In case you missed the news, last Tuesday was a monumental day in the solar power world. A contract was signed between Southern California Edison and Stirling Energy Systems to build the world’s largest solar generation array.
The arrays is so large, it will generate more electricity than all the other solar projects in the U.S. combined.That is not the only thing unique about this installation. It DOES NOT use photovoltaic cells. Instead it uses 37′ parabolic mirrors focused on Sterling engines. Sterling engines work on temperature differential. The heat from the sun warms one side and the other is cool.
To give you an idea how large each collector is, here is one with our anti-environmentalist, oil business controlled President in front of one.
When completed, the array will generate 500MW or roughly enough to power 40,000 homes. It will cover 4,500 acres or about 7 square miles. It will be in the top 3% of all generation systems in the state of California.
Which brings us to the next topic… tradeoffs.
It will be based about 70 miles north of Los Angles which is one of the few places a project of this size is feasible. Commercial solar power is really only viable in the Southwest and you need a mix of high demand in fairly close geographic proximity to enough open area to support a project this size. Yet even with obvious limitations on daylight hours and sun time, this will be the first large scale commercially viable solar project.
I found one more tidbit that made this article noteworthy:
Initially, Stirling would build a one-MW test facility using 40 of the company’s 37-foot-diameter dish assemblies. (Each dish generates 25 kilowatts.)…
That number jumped out at me because 25kW would normally power about 2 homes. (assuming it ran 24hrs) Even with solar’s inherent limitations, it looks like one of these could power a single well constructed, energy efficient home. Of course you need enough room to swing a 37 foot dish that tracks the sun; so maybe it would not be a solution for your average suburban 50 x 100 foot lot but in more rural areas, it might finally be feasible to use solar as your primary power source.
(and the winner of last week’s Tech Tuesday contest announced below)
]]>< 
That boys and girls is a whopping 512K of 18 bit parity memory swiped from a DEC PDP-11. That much landscape today could probably fit a half a terabyte of memory instead of half a meg. Anachronda was the big winner based on his multiple posts.(remember most complete answer won) I emailed the addy he plugged in but got no reply. If he does not email in the next week sometime we’ll find some other way to give away his 50 bucks.
A) It’s “Stirling”, not “Sterling”. The significance of this is that a Stirling engine is about 30% or so efficient vs the at most 10% efficiency of solar cells.
B) I sent a couple of replies to your message; one detailing the reasoning behind my guess and the other pointing out that was, in fact, a guess and not certain knowledge.
Looks like a death ray to me. Are you sure Bush isn’t urging that it be pointed at Howard Dean’s house?
–|PW|–
4500 acres? That seems like a HUGE area.
Mechanical work derived from heat energy can never be 100% efficient. So, although one of those might generate 25kW of heat energy, all of that can’t be used unless the system operates at phenomenally high temperatures. There are probably other system losses as well.
Theorectical max efficiency is roughly
(Toperating – Tatmosphere)/Toperating where all temps are on an absolute scale.
I wonder if they mean they’re going to put it near the other two ‘commercially viable solar projects’ that are located out there but are now defunct, but are interesting to see when I drive to Las Vegas from the central valley.
The last one also used a solar array but directed them at a tower filled with some type of salt that would, I believe, then be use to heat water for a steam turbin.
When completed, the array will generate 500MW or roughly enough to power 40,000 homes.
snip
It will be based about 70 miles north of Los Angles which is one of the few places a project of this size is feasible.
I dunno. There are probably other places with 40,000 homes near areas with 2.7mi x 2.7mi (4500 acres) of undeveloped land.
Seems like 4500 acres is about 7 square miles. Not THAT huge.
So now Bush has an energy plan, is backing solar power and is trying to reform Social Security. Don’t tell the libs, they still long for the Klinton days of going out of your way to accomplish absolutely nothing. And Kerry has such a huge body of work in the Senate for us to marvel.
Congrats Anachondra, I’m surprised that my guess (one of my guesses) of the PDP-11 was correct. I chased a wild goose in the wrong direction for a bit. It was fun, though.
John, what makes you think they’re talking about the heat energy? If you’re talking about an electric generator, that’s not the sort of thing you would normally mean when you say it “generates 25kw”. Further, you would normally talk about capturing heat energy from the sun, not generating it.
