficiently. Luckily, solar energy is quite easy to decentralize, however not suitable for every country.
Re:transport losses? (Score:2, Insightful)
Downsides (Score:2, Insightful)
Firstly, these solar cells are no doubt incredibly expensive - any high efficiency ones are. Secondly, they're probably made using rare and/or exotic materiels, making manufacturing in bulk tricky, and thirdly there's likely to be a lot of pollution created in the manufacturing process for by-products et cetera (it's a problem with less efficient cells too, but the more efficient ones are generally more pollutions).
Lastly, there's another issue. What happens when the sun goes behind a cloud? You need to be able to cover the entire slack in an instant, because you NEED a constant power output. That means you NEED enough GAS powerplants to power the whole world too, as they're the only type of power plant you can literally turn the dial and turn up the output.
Me, I'm going to be sitting here hoping that the test fusion plant they're building in France works, because from what I've learnt lately, if it doesn't, we're screwed.
Re:Cost is the issue (Score:5, Insightful)
Lots of animals and wildlife flora/fauna live in the deserts. Many of which are endangered. Many of which provide valuable eco-service to the land around them. It might not be prudent to just blot out the sun with solar collectors and think everything's going to be okay.
I'd rather see these on rooftops, supplementing power sources in a more local fashion where their impact will be minimal.
Re:Cost is the issue (Score:1, Insightful)
Re:transport losses? (Score:5, Insightful)
That statistic is simply an illustration in any case. Obviously there are some other places in the world where such installations could be put; perhaps some less sunny ones would require more space to reach equivalent capacity.
In any case, I think that a 100% solar earth is unlikely:
* Much of the time it is night, and storing that much juice in batteries is impractical. Things like hydroelectric storage and thermal solar plants could help with this problem, but its a whole different research issue.
* In the event of, say, a major volcanic eruption or meteor impact, world power production would plummet. That could be the least of our worries.
Solar and wind are like the icing on the clean power cake. They are great for the role they serve, but you can't have them for dinner without getting a stomach ache.
Still does not solve much (Score:4, Insightful)
Do not get me wrong. These solar cells are most likely a good thing. Of course, it depends on how the true cost relative to other methods. But this country needs to quit subsidizing oil and coal as well as have a multi-prong research in energy storage to really make the alternatives happen.
God, geeks are so incredibly stupid (Score:5, Insightful)
2. There is no reason at all to fill a desert with solar cells, and then transport the energy across to the other side of the planet. Solar cells are installed locally, like on your roof, or in your back yard, on every roof across the planet. Most of the electricity consumed would be as Direct Current right from your rooftop, with an inverter converting for those appliances you still insist on retaining that us AC.
3. For dense city sitatuions with high rises who's energy needs can not be met by rooftops, etc., electricity can be sent via conventional AC lines across the conventional power grid from say no more than 50 miles away. Not the other side of the world.
4. Those who produce an excess of electricity beyond their need, sell it into the grid.
Re:Downsides (Score:3, Insightful)
Presumably, you'd want the capacitance spread out across the grid- not only to prevent brownouts due to lack of power production, but also to temporarily handle spikes in load and to handle temporary grid failures. Neighbourhood or even house-scale capacitance units wouldn't require much storage and could effienctly handle temporary spikes in load, like the use of (for example) a microwave or vacuumn cleaner.
Of course, if you're splitting up capacitance that way, why not split up generation that way too? Just use the power grid as a way to ship excess power around to handle temporary generation losses.
Energy from the sun at maximum potential is what, 1 KW per square meter? My house's roof is probably 15-20 square meters; 12 KW on a sunny day is great. I have absolutely no idea at the moment how much power I'm actually using, on average, (including nights, etc) but I'll bet this won't be enough to cover it. That's okay. Even if it covers half of it...
Re:Still does not solve much (Score:3, Insightful)
Re:transport losses? (Score:3, Insightful)
While the major volcano/meteor event you mentioned could deplete the nuclear buffer, it would do that (and worse) now.
