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Solar Power Becoming More Affordable
prostoalex writes "With both startups and large companies such as Boeing working on solar power, the technology is becoming more affordable, MIT Technology Review says. Solar power concentrators are all in rage now: 'The thinking behind concentrated solar power is simple. Because energy from the sun, although abundant, is diffuse, generating one gigawatt of power (the size of a typical utility-scale plant) using traditional photovoltaics requires a four-square-mile area of silicon, says Jerry Olson, a research scientist at the National Renewable Energy Laboratory, in Golden, CO. A concentrator system, he says, would replace most of the silicon with plastic or glass lenses or metal reflectors, requiring only as much semiconductor material as it would take to cover an area the size of a typical backyard. And because decreasing the amount of semiconductor needed makes it affordable to use much more efficient types of solar cells, the total footprint of the plant, including the reflectors or lenses, would be only two to two-and-a-half square miles.'"
This headline can be recycled and reused into perpetuity. Chances are with continuing advancements it will always become more affordable than it was last week, month, year, decade, or century.
But when will it become truly affordable for the masses? That's what most of us want to know. Wake me when it's time to disconnect from the petroleum/nuclear fired grid.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
Why all the talk of centralized power generation?
:p) energy would a fraction of what it is now.
Solar panels are the way to put power generation into the hands of the people. When I look out at all the rooftops in the area - houses, office buildings, Super S-Marts and their enormous un-covered parking lots, all I can think of is if every one of those surfaces had a single solar panel our energy demands from centralized (corporate
Have we learned nothing from decentralized computing?
years. One of the major problems of concentrated solar power is the heat - normal photovoltaics would melt. The benefit is that concentrated light also has better efficiency than the normal ~10-22% of normal solar power. One of the traditional ways around the heat problem wasn't to use a photovoltacic as all. An energy farm in Australia uses dishes to focus the light and at the focal point places a stirling engine, with only the heat powering it. Interesting stuff. I hope to have my own workable solar power system power my property one of these days.
Let's see, four square miles of sunlight focused onto my back yard. Conversion efficiency ~30%. Melting point of silicon 1414 deg C.
Unless I've got a backyard the size of Bill Gates, lifetime of new solar plant = one sunrise.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
That's an interesting comment because the price you quoted is roughly the cost of building a new 1 gigawatt nuclear power plant. How do you think the costs of nuclear qualified workers, nuclear fuel, insurance, long-term storage of spent fuel all compare with the labor costs of cleaning plastic mirrors once a year?
Americans vote Democrats control of our government, and suddenly 3 days later solar power could be affordable. When they actually take power on 1/3/2007, will we finally get our goddamn flying cars?
--
make install -not war
What about in summer? The windows can be opened and replaced by screens or shaded.
-b.
They are, only problem is that you can't know both what their position is on an issue, and how fast they want to implement it.
Also, I think they have a dead cat, or something....
Is this at all related to what Energy Innovations has been doing?
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Then again, they could just reorganize and move into the manufacturing and maintenance side of things. Someone will have to fix and maintain the solar homepower systems ultimately. The one major advantage of having a power distribution grid, though, is the ability to redistribute power. If Sunville, AZ is having a month of sun with no clouds, and it has been cloudy for a month in Bad Ass, MS, the energy can be redistributed so that all of the Badassian's batteries don't run down.
-b.
One thing I really wish would happen is that the efficiency of thermovoltaic technology could somehow be improved... Think about how much energy is wasted as heat; eventually all of it, I suppose. I actually heat my bedroom in the winter with my PC. When I read about large scale solar facilities, I can't help but wonder at the losses in heat that are going on there. There are more efficient ways of utilizing solar power right now anyway: http://www.stirlingenergy.com/ comes to mind... and they work pretty well. It would be nice, however, to move the technology to solid state like we have with photovoltaic cells; That way we could apply them to things like brake shoes on cars, the condensers on refrigerators and air conditioners, etc... -Photovoltaic paint has been invented, but is not realistic yet. I think that's where the future is: Objects that need electricity should become more efficient, and should have photo/thermovoltaic technology built right into them.
