Slashdot Mirror
Tech That Will Save Our Species - Solar Thermal Power
NoMoreCoal writes "Salon has up a story by Joe Romm, former undersecretary of energy during the Clinton administration, discussing a lesser-known alternative energy solution. It's a technology that (he claims) is ready to provide zero-carbon electric power big, fast, cheap and (most importantly) right now: solar thermal power. 'Improvements in manufacturing and design, along with the possibility of higher temperature operation, could easily bring the price down to 6 to 8 cents per kilowatt hour. CSP makes use of the most abundant and free fuel there is, sunlight, and key countries have a vast resource. Solar thermal plants covering the equivalent of a 92-by-92-mile square grid in the Southwest could generate electricity for the entire United States. Mexico has an equally enormous solar resource. China, India, southern Europe, North Africa, the Middle East and Australia also have huge resources.'" Interesting stuff, even if he does mention the Archimedes Death Ray.
The difference between solar thermal power and more well-known solar photovoltaics.
Amnesty International
My blog
No, it doesn't.
Check the summary again. It says "equivalent", not one big 92x92 plot of technology. If the solar fields could be made smaller, but many more spread out over the region, you could get the same effect as if it were one large setup.
I heard about this on NPR last week, and this same concern was brought up. No one is saying that they are going to make such a huge array (can you imagine the need for maintenance workers?). However, if there are enough arrays created, it can be the functional equivalent of the 92x92 field spoken about.
Thunder
No
Has anyone even read the summary? It says plants. That means more than one.
Solar thermal plants covering the equivalent of a 92-by-92-mile square grid
There are some pictures of the German plant here.
The big difference of course, is that there are commercially operating solar/thermal power plants running - with a cost of ~15cents/KWh. Nobody has an operating fusion plant dumping electricity into the grid - dito with antimatter.
Given that the existing plants are experimental, it is entirely possible that future plants can improve efficiency - through improved design/scale - to drop the price to between 6 & 8 cents.
2) No doubt it would change the local environment, but considering it's currently desert the change would probably improve conditions for local wildlife. Add shade, decrease ground temperatures, maybe even help retain moisture in the soil.
3) High voltage DC transmission can send electricity thousands of miles while maintaining acceptable losses. About 5% per 1000 miles. You can't do it with AC because such long cables have huge capacitance that makes reversing the voltage 60 times per second rather difficult. Also, there's less issues with synching the AC waveform with whoever it's connected to - local inverters do that. Why not simply build a nuclear powerplant closer to the consumers? 1) NIMBY - everybody wants it but yet nobody wants it.
2) Waste is still an issue, since the USA is scared shitless to reprocess nuclear waste (it's actually illegal in this country thanks to anti-proliferation legislation).
=Smidge=
This estimate for solar power does not include transmission losses, and assumes you can losslessly transmit power from mexico to alaska (which is a location where you couldn't place this power station).
... (high estimate includes a demand growth of 3.5% per year, which is the expected value if energy prices remain constant at higher demand, which is presumably what you want to do, especially since the alternative is letting people freeze)
So in practice, even today, we'd need at least 120% of the stated figure. If all in one plant we'd need 300%.
So you need 12200 square miles for to even start.
Note that this is already bigger than some states. Let's perhaps put this in a better perspective : this would take 0.3% (low estimate) of the surface area of the united states, 1% for the bad estimate.
How long could one do this ? Well in 235 years the entire surface area of the United States would be necessary to generate energy (again : low estimate).
Half of the surface area would be used in 200 years. A small table :
Year - Area Used (low estimate) - (high estimate)
2008 - 0.3 - 1
2055 - 1 - 5
2084 - 2 - 15
2120 - 5 - 50
2141 - 10 - 100
By contrast, energy generation by new generation nuclear power plants will last, with the large growth, over 600 years, with current technology, with thorium reactors, with negligeable surface area used. In that time, they will generate only 500 tons of problematic waste, ie. nothing we can't handle. And if we still don't have fusion power by then, well, then nobody can say we didn't give the scientists as much time as possible to study it.
And obviously, nuclear power works in Alaska too. Alaska receives only 16% of solar energy, so to power alaska you'd need an 8x bigger solar station.
Of course, it begs the question: How much of our current resources will it take to create/maintain these plants?
;)
When they say '6 to 8 cents per KWh', it generally covers construction, O&M costs. Resources generally abstract out to dollar costs.
