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World's Largest Solar Array to use Stirling Engine
An anonymous reader writes "Stirling engines are not a neglected or forgotten technology after all, according to a story at PESN. With 20 years of in-the-field fine-tuning, Stirling Energy Systems is now ready to go big -- real big. They signed a purchase agreement Tuesday with Southern California Edison (SEC), to install a 20,000 dish array that will cover 4,500 acres and will be capable of generating 500 megawatts of electricity -- more than all other U.S. solar projects combined -- making this the largest solar installation in the world. Each collector has a 37-foot-diameter array of mirrors to focus the sun's rays on the Stirling engine, which turns the heat into rotational torque for electricity generation. According to a spokesperson for SCE, this purchase will be in their commercial interest, requiring no subsidy in order to compete, implying that the efficiencies of the technology will give them an edge in the market."
If anyone is wondering, 500 megawatts can power about 500,000 homes.
Sterling engines are pretty cool. They have one huge advantage over silicon solar power: much much less pollution in production. Photovoltaics are basically large chips, they use the same nasty chemicals and lots of electricity. Sterling engines are just machines, and very scalable apparently.
Funny that one solar-dynamic powerplant will double the solar power being utilized.
One of the Sterling engine makers has a deep-space powercell that combines a sterling converter and a big hunk of plutonium oxide. Man, I wish I could get one for the basement...
Josh
gigantino.tv - Heavy but weighs nothing.
The voters here in Colorado were suckered into an initiative requiring the utility companies to get 15% of their power from renewable sources whether it made economic sense or not. Since it looks like this thing actually does then I hope someone from the local utility reads /.
This is taking place in California...
Signed Tuesday, the 20-year power purchase agreement, which is subject to California Public Utilities Commission approval, calls for development of a 500-megawatt (MW) solar project 70 miles northeast of Los Angeles using innovative Stirling dish technology. The agreement includes an option to expand the project to 850 MW. Initially, Stirling would build a one-MW test facility using 40 of the company's 37-foot-diameter dish assemblies. Subsequently, a 20,000-dish array would be constructed near Victorville, Calif., during a four-year period.
It sounds a lot smaller when you put it that way.
The Edison URL should be www.edisonnews.com. Yes, we require you to put the www on the front of it. And yes, I work for them.
Fantasy remains a human right; we make in our measure and in our derivative mode... -- JRR Tolkien
Stirling engines certainly aren't forgotten or neglected. Swedish submarines use Stirling engines for propulsion, for instance.
Trust the Computer. The Computer is your friend.
Stirling engines seem legitimate enough, but the linked site describing them seems somewhat crack-potish. They promote cold fusion and zero point energy, as well as a number of "alternative energy sources" I've never even heard of. There's also a page trying to disprove the Peak Oil theory, which should be real popular with the Slashdot crowd. Anyway, I sometimes wish that /. nerds had a greater understanding of the pure sciences, rather than just software engineering. Oh well.
Let see, it is about $5/gallon in the UK and the US is complaining about $3/gallon wtf. This is just under estimate too because I am converting from £ to $ and liters to gallons.
http://en.wikipedia.org/wiki/Stirling_engine#Probl ems_with_Stirling_engines
Quantum mechanics: the dreams that stuff is made of.
Yeah, parabolic dishes just don't seem to come naturally. (This particular one is made from mirrors with ?5? different circular curvatures arranged parabolically, if recall correctly) Some groups have made test dishes by applying a vacuum to the backside of a thin stainless steel sheet and heating it, then keeping it under a slight vacuum. This doesn't produce a perfect parabola, but it's better than circular, apparently. Some examples are here: http://www.psa.es/webeng/areas/instalaciones/disco s.html
There have already been two big solar projects in Southern California Edison territory, called Solar One and Solar Two. Both were so expensive to operate that they couldn't even cover their operating costs, let alone their construction costs.