-ubuntu others as you would have others ubuntu you.
Just think ... to save even more space, we can use several layers of reflectors ... oh, wait ....
Take hydrogen. The day someone figures out how to easily produce hydrogen the days of energy monopolies are over - anyone with access to water
Ok, one last time hydrogen is a carrier of energy not a generator. H20 -> H2 into whatever storage device -> H20(exhaust frm fuel cell) not really going to gain a ton of energy. Sure it's relatively clean(although you are turning a bunch of liq H2O into water vapor) but hydrogen has energy density problems that need to be solved. So basically, stop getting your science info from Keanu Reeves movies.
I laughed at the weak who considered themselves good because they lacked claws.
Part of the problem is the durability of these panels. The affordable ones have relatively short lifespans (under 10 years, and at that point, still haven't saved enough to justify their cost). The ones that ARE durable enough to last longer are hideously expensive, and not the sort of thing most people have the cash for.
Also, there's the fact that solar power is not a viable solution everywhere in the world. Sure, in Arizona, California, etc, it is a wonderful "free energy" thing.
In Pacific Northwest, the northern Midwest, etc, especially during the winter months, solar power is a complete non-option.
Chas - The one, the only.
THANK GOD!!!
Let's just say that it costs a super cheap 20$ a square foot. The cost of the mirrors alone would be $1,115,136,000.
Wow. I can make up numbers too. Let's assume it was a "super cheap" $2 a square foot. That's only
$115 million. Oh wait, let's assume it's only
Rather than pulling numbers out of your ass, maybe you should have real estimates of what it costs to make a plastic mirror. Considering you can make wood flooring for
AccountKiller
you seem to be a little uncertain about your position on this... how fast are you traveling?
Donald 'Duck' Dunn: We had a band powerful enough to turn goat piss into gasoline.
The problem with all these "The Big Bad Industry doesn't want X to succeed!" is the absolutely staggering number of X's that have nonetheless succeeded. Who cares what my power company "wants"? If I could buy cost-effective solar, I would. I can't. (And given that I live in cloudy Michigan it's going to be even longer for me than for some of you, but that's just a detail.)
Good luck to any power company foolish enough to stand in the way of something with the PR power of solar power. Can you imagine the media bloodbath that would ensue if any power company executive even mumbled something about getting solar outlawed?
Seriously, less emotion, more brain. It's the Universe making solar power hard, not a conspiracy of apparently-omnipotent "evil executives".
But the demand for silicon in the creation of computers, has kept the price high. It is an ironic, catch 22 situation.
But there is hope. If we ever switch to non-silicon based computers, the price of pure silicon is expected to drop to a level low enough to make cheap solar panels a reality.
excitingthingstodo.blogspot.com
Actually, a heat pump is a bad example, since you're putting energy in to move heat, not moving heat and getting energy out. With an engine, the amount of heat moved always has to be greater than energy out. Same with a heat pump - you actually can move more heat energy than you put power in. Hence coefficients of performance greater than 1.
-b.
Your model (a heat engine) doesn't really work for solar cells, although you are certainly correct that 100% efficiencies are unobtainable.u ll-spectrum-solar-cell.html
In solar cells, the point is that photons excite valence electrons across a barrier, giving them enough energy to create a current. There isn't really a classical analogy for this effect.
There's a limited discussion of solar cell efficiencies here, although it doesn't talk much about the underlying physics:
http://www.lbl.gov/Science-Articles/Archive/MSD-f
The upshot is, cells of a single type of material can only get up to about 30% efficiency, but we can stick several materials together to get past that barrier.
I know that in the roofing industry you can put down a membrane that complies with CRRC requirements and within a month it won't. Granted, we're talking about relatively flat horizontal surfaces but anything left outside almost immediately begins losing measurable reflectivity from dust and dirt.