A 37 foot diameter dish covers about 1075 square feet or about 100 square meters. In my neck of the woods (roughly 100 miles NE of LA, or a bit farther into the desert than they’re building this) we’re supposed to average about 6000 Wh per square meter per day, so this should get about 600kWh per day.
>It’s “Stirling”, not “Sterling”.
Crap, I’m the King of typos. At least I got it right 50% of the time. ;-P
ha- ok 75%
Ya know, the “generates 25kW” statement is just plain not clear. I’ve been assuming that it means it might peak out at 25kW around noon on a summer day. But 600kWh/day is roughly 25kW for 24 hours solid. So maybe they are talking about how much heat energy it captures.
Hmm.
Sure you can talk about energy efficiency all you want, but you realize that heat from the sun is waste heat anyway…it is coming at us whether we want to or not.
This reminds me of when we were discussing efficiency of geothermal power plant installations. The efficiency doesn’t matter as much when the heat is coming anyway.
Not only that, any time you talk about waste heat, whether it is diesel engine jacket water heating up evaporators on ships, or exhaust gas boilers on the exit end of deisel engines or gas turbines for COGAS or COGEN systems installed in power plants or ships, the adsorption refrigeration cycle, or even the Stirling engine as is mentioned here, sure efficiency is important, but only to a point, the heat is free.
Remember solar energy is free (as long as the sun is pumping out massive amounts of radiation…and will continue to do so for hundreds of millions of years, if not billions).
oops I forgot to mention…
I said “we” I meant my class. We were discussing geothermal power plant installations in a class called “Energy Systems Design” my last semester of my senior year studying mechanical engineering (I now have a B.S. in it as of 04/05)
That’ll last until some Wilson’s lesser fringe-footed blue tongued sparrow stork flies through and does the Easy-Bakeâ„¢ thing. If that doesn’t happen before it gets into operation the local increase in temperature readings will force them to build two with the mirrors pointed up to reflect sunshine back into outer space just in case average temperature levels increase .00001 degrees in Siberia.
oh an Anacondra…
kW is a unit of power, not energy
1 kW is 1 kJ/s
or in the terms of energy most people are used to (from power bills)
1 kJ is 1/3600 kW-hrs
so maybe they stored 2160000 kJ, or 600kW-hrs per day, then divided that by 24 hours and derived that number of 25 kw.
Home solar collection is feasible; in fact, BP Solar has teamed up with Home Depot in this area to offer it. Tax breaks help to make it possible to break even in a few years depending on your exact circumstances. However, the key is that you really need to stay on the grid so you can draw power when you’re not generating; and to really save money, you need to be able to deliver power back into the grid when you’re generating more than you need. (Yes, your meter runs backwards.)
Alternatively, you can keep battery storage on-site to help smooth out availability. But if you want to stay off-grid completely, you’d better be in a very sunny locale, and you’d still better have a backup generator, preferably with automatic cutover.
Henry, I agree. When you’re talking about clean, renewable, plentiful energy sources, efficiency really is not an issue. That’s why I really don’t worry so much about the efficiency of a hydrogen-based energy distrubtion system, as long as we consider renewable energy sources such as solar and nuclear to free up the hydrogen.
bullwinkle—I know you’re joking, but in fact, it seems to me that a massive solar array would reduce temperatures slightly in the area, because it is converting energy that normally would have been dissipated as heat into electricity.
Maybe this is dumb, but I’ll throw it out there anyway. I ran across the idea in a book a long time ago that solar energy has an inherent problem/danger that is directly related to the inefficiency of any given solar power system.
Very briefly, deserts reflect a certain amount of UV and visible radiation back out into space. If we absorb that radiation with solar panels, we trap the energy in the atmosphere. Then, any heat (i.e., IR radiation) that is released (either due to unavoidable losses or via actual use of the energy) will help heat up the atmosphere.
I know, I know…Global Warming, right? It just always stuck with me because environmentalist types (especially the wacko fringe) tend to take it for granted that solar power is ‘clean’. I’m not so sure it is. Certainly there’s no soot…but how much heat will be trapped in this way? I don’t know. Does anybody?