Yeah. Because everyone wants a nuclear reactor that combines the wonderful properties of graphite (see "The graphite fire" subsection) as a moderator, with water (graphite generates explosive hydrogen with high temperature steam) often in the primary or secondary cooling loop (helium is the primary coolant), with safety features such as no containment structure (this list is just a start - there's many times more that didn't make the list)
Yes, PBMRs have a negative void coefficient (reaction slows as temperature increases); big deal, so does almost every reactor build in the west in the past three decades. Yes, helium is the primary coolant; that doesn't help when there's a jam or corrosion that leads to a rupture, in which case water and/or air enters the chamber (a much hotter chamber than PWRs) - and yes, this has already happened. Containment structures have saved our collective arses from the unexpected too many times to be omitted.
PBMR proponents talk about safety, but they're really about reactor cost. They're hardly the only innovative reactor design out there, but they're apparently the only one that your average slashdotter knows about. There are thorium breeders, reactors that run on unenriched fuel, and designs like my favorite, BREST - a lead-bismuth breeder which can cool itself with natural convection, uses the ground as shielding, has the fuel naturally encased in lead, and unlike most breeders, uses no liquid sodium.
As an aside, we really should move to safe breeder designs, either thorium or uranium based.
U-235 is only 0.7% of natural uranium, and natural uranium isn't incredibly plentiful in deposits concentrated enough to justify mining (I read once that known deposits would supply the world at current power consumption for only a few hundred years). It's a shame that most U-238 goes to waste (yes, some is used in things like armor, bullets, and weights, but we produce far more of it than is used for such tasks)
Next to my desk we have an Ire Extinguisher. Our boss is really assertive, so we like the idea of having it.
...Yes, we require you to put the www on the front of it...
Then you have a brokeass CNAME entry which goes against the RFC's, if I recall.
Do the internet a favor and just say no to worthless CNAME crap. A browser will get to the right place without that dumbass "www" tacked to the front of a domain name.
The problem with radioactive waste storage is not the shielding, it's how to prevent groundwater over hundreds or thousands of years from getting into the storage facility and dissolving/carrying off radioactive material into the water table. This is the big concern holding back the real planned waste storage facility, which is in a deep, dry hole in the middle of nowhere. They need to prove first that whatever they put there will stay put for tens or hundreds of thousands of years.
I'm not sure why the lack of interest in pebble beds, but I'm guessing they need some political pressure...
As I understand it, the pebble bed nuclear reactors make it really hard to re-enrich the uranium after usage. This is a bad idea as re-enriched uranium can be reused and produces less radioactive waste in the long run. All we have to do to solve the reenrichment problem and a large part of our nuclear waste is to build a fast breeder reactor and start recycling the used material.
This was the original plan when nuclear power plants were first developed. President Carter used execuitive order to ban fast breeder reactors back in the 70's, so it wouldn't take much to undo that ban.
Fly me to the moon Let me sing among those stars Let me see what spring is like On jupiter and mars
Because, naturally, you know more about the economics, safety, and other issues relating to various nuclear reactor designs than Southern Company.
Do you even know *any* next-gen reactor designs besides PBMRs?
Next to my desk we have an Ire Extinguisher. Our boss is really assertive, so we like the idea of having it.
Oh! Logic train a'comin!
:P
ding ding ding Ding Ding DING DING DING Diing diiing diiiing.....
Darn, missed it.
Plain and simple, gas prices in Europe are high because of taxes.
Oil companies aren't monopolies - it's a very varied industry, and fiercely competitive. It's worse than many industries, because they're all selling essentially the same thing. They'll push particular blends and additives, but it really comes down to the same product, so it's really down to whoever can sell it the cheapest.
By the way, the main reason that oil companies are turning such tidy profits right now is because they had been working to be profitable at 20$/barrel, and suddenly it's at 60$/barrel. Note that the high prices are much more of a benefit to producers than refiners, although the whole industry is quite profitable right now. If you have infrastructure or build infrastructure, it's in such demand, you're going to make money.