"Sacrifice for the good of The State" - The State
I've worked a lot with photovoltaics. They're really cool, but I recognize their limitations for utility-scale power generation. The primary limitation is that silicon-based photovoltaics currently convert only 10-23% or so of the incident solar power into useful electricity. Silicon solar cells cannot convert infrared light to electricity - the photons have too little energy. Higher energy photons (visible and UV light) are poorly utilized - a solar cell will get the same energy output from a red photon as a blue one, despite the fact that the blue photon has higher energy. Solar cells aren't very reflective (by design), so most of the remainder of the unconverted sunlight becomes heat in the cell.
You can get higher efficiencies by going to other chemistries, like GaAs, and by layering different chemistries on top of one another. These are not cost effective, and won't ever be able to get above, say, 50% efficiency.
But solar energy is not limited solely to photovoltaics. Probably the best way to use solar energy is solar thermal - capture all that 1000 W/m^2 of incident sunlight as heat. It can be used to heat a fluid up to fantastic temperatures, which can drive turbines, etc. This is the principle behind Solar One, Two, and Tres and the Nevada Solar One plants. These are, however, demonstration plants, not utility scale.
The other major kind of solar energy is biomass. Photosynthesis is a pretty good way to capture sunlight and make it do something useful. Plants have had a looong time to get good at making use of sunlight, which we use to our benefit in many ways. When cellulosic ethanol comes around, you'll probably make better use of sunlight by planting crops and building a solar power station.
The cost of the mirrors alone would be $1,115,136,000.
Ok I'm going to add around another billion to pay for cleaning equipment, staff, etc.
Let me pull some numbers out of my butt.
I'm also not a physicist so forgive me if I've made a basic mistake in my following assumption: For your $2B investment you get 1 gigawatt production. What is this - 1 watt = 1 Joule per second, if I remember. So 1 GW = per second. After 3600 seconds you are getting 1GW/hour. Dunno how much a KW/hr costs in your locale, but here it's about $0.12. 1 GW/hr = 1 M Kw/hrs = 1M x $0.12 = $120k worth of energy produced per sunshine hour. Does it pay the interest on the investment? Say you had 2 hours decent sunshine a day on average (because some days it will be cloudy and you won't get 100%) = $240k a day. That's about $87M a year. Hmm, dunno if it's worth it, actually, once you take out operating costs, depreciation, etc. For now. But it could be, someday, if the price of energy goes up much higher. It's not _that_ far off.
Seven puppies were harmed during the making of this post.
I searched on 'mirror cost "four square feet" solar' and the Google summary for the second hit showed a cost of $5/sq. foot. That's an upper bound, as I'm sure economy of scale would kick in. So, for 2.5 square miles or 70 million square feet, that's about $350 million dollars. As others have said, not bad for a 1GW power plant.
Ben Hocking
Need a professional organizer?
We still need better inverters. These are the devices that convert DC into AC for use by common appliances and to power your home. The ones designed for home operation are wimpy, apparently intended for a home where people trim back on using energy in electrical form, already. The ones designed specifically for the wide range of voltage change from photovoltaic arrays/strings are big expensive commercial units intended for selling power to utilities, or for the utilities to buy for themselves (they shut down and night and can't run from batteries very well).
I want to reduce my carbon footprint with emphasis on reducing use of fossil fuels in particular. I'm less concerned about burning wood than I am about burning gas (natural gas or liquified propane). So I'd like to run my kitchen from solar and wind generated electricity. That means I need on the order of 12 kW of power just for potential peak cooking. Add another 2 kW for microwave. Add some more watts for the blender, coffee maker, refrigerator, etc. It adds up.
One of the big makers of home inverters for general DC conversion (e.g. batteries charged from various sources) is Xantrex. But their largest unit in this market segment is only 5500 watts. Two of the North American 120 volt units can be "stacked" to get 120/240 volts, but that's still only 11 kW. Some other companies offer as much as 6000 watts in a single unit, and do not even appear to be "stackable". What we need is a line of inverters, each specifically designed for the various world power systems so people can use their common domestic appliances, but with a variety of power levels in many steps all the way up to 100 kW or more.