At the very least, considering the effects on the economy that nearly free energy would have, we could build enough nuclear power plants to completely handle our energy needs in case such an unfortunate turn of events occured. Hell, we could sell of the surplus nuclear energy to subsidize projects like the complete mechanization of food production, -- obviously using our nearly free energy. Or just lower taxes (though I would prefer the former)
Re:Cost is the issue (Score:4, Insightful)
In addition, as to farmland in the desert, well here is a couple of thoughts:
Re:transport losses? (Score:2, Insightful)
Re:Cost is the issue (Score:5, Insightful)
Looks like someone needs a refresher course in ecology. Deserts are very rich and diverse zones. Remember, a desert isn't just sand dunes. Just because it isn't green and not many people live there (the US West/Southwest) doesn't mean it's a barren wasteland. Also, the reason why the desert isn't farmland is because there is no water. The thing preventing Nevada from being a rich agricultural region is a rather large mountain range, not too much sun. Unless you can find a way of getting more water to the desert (like the Northwest) then it isn't going to produce squat.
Besides, other areas of the country still receive sunshine. I bet when you take into account the costs of maintaining the transmission infrastructure as well as the risks associated with a centralized power source most of the solar stations would be stationed near population centers instead of concentrated in one area.
Re:Cost is the issue (Score:4, Insightful)
I'm sorry, but this should never have been scored insightful. Its obvious at best, troll at worst.
First of all, improved efficiency reduces the investment cost, thus reducing the cost per watt (at least in a proper market economy, which the energy market unfortunately isnt).
Second, COx emissions are not the only environmental threat. In time, studies will more than likely show that covering vast areas of land with shadow-inducing plates (such as solar plants) has a negative impact on local and perhaps regional eco systems. More efficient solar panels mean less land area covered by solar plants, which is a Good Thing ®.
It never seizes to amaze me how people fail to look at the big picture;
* new cars emits less Cox and NOx, but the production of new cars is a significant ecological strain
* biofuel is great in small scale, but greatly reduces the ecological diversity and might pave way for invasive species
* solar plants might provide all the power the world needs one way, but at the cost of placing vast land areas in shadow
Etc.
The harsh reality is that there is no quick fix, there is no gratis lunch.
Re:transport losses? (Score:5, Insightful)
I agree that local micro power is another good peice of the puzzle. My number one goal in life is to eventually live in a home with a net energy surplus. Of course, my penchant for running Linux on old hardware might turn into a barrier to this.
While the major volcano/meteor event you mentioned could deplete the nuclear buffer, it would do that (and worse) now.
Well, given a 'minor' event like Mt. Saint Helens, light blocking would only be a minor concern to the overall energy supply as we have it now. Obviously ash and debris in equipment, supply chain interruption and so on would be another issue entirely.
Hell, we could sell of the surplus nuclear energy to subsidize projects like the complete mechanization of food production, -- obviously using our nearly free energy. Or just lower taxes (though I would prefer the former)
Well, that's a different question, one I hadn't considered too deeply. Still, until we develop a 'perfect' single energy source a la Mr. Fusion, there will have to be a wide variety of energy sources in order to have a stable energy system. Nuclear/fossil systems require finite and largely imported fuel. Wind, solar and geothermal require specific geography. Hydroelectric fsks up the ecosystem. Each has its place in the ideal system, however limited.
Re:where the facts? (Score:4, Insightful)
Re:transport losses? (Score:5, Insightful)
It's a lot more practical to scatter a large numer of smaller solar-plants around than it is to do the same with nuclear, oil or coal-powered plants.
If you do this, for example, by installing them on the roofs of homes you get 2 extra benefits:
Re:transport losses? (Score:5, Insightful)
At a large enough distance, all things are the same. Which removes distinctions which in real life are useful.
For example, the phrase "renewable energy-source" actually has meaning. True, one can claim that *no* energy-source is renewable -- because entropy will always increase, and for example solar-power is nuclear, and infact the sun is going to run out of fuel at some point.
Or you could argue the oposite; that pretty much all energy-sources are renewable; oil coal and gas come from organic matter afterall, so given a long enough time, there's no reason why they shouldn't renew.
But this is just playing word-games. You've told nobody anything new with this. We're talking here and now and on human timescales.
Oil won't renew -- in the next 10, 100 or 1000 years. So for practical purposes it's non-renewable.
The sun won't run out of hydrogen the next 10, 100 or 1000 years, and furthermore it doesn't run out any faster if we install solar-cells. So for all practical purposes, the sun is a constant source of energy.