Next to my desk we have an Ire Extinguisher. Our boss is really assertive, so we like the idea of having it.
Car engines can't be nuclear. While nuclear reactors can be made with the appropriate power output for a car, the biggest problem is that the driver would be killed by the neutrons that would drift out of the engine. Neutrons are a bitch to shield against and a car would not be able to carry the necessary material.
Just spit balling but couldn't fresnel lense technology (Giant Fresnel Lense) be used to increase efficieny, or reduce the size of the dish. Then use fly wheel technology to store excess energy for night time use.
The fresnel lens could reduce the surface area of the mirrors, but not of the over all area. The amount of light energy from 1 acre is the same whether you condense it using a lense or a mirror. In addition, with the extra complexity and cost of the lens, you might as well just stick with a mirror (plus the lenses are probably more fragile).
As for the fly wheels. Think about how big and how many flywheels you would need in order to store 3gigawatt hours. That is 250Mwatts for 12 hours. Plus inefficiencies in the bearings and conversion of the power would reduce the stored energy.
Fly me to the moon Let me sing among those stars Let me see what spring is like On jupiter and mars
A company in Australia is developing this type of technology for self-contained power generation in remote locations (and 3rd world countries/natural disaster areas). They are using a parabolic dish made from mirror polished bands of stainless steel. Stainless steel (while expensive) stands up to bad weather much better than glass mirrors - and by making the dish with bands (with gaps in between them) you reduce the effect that wind had on the dish.
They are making a dish that isn't affected by wind (except for wind that flattens buildings) doesn't get damaged by hail (unless it's bigger than a cricket ball) and is only 5% less efficient than the same size mirror dish. They don't have a website worth mentioning - but they are developing all this in conjunction with the CSIRO - so you may find something here (CSIRO) http://www.csiro.gov.au/ about it all. Look for Sterling engine power generation. The CSIRO did publish something recently in a subscription only publication about this.
In case you were wondering how I know - my brother works for the small electronics firm that came up with the parabolic dish idea. They have also come up with a sun tracking mechanism that costs $15 to manufacture.
Pity a 5KW generation system costs $25000 all up - but they expect it to last for 25 years or more.
All dollar figures here are Australian Pesos.
Oh yeah - they get around the "How do you generate electricity at night without sunlight light" issue, by using the dish to heat up 300KG (or so) of salt and graphite - which then acts as a heat battery. Apparently they can run the Stirling engine for 3 days or so after the Salt Cell gets to about 900 degrees centigrade.
Drawbacks? Here's some, although they are neither (IMHO) all that serious, and I like this technology as a whole, and would say these won't stop it in the long run.
1. Heat - Focused mirrors in large banks are extremely hot at the focal points. When you're talking 500 Mw. output, your talking about lots of points inside that 4700 acre area where temperatures must be enormous (3,000 degrees F or so if the focus is at all tight).
Basically, anything that involves a huge energy differential has some potential for that energy to go in directions we don't want. The potential may be lower for some technologies than others, and this may well be one of the good ones, but by the very definition of energy (the ability to do work), there is no energy technology that can't do some work we don't want, whether it's a dam breaking and all that water working hard to wash away a town downstream, or mirrors getting focused on the wrong points, and the wrong things getting hot (like employees on site, or the supports and braces for other mirrors).
2. Not only can you not produce power at night, but cloudy days reduce your efficiency. Power draw on the grid is (usually) only less at night in the summer, when a lot of electricity is going to air conditioning. In winter, power draw is more for heating and people heat most on cold nights. Days are also shorter, plus sunlight is passing at shallower angles through the air and so has less energy per square foot, so even if this system is very, very efficient at the best of times, it becomes just half (or so) of a two part solution. At best, it's likely somewhat more than half, and maybe cuts fuel oil and coal use by a very nice 60-70%, but it simply can't do away with them entirely.