Basically, they generally assume you get a loan with a payoff duration of the expected lifespan of the plant. Say 20 years. They figure O&M will cost so much per year, and so many KWh will be produced. Simple division gives you O&M cost per KWh. Then you figure in the annual loan payments*. Divide and you get an expected infrastructure cost for the plant per KWh. Add the two. 6-8 cents per KWh isn't actually that bad. It'd be economical in California, for example, if not quite there for North Dakota(besides the whole 'less sun' thing).
Let's do a bit of comparison with what I think we need more of, nuclear plants.
$1 Billion, 1 Gigawatt plant. 90% load factor. Let's say 4% interest, plant life 40 years.
The interest and capital will be $50 million per year. (4.18M per month)
Random webpage says $50M for Operations
NEI says 1.26 cents per KWh, including fees for eventual disposal and decommisioning.
We can expect our plant to produce about 8B KWh a year. This translates to $100 million O&M per the NEI. I'll use this one.
This all translates to nuclear being around 1.9 cents per KWh. In comparison, I wouldn't say that this would be economical. Even if you knock the nuclear plant down to 20 years, it only increases the cost pre KWh to 3 cents.
*I often use a mortgage calculator that you can punch in duration, interest rate, and amount and it gives you monthly payments. It's intended for houses, but works equally well for cars and billion dollar nuclear plants.
I don't read AC A human right
Just to make something even clearer: you should read the article and learn something before recycling canned opinions.
An essential feature of solar thermal power is that it easily and efficiently stores solar energy directly as heat. From the article:
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
You know, sometimes it helps to RTFA. One of the specific advantages of this type of system is that the energy of the sun is not directly converted to electricity, as it is with solar cells. Rather, the energy is used in the form of heat, which in turn is used (via heating a fluid) to drive a generator. That means that you don't need to store electricity - you need to store heat so that the heat can be used to drive the generator during times when the sun is not available. The article specifically mentions using oil or molten salt to store the heat. Heat up oil or molten salt, store it in well insulated containers, and it will stay hot for a very long time. When you need it, you run the hot oil or salt through a heat exchanger, extract the heat and generate more electricity - all while the sun is on the other side of the planet.
"The legitimate powers of government extend only to such acts as are injurious to others." Thomas Jefferson.
No, you'd need 8464 (92 * 92) different plants 1 square mile each. Not all parts of the country are as suitable as the desert areas are, so you'd need even more if some were going to be in the cloudier areas.
If you're constructing a Dyson sphere, why on Earth (HJARF!) would you bother to haul the building materials up out of Earth's gravity well? Off the top of my head, I have no idea if there's enough asteroid material to build a Dyson sphere at roughly the Earth's orbit. But there's almost certainly enough to build a Niven ring, and by the time we reach that point we could probably start dismantling the outer planets if necessary...
"The legitimate powers of government extend only to such acts as are injurious to others." Thomas Jefferson.
Actually, based on some off the cuff calculations...
.2 sq miles.
Current solar acreage is probably small. A very large solar plant takes
http://www.metaefficient.com/news/north-americas-largest-solar-electric-plant-in-switched-on.html
http://www.metric-conversions.org/cgi-bin/util/convert.cgi
Electric Plant
It looks like electric plants maybe about 75 acres to 170 acres.
(various google "electric plant acres" results.
Say 125 acres average.
http://www.eia.doe.gov/cneaf/electricity/ipp/ipp_sum.html
350mw per plant (19,300mw/55 plants)
604,514 = 1727 electric plants currently
This equates to roughly 300 square miles of electrical plants currently. I'm not sure if the gov site includes dams, windfarms, and nukes. I know windfarms get pretty big (google: 40000-Acre Wind Farm (~62 sq miles), 2000 turbines over 200000 acres (~310 sq miles), Indian Mesa wind farm situated on 34000 acres in West Texas).
She was like chocolate when she drank... semi-sweet at first and then increasingly bitter.
Before reading the fine article, I thought it would be a PR piece for Ausra.
If you read the stuff at their website, http://ausra.com/, they answer a lot of the questions that have been, and doubtless will be asked here;
It's possible to store thermal energy and use it to produce electricity at night.
Some places do receive more sunlight than others, and plants built in those places would be more efficient.
They have a nice PDF that shows (among other things) the normal solar radiation for different areas - plants work better in deserts than in river valleys, but there are plenty of places you can build them that are cost effective.
Ausra isn't vaporware - they already build a plant in Australia, and they are building one in southern California.
The current plant is cost competitive with scrubbed coal, and future plants are supposed to be on par with unscrubbed coal plants.