There is one technical issue with inverters, and this is not something that is easy to solve. It also exists to some extent with small generators. That issue is that under short circuit conditions, they produce only barely (about 15%) more current than their design rating. To many this might seem like a good thing. But it actually is a hazard. The reason is because short circuits will fail to trip home branch circuit breakers. A common circuit breaker rated for say 15 amps generally won't trip for a while under a 20 amp load, until its thermal element gets quite warm. For an instantaneous trip using its magnetic element, the current has to be significantly higher, like 150 amps or more. Utility power through a transformer can easily deliver several hundred amps under a short circuit condition. With hefty power lines and transformers these days, if you are close to the transformer, you could even get several thousand amps real close to the breaker panel. This is why if you have ever shorted out a power circuit, you get a nasty *POP*. That's some big amps followed by the breaker cutting the circuit off.
I've found some inverters that have circuit breakers on the output AC side that are rated at a higher amperage than the maximum they could deliver under a short circuit condition. In other words, short out the AC right after the circuit breaker and you can't even get enough juice to cause the breaker to kick off. The inverter itself may very well detect the overload and soon shut off.
Many appliances may not even work under this low fault current condition. Big motors can have trouble getting started if they can't pull 3 to 5 times the normal amperage for part or all of a second. And even some electronics wants that much power or more when you turn them on to charge up the power supply capacitors. One relative has found that his big screen TV, although using way less than the 5000 watts his generator can produce, just won't even turn on under the generator. When he turns it on with utility power, all the lights in the house dim significantly for just an instant as the monster sucks a huge number of amps.
Ultimately, if you want to power you whole home with AC power through an inverter that converts the DC stored in your batteries charged up from your solar and/or wind power sources, you'll need some hefty
now we need to go OSS in diesel cars
Finally - this can only mean that Halliburton and Bechtel decided to lower the price of photons!
"Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
There has to be a HUGE stockpile of old AOL CDs still out there, lets put them to good use.
These concentrating lenses do not need to be very complex at all. In fact they don't even need spherical curvature at all. What they need are angles. That effectively makes a crude, but adequate, Fresnel lens. With flat surfaces, they are also cheaper to make.
The original Fresnel lens design for lighthouses needed to work with a very small focal point, the light source, and beam that light very straight. Thus it needed that spherical curvature. Even in its varies steps or layers, that sperical curvature still exists. Solar cells, however, do not need this.
Suppose you have a small solar cell module that measures 10cm x 10cm. Place it at the center of the back of a larger 50cm x 50cm box with the front aimed directly at the sun. Over the front of the box place a 5x5 grid of 25 openings, each the size of the solar cell. In the center, only a flat piece of plastic is needed. Outward from the center, a piece of plastic that is angled like a thin prism would be placed to bend the light at the necessary angle to hit the solar cell at the back. You'll have to figure out the right angle based on how deep the box is. But you will only need to have just a few different kinds of angles to complete the construction and concentrate almost 25 times the light onto the solar cell. Solar cells even operate more efficiently on concentrated light levels.
The box will need to track the sun to keep the various angled beams focused on the solar cell.
An alternative design is a box that is wider in one dimension and has open sides in the other. Stack multiple boxes with the wider dimension vertical so their open sides mate with each other. Tilt the stack to the angle of the sun's path and aim it for about the noon sun position. Then the morning and afternoon sun will be at an angle that lens light from one of these narrow boxes go through the mated openings and hit the solar cells of the adjacent box. You only lose what would be at the ends but you don't have to set up a steering mechanism.
Variations of these designs use mirrors instead of lenses to concentrate light. I personally favor the mirror designs using non-imaging reflective topologies. The same methods are also used for water heating.
Also consider using a water heat collector behind the solar cells. They do get hot (they aren't 100% efficient, so the energy is wasted somewhere).
now we need to go OSS in diesel cars
I'm sick and tired of you naysayers and skeptics bringing up conservation laws. Didn't the conservatives just get thrown out of congress? Now those pesky conservation laws can get repealed once and for all!