Now for the bad news - A power company that only needs 30% of the fuel oil it did won't see a full 70% savings - the way their contracts work, they will probably only see about a 50% savings on oil costs, so that financial 'damping' effect slows adoption of technologies like this. They have to prove themselves to conservative investors, and even then they have to offer big improvements and not just small ones, or they take 20 years or more to catch on.
This is a catch 22. If the technology caught on really fast, then basic macroeconomics holds fuel oil prices wouldn't continue to rise, because demand would decline. But since the technology simply can't catch on all that fast, places that haven't adopted it yet will continue to drive demand higher, the early adopters will get smaller discounts because they are buying only seasonally or in less bulk, and the rate of adoption will be slowed further.
Who is John Cabal?
A nuclear power plant will produce on average 80-85% capacity with 90%+ uptime. Uptime for solar will be at most 50% as you only have sunlight for 10-12 hours. Then, will it be producing 100% capacity for those 10-12 hours? No.
Well too bad for you. Meanwhile cars like the original VW Beatle have about 30 horespower (at the wheels), and don't have trouble climbing hills. Your VW might have 95HP PEAK, but at the wheels, especially while climbing, I bet you're getting a fraction of that. Electric cars don't need transmissions, and other horsepower-sapping equipment that ICEs need.
But that's really irrelevant, anyhow. The parent didn't even suggest that solar panels would be the sole source of fuel for future vehicles. If you've got an electric car, put a solar panel on the roof/hood/trunk, and you get more range. You'll save money from not having to plug-in as often. Horror movies will run out of plots, as people that run out of fuel in the middle of nowhere need only wait in their cars for an hour, (while it recharges itself) before continuing to drive. And people that use their vehicles for short, infrequent trips might never need to plug their vehicles in.
Note that "short" means distance, not time. Without the need to keep your engine running, you can sit in traffic for hours and use almost no power.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
Since I'm probably not the only one that don't know my reactors that well: http://www.nrc.gov/reading-rm/doc-collections/fact -sheets/next-gen-reactors.html :p
www.aleo.no
1. There is a big debate over the graphite's role in Chernobyl. The Soviets who put out the fire were insistant that the graphite was burning - they even had debates over how to put out the burning graphite without encouraging faster burning or secondary reactions. Nuclear professionals in America are insistant that nuclear grade graphite only erodes - that it doesn't burn - and lab tests of fresh graphite hold this out. Even simple erosion of radioisotope-laden graphite would be awful, of course (especially in this case where the graphite is in direct contact with the nuclear reactants and daughter products), but it's hard to deny the Soviet field reports. In all likelyhood, fresh nuclear-grade graphite doesn't burn well, but after it is bombarded by high energy radiation and corrosive chemicals for long periods, it does.
2. There *Is* water in the system of most PBMR designs. As I stated, helium is the primary coolant; however, some use water as a secondary coolant in the core (such as China's design), and even some designs that don't use it in the core have a secondary loop in which water is pyrolized into hydrogen and oxygen.
3. "seven layers of containment". Um, yeah right. There's only one pressure-tight containment level in PBMRs. The graphite isn't pressure tight - it's just a coating, and one that gets highly contaminated in the process. The reactor vessel and associated helium loop and pellet recycling are pressure tight. Unlike most nuclear reactors, the reactor building is not a positive pressure structure.
4. "Without the helium moderator the chain reaction stops". This is called "a negative void coefficient", and it's nothing remotely new. Three mile island had a negative void coefficent too. The problem is that the reactor core, even if *all* reaction were to cease, still has a huge amount of heat inside of it, and this residual heat is what poses the threat. By the way, helium is not a moderator - graphite is. You'll note that in demonstrations, the only thing that they demonstrate is shutting down the helium coolant - they never violate the integrity of the pressure vessel. This is because oxygen (and even potentially water or steam) can get in, and this can have very serious consequences. And, without a containment structure...
5. "Gas moderated reactors are a means to make Thorium breeders" - Once again, the term is "gas cooled", not "gas moderated". Do you even know what a moderator is?