Tom, when given the chance, take a heat transfer course. I can see where you’re going, but without a full thorough analysis, we can’t tell. Radiation doesn’t have to be visible light to be transferring. There is thermal radiation, too, and the hotter an object is, the more it will radiate, eventually reaching outer space. What most “global warming” people forget (and I wrote a piece on this a while ago) is that the warmer the world is, the more it will radiate to outer space anyway (as all heat goes, thermal radiation is based on the difference in temperatures:
Heat = (emissivity)(black body constant)*(Th^4-Tl^4)
Anyone who lives in Las Vegas can see one of those 37 foot dishes by driving past the UNLV campus on Sahara Blvd. They have had a test model of the Stirling solar generator there for years. It really isn’t that big and it looks very, very cool. The first time I saw it I thought I had come upon the real world version of the Death Star cannon.
VM
Correction for all of you eager Wizbang gamblers in LV….Flamingo Blvd.
VM
We could solve the global warming problem by rounding up the envirokooks and nuking them, preferrably in central Tehran. Counteract terrorism and global warming at the same time with nuclear winter! On the serious side, I have 75 solar panels on my roof, it’s 22 miles to the nearest power line. I also have a 20 KW diesel generator to keep lights and refrigeration running when it stays cloudy too long. The cost of the panels and batteries and peridoic replacement of the batteries would buy diesel and maintain the smaller generator (not only needs to provide full power for household use but also has to charge the batteries) for more than the 20 year life of the panels. It still takes more energy to make the panels than they can produce in their life. I have the system because I came down here for peace and quiet. It’s a luxury, and an expensive one. Add in the occasional few hundred hurricane-driven coconuts and the economics of it get worse in a big hurry. When Emily passed just north of me last month I lost 9 panels, by the time I pay the freight and the customs duties on them it’ll cost close to $10K.
Efficiency does matter, and matters quite a bit. Because while the sunlight may be free, the materials used to build the collectors are not, the land to be used is not free (gotta pay those property taxes on the land you own rent), and maintenance costs are non-trivial. You have to overcome those costs before it is cost effective. The greater efficiency, the quicker you overcome the costs, and the more reason to use it.
There’s no reason to commit 7 sq miles over to solar energy if the cost to do so is more than it would take to generate the same electricity from coal.
Nathan that is why I mentioned that efficiency is important…but only to a point. When you’re talking about rising energy costs (especially due to the rising cost of oil), and material costs, I can see your point.
However when you’re talking about minute efficiency differences, as long as its breakeven point isn’t somewhere in the long-distant future, what does it matter?
Besides, if you were going to build a power plant that is powered by natural gas or diesel fuel, I bet you the materials would have a similar cost comparitively, but the cost of the FUEL aka the HEAT SOURCE is where you make a lot of your money.
That is when you start doing $$ analysis(e.g. present value analysis) and stuff including installation cost, fuel cost, efficiency IS factored in, but only on plants with fuels that cost money. Otherwise, installation and maintenance is factored against the overall power output of the plant, not “efficiency”.
…oi energy systems design is coming back to me all over again (god help me)
7 square miles to generate 1/10th the electricity
of 1 nuclear power plant.
I’m all for clean energy but I’m still skeptical.
When it starts frying migrating endangered species
of birds, the environmentalists will want it shut down.
Sheesh,
Just wait til the environuts get a gander at this destruction of habitat to build giant mirrors. First the environuts came for the wind power generators off Nantucket and New Jersey and no one said anything. Then, they came for the hybrid vehicles because they didn’t get the gas mileage as claimed by the EPA. Now, they’re coming for these devices because they can.
Oh, and they look like something Dr. Evil would conjure up to be able to get those frickin’ sharks with the frickin’ laser beams. Which is to say, way cool.
Uh, this is a really great idea for the daytime and will probably help during peak power usage (from air conditioners and the like), but I guess the plant will be effectively non-producing during the evening and night hours, right? This is not replacement technology, but supplemental technology. For a “environmentally friendly” technology to start supplanting coal and gas plants, it will have to work 24/7 and approach the efficiency of coal and gas.
That being said, I am glad that companies are trying out alternatives. We won’t innovate if we don’t experiment.
Hey, how come it’s okay with the environmentalists to spoil the pristine status of a whopping 4,500 acres of desert with a bunch of mirrors to meet our ever-increasing energy needs, but it’s not okay to spoil just 11 acres of the Arctic National Wildlife Refuge to drill for oil to do the same?
How come?