And maybe they'll do the laws of Thermodynamics while they are at it.
You forget the five Solar Thermal plants at Kramer Junction which together produce 165 MW. SEGS III - VII, as they are called, have been in commercial operation for around twenty years now. These are definitely utility scale plants, not demonstration plants.
Um.... thats ALWAYS what you are doing.
I once heard a mechanic say "You can just think of an engine as a glorified air pump" (a really dirty one)
The point is you just have to change how your looking at it. To see a heat pump as a generator, look at hot air on one side as fuel being burned (with colder air being the exhaust output) and hot air on the other side as the output energy.
Actually it has 2 fuels... the electricity comming in too. So it burns electricity and hot air, and makes hot air on the other side.
An air conditioner is just a heat pump where you hang out inside the "spent fuel tank". Its kind of like an engine with no alternator so it needs an external power source to spark the gas. And instead of hooking up a cam shaft, transmissions and wheels, you just pump the exhaust into the room to keep warm (finding the problems with that plan is left as an exercise to the reader)
-Steve
"I opened my eyes, and everything went dark again"
Energy Innovations has tried Fresnel and is working on mechanically steered 5x5 set of mirrors.
Your box sounds promising but a grid of them requires an elaborate supporting frame? The Energy Innovations Sunflower 250 lies flat on the roof. Your water heat collector adds expense.
=S
Aren't they the party that proposes setting national policy by a daily horoscope? That would make the United States a Cancer...
(Stop that snickering, you in the back!)
Strike while the irony is hot! -- The Freethinker
What? You've never heard of the were-car?
Live forever, or die trying.
The problem with solar power is never the efficiency of the collection system but rather with the fact that the power cannot used on demand. Without a staggeringly efficient means of storing the power, solar power will remain useless for all serious generation. There isn't a single factory, communication system, transportation system or any other important part of our civilization that runs off solar power and baring currently unforeseen breakthroughs in storage technology there never will be. We simply can't run a modern civilization off a power source that randomly disappears. Every solar power installation requires a 100% non-solar redundant system to take up the slack when the solar goes off line. Factor that cost in and solar power becomes an economic joke.
Solar power isn't a solution. Its a distraction. It lets politicians and others pretend that they are doing something about serious energy questions instead of making unpopular, real-world choices.
They already do it in Missouri. Check out the Taum Sauk pumped storage plant. Pump the water up the hill during the night when there's excess power and dump it back through some turbines during the day when you need it.
The best thing about solar, though, is that peak demand is in the middle of the day...when solar is generating the most it can. So you just flip the system around. Use storage methods like on Taum Sauk to stockpile nighttime power to pick up the solar shortfall then.
>That's not going to happen. The most plentiful source of hydrogen on the planet is water.
>No one is going to be able to figure out a system that uses less engerdy to split the molecules
>than you get in return by burning the hydrogen or using it in fuel cells.
Man, there are a shit-load of things we buy and use every day that consumed more energy in their making than I get out of it in the end product.
My reply to this is a big fat "so what"!
Let's say it takes 100 times as much energy to make a volume of hydrogen than I get when I burn it in my car (I'm pulling this number out of my ass).
If the hydrogen is cheap, compared to, say, gasoline, who cares how efficient it is?
OK, so we need a nuclear reactor or giant solar concentrators to crack the water into hydrogen and oxygen. As long as the economies of scale make the end product (they hydrogen) cheap, I don't really care how inefficient the process is to produce it.
The trick is to find a cost-effective, hopefully renewable way to produce hydrogen. Efficiency is secondary.
A work that expires before its copyright never enters the public domain and thus enjoys eternal copyright protection.
Take hydrogen. The day someone figures out how to easily produce hydrogen the days of energy monopolies are over - anyone with access to water (or whatever the raw material turns out to be) can do it.
Making hydrogen isn't the problem. Storing it, transporting it, and keeping it from leaking out of every valve, seam, and fitting along the way, are the problems.
Downmodding is the refuge of the weak. Don't downmod, make a better argument!