Next to my desk we have an Ire Extinguisher. Our boss is really assertive, so we like the idea of having it.
And the fears over Three Mile Island are just plain ignorance. It was a minor incident that didn't hurt anyone. Don't believe me? Too bad. The Pennsylvania court system does. After years of litigation, the courts ruled there isn't enough evidence anyone was harmed by the accident to support even going to trial.
My favorite quote is, "The court has searched the record for any and all evidence which construed in a light most favorable to Plaintiffs creates a genuine issue of material fact warranting submission of their claims to a jury. This effort has been in vain."
Here's a link to the ruling - Click Me
Oh, Edmund, can it be true? that I hold here, in my mortal hand, a nugget of purest green?
You're probably thinking of Mr 'Unit-of-Energy' himself, James Watt. However, he didn't invent the steam engine. The modern idea comes from the late 1600s and industrialised by Thomas Savery and Thomas Newcomen. However Watt did make them around 75% more efficient with a simple change to existing engines, pretty much kicking-off the industrial revolution. Pretty neat stuff!
But yes, Stirling engines should definitely get more press; I doubt 1 in 50 people here in Scotland know of them and might only guess they hail frae doon the road thanks to their rather Scottish name.
"breeder" still manages to refer to several different types, so there isn't a blanket answer. Ordinary "breeders" still have that same *potential* problem, but we don't just have "ordinary" breeders anymore.
While the current fad seems to be over PBMRs, maybe because of the neat name I guess, my favorite still remains the Integral Fast Reactor, not only because of safety features, but because these could run for decades just by burning all the spent fuel from our conventional reactors. Newflash: we don't *need* a hole in the ground for most nuclear waste, just chuck it into an IFR.
Incidentally, the 37-foot diameter units described in the article generate 25 kW each - I wonder if they'd be suitable for domestic use?
Maybe you never had the misfortune of having to clean up after a nuclear accident? And maybe he had access to a lot more information about these accidents than you or I ever will? I dunno, that's why I asked if anyone knew why he banned breeders. Apparently, it was an attempt to hinder proliferation of weapons-grade plutonium, a subject I suspect never came up in your nuke power training...
Cite source for clean-up as the Navy had not yet had one accident by the time he was discharged. To this day, we are still waiting for a screw up.
I never said it was a Navy screwup. Non-Navy screw ups galore.
Money for nothing, pix for free
Any solar technology that doesn't use silicon is definitely a good thing these days. The Photovoltaic industry is the "poor cousin of the microchip industry", and so microchips get all the good silicon while PV gets the leftover crap that Intel et al. don't want. For this reason, and a general shortage of poly-silicon, there is a huge shortage of PV panels all over the world. Germany and Japan gobble up all they can and at a fair price too, leaving hardly anything for the rest of the world.
It's good to see the Stirling engine being used like this because in my opinion, the PV industry has some serious problems, especially if they have to compete with the Slashdot crowd for silicon!
The atmosphere is about 18 ppm neon. That's one resource that's not going to run out.
Sustainability and energy independence essay
So..
(shaking rust off memory)They ran the power (heat) output of the core low. Over controled it below min levels, decreased water flow, cranked up the power by pulling some rods to get power up. Power ran up to high side, dropped some rods in, added water too quickly, cooled core too much, no steam output, turbines stall, tech panics and pulls ALL of the rods (big no-no, he forgot to RTFM), core temp climbs, water cannot be provided quickly enough (no power), water flashes off into steam, core over heats, ignites graphite - boom. More or less.
A nice feedback loop they they magnified causing increasing excursions with ever larger over corrections - doh! Current reactor designs use the working fluid ( or intermediate heat transfer fluid) as the moderator; the reaction cannot proceed with out the moderator being present to slow the neutrons. If the fluid drains out, the reaction halts and the reactor cools. If the reactor gets too hot, the moderator boils off, again halting the reaction. Kinda hard to get into a meltdown condition.