Henry partially addressed Nathan’s comments, but you need to factor in the other things he talked about. Like the area required to build a fossil or nuclear plant, the cost of waste disposal, which you won’t have from the solar, the cost of the maintenance of the fossil and/or nuclear plant vs. this installation. This was considered in the design and decision to go forward with this installation.
George has a point as well, although his numbers are a little off. San Onofre, takes up close to the same land area as this array will, and generates 2200MW when both units are running, close to 1/4 is a better number.
Southern California Edison has been one of the largest suppliers and purchasers of alternative energy sources for years. They were involved in the Solar One and Solar Two project that DianeK spoke of earlier, they have run and built geothermal plants, they built and run Hydro plants and they purchase almost all of the wind energy generated in the San Gorgonio and Tehachapi Pass. This is nothing new, especially when you consider that our CEO, John Bryson, was a co-founder and attorney for the Natural Resources Defense Council
Where are the environmentalists? That 4500 acre area is more than twice the size of the proposed drilling site in ANWR, and a damn site closer to both humans and wildlife. But it doesn’t involve fossil fuels so that must make it ok. Ridiculous.
Hey, how come it’s okay with the environmentalists to spoil the pristine status of a whopping 4,500 acres of desert with a bunch of mirrors to meet our ever-increasing energy needs, but it’s not okay to spoil just 11 acres of the Arctic National Wildlife Refuge to drill for oil to do the same?
Because nuclear power is, like, bad. It destroys Japanese cities without being, like, fun to watch on the late show like Godzilla.
Solar power, though, man, I mean that’s like so cool. ‘Cause it’s energy from the sun, man. From the freakin’ sun!
And that’s just too cool for words, dude.
Every time someone brings up nuclear power, every critic brings up 3 mile island, forgetting that that happened in 1979. Safety measures have increased exponentially since then, and other countries have successfully converted to mostly nuclear power (Take France for example, the left’s most heroic country).
I say let’s convert the core base for our power production over to nuclear, talk about getting off a foreign dependence of oil!
(Take France for example, the left’s most heroic country)
Yes, they currently generate over 80% of their electricity from the nuclear option.
They major difference though, between them and us, is they rely on a mostly standard design for most of their plants. This reduces costs associated with licensing, building, maintaining the plants (spare parts are the same) and training the people to run the plants(Train them to run plant A, and they can run plant B and C and . . .)
Here, in the USA, you would be hard pressed to find a standard design outside the individual sites around the country. So, someone who operates a Nuclear Power Plant in California, can not quit and just go operate a Nuclear Power Plant in New York. The same goes for repair and replacement of parts.
Until this country resolves to go with a single design, then licenses that design to be manufactured, the nuclear option for energy generation will be slow in coming.
Uh, this is a really great idea for the daytime and will probably help during peak power usage (from air conditioners and the like), but I guess the plant will be effectively non-producing during the evening and night hours, right?
No problem. All we need is a coordinated global grid of solar collectors managed by the UN.
(ducks)
Hee 🙂 – as long as we don’t have to then depend on France and Joe Wilson to get us uranium out of Niger, I’m all for nuclear facilities.
Why don’t we confiscate the stuff from Iran and North Korea?
err moderators…
[Done- Here and the other place you goofed up too. 😉 P]
Well we have finally got a topic that I know a bit about – the production of energy. Any alternative source of energy is good for a lot of reasons. However, we have to look at the practical side of producing energy – that is the actual delivery and production of a product that is consumed almost the very second it is produced. I know a lot of you would not like turning on your computers, lights, or TV and having to wait until the power reached your homes.
Conventional power – generated by fossil fuels, hydroelectric generators are all controllable – that is the power output can be moved as needed – both up and down. They can be sited, to some degree away from the load centers (your homes). Alternative fuel generation – like solar and wind does not move well. It is either on or off. I can control the output of a wind farm by limiting the number of wind generators on line but once on, its all or nothing. Another factor especially with wind is that you get what is there – if the wind is light – you get little output – if the wind is high – you get more output – if the wind is really high – you get zero! They shut down for safety.
Solar is much the same – on or off – output depends on amount of sun. Not really controllable. Good for the environment, but not good for the operators controlling the power grid.
Another thing is that the more we add to the system with non-controllable generation, we also loose the amount of VAR production. What’s a VAR – well its really apparent power – not real, but boy is it needed. Without VARs electric current in an AC circuit does not flow. VARs help with voltage, among other things. Low voltage – your electrical equipment will get damaged.