That last may be hype, but at the very least they can already produce electricity for less than 12 cents a kilowatt, and cutting that in half doesn't seem unreasonable.
Even so, at best these kinds of plants will only supplant oil and coal burning electric plants.
We're still going to burn oil in our cars, home heaters, etc.
Disclaimer: I am not affiliated with Ausra, but most of my information about them comes from them, or their press releases, so take it with a grain of salt.
-- Should you believe authority without question?
Read up on power losses on high power transmission lines and superconductors; then you'll understand how they make sense in limited installations.
- Mike
Once you've lost your temper, you've lost the argument - Me
I 100s of millions , no where near trillion.
It is actually pretty simple to build, doesn't require any new materials, and is simple to maintain.
"More if you factor in the need to store energy overnight and on overcast days."
It's not battery storage, it's hot liquid storage in tanks. Which is released into the turbines on demand.
An area the size of a football field will produce 300 MWatts at the beginning. Cloudy days don't impact this things as much as you would think.
This is NOT solar panels.
About 5 months ago I did a lot of research into this technologies, it looks very promising.
The Kruger Dunning explains most post on
Oh, yeah, this is being researched. In the Netherlands, they are thinking about putting an island in the North sea and put a windmill park around it (usefull for damage repair as well). Now use the energy to pump out water from a big hole in the middle of the island, and use generators when you let it flow back in. Much easier and cheaper and less ugly than building a big tower. Sometimes you wonder why you don't think of things like this yourself.
Wow... Where to start with this topic. I'm by no means an expert in the subject of power, but I have been studying it for approximately a year now (as an electrical engineer) and know people who work in the industry, etc. After reading many of the comments, I just wanted to try and clear up a few of the possible issues I see with this new source of power.
Before I get into that though, I want to briefly discuss how power is produced today, since there seems to be a lot of misconceptions about how things seem to work.
Power utilities today have quite a few resources to generate power. The "base load" power that everyone seems to talk about these days comes from large generation units that maintain a continuous, rated power level 24/7. The reasons for this are usually economical, but can also be based out of safety concerns for things like nuclear power. Depending on the area, the remaining power is usually generated with generation units that are committed a few days in advance (although it is possible to get a generator started from a cold start in 1-2 hours) All generators have ramp rates (the maximum amount the power can change during a given period of time), so they are unable to change their power outputs instantly. In cases where the load demanded by the consumer starts to creep above that being generated by the power plants, peaking stations (normally natural gas based) can come online and are able to respond to the load change. Natural gas, while effective at being able to keep the power generation and load in balance, is expensive, so peaking plants normally don't operate unless power prices are high or it is necessary to use them.
If the load drops for any reason, power plants are capable of throttling down their power generation (again, subject to ramp rates) to approximately 10-20% of their rated output. Anything less than this and the unit will be forced offline (because a minimum level of stream production is necessary to turn the turbine, etc) Although this is one method of regulating power, generation units have a cost curve. The rated power is where the cost of generation is a minimum. Above and below that point, cost starts to rise, sometimes dramatically.
Alternative resources like wind are used, but not heavily due to the nature of their power production. With modern forecasting techniques, operators are able to predict fairly accurately what wind patterns will be doing 3-5 hours in advance. The major problem occurs when the wind stops blowing. Even though we know 3-5 hours in advance that we need to generate more power, it takes a lot of effort (and money) to commit a bunch of generators to make up the shortage on such short notice. Because of this, wind power tends to only make up a small percentage of total power - so only one or two generators need to come up to make up for any shortfall.
So what does this have to do with the current topic you ask? What the article seems to suggest is replacing the multitude of fossil fuel based generators with a few solar power generators. While this may look good on the surface, in reality there are many problems.
The first thing that comes to mind is reliability. People take for granted just how reliable the North American power grid is. In many countries of the world (such as India), power producers cannot meet demand and must make sacrifices to various areas (usually rural) to keep the load balanced. For most modern generators, it's not unreasonable to assume a 1-2% outage rate a year. With multiple smaller generation facilities, this isn't much of a problem, since it is easy to make up the shortage by bringing another generator online. Normally, the system has "reserve power" in the form of generators that are online but not producing power. These generators must be able to start producing power in 15 minutes or less. So, if a generator fails, another generator will be brought up in its place and within an hour should be producing the full amount of required power. In the ev
Here in Spain, the energy companies are forced to buy your surplus at a cost higher than market value. I think it is pretty much the same all around Europe.
And yet not many people install PV. (??)