Re:Cost is the issue (Score:3, Insightful)
Re:transport losses? (Score:3, Insightful)
How much is the total electric bill for the world?
Thermal is slow to start - but you can be prepared (Score:5, Insightful)
It takes quite a few hours to build up steam from a cold start and it wears everything out quickly by thermal fatigue if you have a lot of restarts. What does happen is something called spinning reserve where coal is being burned and the turbines are spinning but the generators are not connected. The generators can be attached by a very large clutch and more pulverised coal can be fed in to bring things up quickly - I'm too out of touch to know how quickly now and worked in new plants of an old design. With hydro you just turn on the tap and things happen quickly - thermal needs time (which includes oil and nuclear too for people who forget that nuclear is stream power).
Anyway - the troll way above was doing the "one true energy" thing which you only get from idiots or salesfolk. Just becuase photovoltaics are not a drop in replacement for every base load power source on earth does not make them useless. In remote areas they have proven themselves for decades.
PROGRESS WE BE SCREWED! (Score:3, Insightful)
And what about all the buggy whip makers!
Who is thinking of THEM!
Re:PROGRESS WE BE SCREWED! (Score:5, Insightful)
Yea, if only they could manage that! We could have a spirited argument on Slashdot article about it!
Well, when they're making them more efficent (sometime in the future, obviously), they could also work on making them indestructible as well! Like my windows.
Yes! Obviously they'll go bad, because everything has a short lifespan....ya know, like my house's foundation. It's only got 6 months left!
Ok, ok, enough of that. Seriously though. Did you read the SUMMARY? Did it even occur that maybe you should look up the lifespan of a solar panel before MAKING UP statistics? (40+ years, according to a cursory Google Search for "solar panel lifespan"
Please stop, its just painful.
Re:transport losses? (Score:3, Insightful)
Re:transport losses? (Score:5, Insightful)
Energy as we collect it now, has some non-obvious costs. What does pollution from burning fossil fuels cost us in terms of healthcare? What will sea-level rise cost us? (hint: NYC, LA, DC, Miami, New Orleans, Mobile, and others are very close to sea level, and those are just the US examples.) Would we really have spent $300B and 2,906 American lives (so far) in Iraq if we didn't need to "stabilize" the region that supplies most of our oil?
Part of every dollar that you pay in taxes, at the store, at the hospital, in fact pretty much everywhere, is an energy cost.
Re:transport losses? (Score:2, Insightful)
Re:transport losses? (Score:5, Insightful)
Also note that in your calculation you also have to add the savings in electricity. That is, you don't have to have equal price to conventional roofing, but you have to have the equal proce of conventional roofing plus the saved payment of electricity in some reasonable amount of time. So if the money saved on your electricity bill in, say, the next three years makes up for the extra cost of solar cell roofing, it's still more profitable to do it. (Well, actually you'll also have to account for the interest you would have gotten for the money during that time, because the money you pay for electricity next year will still give interest this year, while the money you spent on the solar panel will not.)
Hello terrorist target (Score:2, Insightful)
Of course you'd never want to put all of the collectors in one place...a few well placed munitions or a nuke from some rogue regime and there goes our power. Pretty effective way to incapacitate the nation, or throw the world into chaos if the power was being supplied throughout the world. Ever heard of offsite backup? Same principle. The collectors would have to be spread out in case of attack or natural disaster.
Re:Cost is the issue (Score:3, Insightful)
Plus I can't buy a residential wind turbine for $1/w. For a turbine (installed) in the 1-5kW range it costs about $3/w, with a big chunk of the cost being the tower & installation. $3/w is the same as the solar listed.
I haven't found a turbine for $2/watt until I hit the 20KW level. $40,000 is a lot to recoup and 20kW is a lot of residential power. I'll note that a 20KW turbine is only about about 2% more than 10kW turbine, so wind scales real well once you commit to spending $40,000+.
Which means that individuals will still find solar to be more appealing than wind because a) no tower, b) no moving parts, c) no moving parts located at the top of a 70' tower. Communities will likely find wind to be more appealing because a) it scales well, b) it requires fairly small land area, c) wind is generally more available, especially if you are willing to build a 100' tower.
So stop being a downer on solar, it's really like watching BSD & Linux fanatics going at it. If nothing else, the wind industry should be promoting solar to help get uniform nationwide grid-tie legislation passed.