We can install capacitors on the AC systems, or other VAR producing devices, but they tend to be static devices, and not that helpful on a very hot day when we need to maintain good voltages so you can have power. We get most of our VARs from generators. This is dynamic – which means we can control the VAR output of a generator just as we do the energy.
Basically we need a mix of both – alternative and normal sources of generation to control the system in a safe and reliable manner. I’m for alternative sources of power, but we have certain limitations that must be overcome before solar or any other alternative power source saves the day.
Interesting Point JATOj, I completely forgot about power factor and the role that it plays. Power Factor in Alternating Current Power is the relation ship between Real Power and Apparent Power. Apparent Power (or KVAR as JATOj mentioned) is the power generated, and Real Power (or kW, is the power the load actually sees).
P.F. = kW/kVAR
Anyways, just to let you know in a purely inductive load (anything with windings is going to induce a voltage, so transformers and motors are more of an inductive load, but not entirely one) the current is lagging the voltage by 90 degrees, and in a purely capacitive load (as evidenced by batteries and a few other pieces of equipment with capaciters in them) the current is leading the voltage by 90 degrees. However, the majority of loads aren’t pure. As an example, most generators that I am aware of (I’ve only dealt with generators on ships), the power factor is 80% lagging (0.8 lagging), due to the nature of the load, the transformers and motors mean that more of an inductive load is present (and it varies based on the time of day, too: when purely resistive-sometimes with slight capacitive- loads come on like lights, the power factor increases more to 1).
What does all that have to do with power generation? Well in order for this system to be viable, there needs to be enough room on the grid to be able to take the load, or some units will have to be shut off (and that just gets annoying). What could work is to install capacitors somewhere along the line that can hold voltage (capacitors act like accumulators in a hydraulic circuit, they hold voltages like an accumulator holds pressure), even though it will mess with the power factor, and that is what JATOj is talking about.
To claim that this solar array will produce 1/4 or even 1/10 the power produced by an average sized nuclear plant is total lunacy.
I will bet that the kWh output of this boondoggle will never reach 1/100th of the output of said nuclear plant.
The thing is, if these alternative energy nuts were honest, they would publish output and net energy produced vs. energy consumed in plant construction data.
Believe me, I’ve looked, and the data isn’t published.
I wonder why that is???
Henry,
I was once doing some work for a customer and his electrician was installing some massive equipment. I asked the electrician about the PF of the equipment and if the local utility measured it and changed accordingly.
The electrician all but cursed me out and said there was no such things as “Power Factor” and that I was making it up.
So we called the local utility up and they said that they would not be installing at PF meter today but they would probably be changing it in the future. After we hung up the guy says, “Well they never taught me that in electrician school” to which I (as a then punk kid) replied “That’s why you go to engineering school.”
He was real pissy with me for the next few day but after that he sorta realized that I might be a punk kid but I held my own. We’ve worked for years since then and he rarely doubts me.
BTW that was (cough) a long time ago and they still haven’t changed the meter.
Heh, thanks Paul…yea that’s kind of a funny story about an electrician not even knowing what the hell power factor was.
I live in the southern half of california, so I’m more than aware of Southern California Edison… Theirs is probably the huge wind farm between Tehachapi and the Mojave desert (where Edwards air force base is), and other power production facilities around the area. The article stated that SCE is the “leading alternative power purchaser in the nation”. God I hope they do it anyway. California’s energy crisis years back led our previous Governor to sign us to long term high paying contracts for outside of state energy (messing up the budget for years to come).
Heh, on the subject of power factor, I had to double check in my “electrical engineering” textbook about the power factor leading being current leading the voltage..it’s been a while, and when you’re learning what else is going on to run a ship from scratch…you tend to forget minor details like that (for example: when you parallel generators, you match the speed, match the phase-with a syncroscope-…parallel the generator by bringing it on the bus, then balance the kW by adjusting the governor setting, then balance the kVAR or P.F. by adjusting the exciter voltage setting).
RE: pennywit’s wit (August 16, 2005 12:18 PM)
Looks like a death ray to me. Are you sure Bush isn’t urging that it be pointed at Howard Dean’s house?
No, no, no… it’s a clone ray. The VRWC wants to destroy the Left, not help it.
Actually, a 25kw generator could power 15-25 homes.