Re:transport losses? (Score:3, Insightful)
Second, power reactors can remain hot at zero power for extended periods of time (called hot-zero-power or hot-standby). In PWR's, the reactor is designed to operate at a certain temperature (usually around 580 degrees F and 2250 psi). The reactor cannot be operated at colder then 540 degrees or so, due to physics limitations (moderator temperature coefficient, thermal stresses, etc). The way PWR's initially heat up the coolant at the beginning of a cycle is by simply running the coolant pumps. The pumps that circulate the coolant are monstrous (~7000 hp) and can heat up the system to operating temperatures all by themselves. They also keep the water at hot conditions while the reactor is at zero power.
In a world powered entirely by solar panels, large nuclear power plants for use at night or in case of volcano would work just fine. This is because if they were needed, they would be operating at 100% as base load plants.
Re:transport losses? (Score:3, Insightful)
NO, get rid of that power robbing, terroist target, lightning rod, ice gathering, bird killing, people killing, expensive ass eye sore.
I don't know how many billions of dollars our federal government spends on that grid every year, but anything to minimilize thing would be sweet, even if it takes more energy to produce a solar panel than it ever produced (fairly certain it doesn't.) I still think it would be worth putting solar panels on every roof just to have a single delivery charge, and not a constant drain.
I do think having developments linked is still a good idea, but if the load can be minimized, then the losses, maintaince, EMI emissions will drop to nothing as well. In Tuson now we have self sufficient communities running from solar, and a central connection for load balancing (I assume a central generator/connection to grid is present as well.) So you can supply the surge loads if a AC, and refridge kick on while running the microwave, and TV. That would be covered by your neighbors solar who are out of town/at work, and yours would do the same for them when your out.
Re:transport losses? (Score:3, Insightful)
Think in-city clustered 12 story apt buildings. A simple building, 1 apt per floor, say a 1000 sq ft apt. So we have 12 'stacked houses' that have a single 'shared' 1000 sq ft roof. So 1000 sq ft of roof needs to support 12 'houses' of energy. Unlikely. THAT'S why the grid comes in. In clustered/dense city dwelling environments, roof top energy generation will be insufficient to cover the usage. We'll always need a 'grid' in that environment. How we fuel/supply the grid may be debatable but the existance is required due to the space/environmental constraints.
Re:Grandpa was a Buggy Whip Salesmen (Score:5, Insightful)
Circumstance dealt him a series of "losing" hands, but he didn't bitch and moan and expect someone else to "make it right". He worked, very hard I'm betting, and became wealthy.
Based on what's I've read in that other discussion, he must have been a very wicked and greedy man.
I salute him.
Re:transport losses? (Score:1, Insightful)
Energy as we collect it now, has some non-obvious costs. What does pollution from burning fossil fuels cost us in terms of healthcare? What will sea-level rise cost us? (hint: NYC, LA, DC, Miami, New Orleans, Mobile, and others are very close to sea level, and those are just the US examples.) Would we really have spent $300B and 2,906 American lives (so far) in Iraq if we didn't need to "stabilize" the region that supplies most of our oil? Part of every dollar that you pay in taxes, at the store, at the hospital, in fact pretty much everywhere, is an energy cost.
Wow, nice answer and totally uncalled for. If you really want to see solar displace oil, somebody needs to start selling solar cells that match the cost per watt of oil. There are two ways for that to happen. The first is for the supply of oil to shink (in progress) and drive the price of oil up, and the second is decrease the cost per watt of solar. More efficiency for the same price is a good example as is a decrease in the price of solar.
Everything else cited? It will still be there. Solar is not zero pollution. It just shifts the type and source and spreads it around. Much like coal vs hydro. Do you have any idea what the thermal runnoff is from solar? You want to talk about global warming and healthcare problems? Look no further than the next great energy source. Wars have been fought over far less than potential threats to energy sources. Many more wars will be fought over much less than that as well.
The goal is greater efficiency and sustainability. It is the same reason why farming beats hunting. Right now we are "hunting" energy sources, not "farming" them. That is starting to change, but it needs time (and technology). Just as farming didn't happen overnight, nor will our energy shift. Do what you can to help make it faster, better, or cheaper and it will be here before you know it.