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Mixing Coal and Solar To Produce Cheaper Energy
Al writes "It might not please many environmentalists, but a major energy company is adding solar-thermal power to a coal plant and says this could be the cost-effective way to produce energy while lowering CO2 emissions. Abengoa Solar and Xcel Energy, Colorado's largest electrical utility, have begun modifying the coal plant, which is based near Grand Junction, Colorado. Under the design, parabolic troughs will be used to preheat water that will be fed into the coal plant's boilers, where coal is burned to turn the water into steam. Cost savings comes from using existing turbines and generators and from operating at higher efficiencies, since the turbines and generators in solar-thermal plants are normally optimized to run at the lower temperatures generated by parabolic mirrors."
It turns out that you can turn CO2 into fuel by exposing it to a titanium oxide catalyst in the presence of sunlight. In a closed cycle, this would be a carbon-neutral way to go. http://dsc.discovery.com/news/2009/03/23/carbon-dioxide-fuel.html
What part of "A well regulated militia" do you not understand?
It turns out that you can turn CO2 into fuel by exposing it to a titanium oxide catalyst in the presence of sunlight.
That's just another form of solar power, it's just you're using the sunlight to produce fuel rather than electricity. If it's more efficient than solar electrical generation (very possible) then it's a good idea, it's bound to be more efficient than biofuels, but whether it's more efficient than solar water heating, I don't know.
You'd probably need a concentrated source of CO2 for that, so it would either reduce efficiency, by using some energy to concentrate CO2, or would use existing power plants outputs, meaning it's not carbon neutral.
Everyone should read this http://www.withouthotair.com/
Within the US, MTR mining is almost entirely an eastern thing, and for the most part, eastern coal has nastily higher sulfur levels than western coal.
Almost everything out west is either underground mines (as is true for the mine that feeds the Cameo plant in the article) or strip mines out in the middle of flat boring nowhere Wyoming. Compared with the destruction caused by MTR mining, neither of these is particularly objectionable.
>Reducing coal consumption by 80% or so by having solar provide heat
The article says:
"At the most, the contribution from solar power at existing plants will probably be no more than 10 to 15 percent of the electricity produced." "For the Colorado project, the share will be more like 3 percent"
Although I agree with the spirit of what you said, it is not THAT much contribution by solar :)
The risk of uranium in the air is not that it will release alpha particles that will travel miles and kill people. The problem is that the uranium will be inhaled or ingested, become incorporated into people's bodies, and then release alpha particles that are very likely to interact (as your post correctly indicates they will) with the molecular constituents of cells. Exposure to external alpha-emitters is safe, but internalization can cause cancer (or be acutely devastating, depending on the dose - see Litvinenko and Po-210, an alpha-emitter). That and the fact that thorium and uranium are toxic heavy metals independent of their radioactivity.
I agree, 10 years ago no one was going to try and sell a all-electric car.
False.
-- If you try to fail and succeed, which have you done? - Uli's moose
Actually, the numbers I've seen don't support the idea that there is enough Uranium in the ground to last, quite, that long, especially at current prices. However, there is that much uranium in small particles spread throughout the world's oceans. Should the price of uranium go up by a small amount, it will be cost effective to implement the more expensive technology needed to tap that source. Also, since fuel prices are a minuscule percentage of the total cost of operating a nuclear power plant, the price of the electricity should see, virtually, no increase.
Rules of Conduct:
#1 - The DM is always right.
#2 - If the DM is wrong, see rule #1
A coal plant has scads of waste heat
Let me fix that for you:
A coal plant has scads of low quality waste heat
Don't forget, your waste heat is what's necessary to condense the steam on the other side of the turbines. You *must* have some waste heat, otherwise there's no heat differential, thus no mechanical work can be extracted.
From wikipedia, "While customer reaction to the EV1 was positive, GM viewed the program as evidence that electric cars occupied an unprofitable niche of the automobile market, evidenced by their ability to lease only 800 units in face of production costs of US$1 billion over four years." Granted they tried to lease and not sell, but only 800 units leased over four years is small no matter how you cut it. And with only a 55-75 mile range, they only appeal to some urban and suburban dwellers.
Choosing the lesser of two evils is a choice for evil.
So you link to an article which confirms his claim, and label it "false"? In what universe does THAT make sense?
Howso? I linked to an article that notes quite clearly that GM marketed and sold all-electric cars from 1996 to 1999. Hybrids have never been of much interest to GM.
The economics of the EV-1 are hotly contested, given that it was an entirely new platform, and so few were produced. Although I can't confirm the theories that the program was cancelled for political reasons, the allegation is certainly plausible.
-- If you try to fail and succeed, which have you done? - Uli's moose
Marketed .... ok, depending on your definition. Sold ... definitely not, as the article you linked to clearly explains:
On December 5, 1996, GM began delivering the EV1s to its selection of carefully-screened lessees ... Although the car could not be purchased outright, its MSRP was quoted at $34,000.
In the same way that evolution is hotly contested - ignorant people make straw-men arguments and conspiracy-theories persistently raise their ugly heads, while people who actually know what they're talking about shake their heads in amazement.
Again, from the article:
According to Dennis Minano, then-GM Vice President for Energy and Environment, "Is it what our customer wants?"[11] GM was not alone in its denunciation of electric vehicles as a viable alternative to the gasoline car; according to Robert J. Eaton, then-chairman of Chrysler, "The question is whether the market is ready for the product... if the law is there, we'll meet it... at this point of time, nobody can forecast that we can make [an electric car].
None of the automakers expected to create a viable electric vehicle by the set deadline, but they had no choice other than to try. If the EV1 had not been scrapped, it's possible that it may have found a niche-market, kinda like the Segway. Whether such a low level of sales would have been enough to justify development costs is debatable. Either way, it's clear that EV's weren't ready for mainstream use in the 90's - they didn't have the range, they cost too much, and they took much too long to recharge.
Hell, Tesla Motors is having problems making pure electric vehicles TODAY for mainstream use, and they have the advantage of better technology in general, and much better battery technology in particular. I like the idea of buying their sedan once it becomes available, but I'm not a big fan of forking over $50,000 for it. And their financial figures reflect the difficulty of the project - if the government hadn't bailed them out with $400 million, it's likely that the company would have folded.
Given how crappy wind farms are as a power source, I don't think that's a very good example.
There's no single energy resource that is going to meet the needs of the power grid. Coal and nuclear are too slow to follow load, wind and solar are intermittent, hydro, geothermal and biomass are limited locationally. Natural gas is subject to price volatility.
The grid's energy requirements are too big and complicated to be handled by any one source of energy. Using baseload resources to provide the bulk of the energy with intermittent resources to provide cheaper or more timely energy with hydro and natural gas to fill in the gaps is what it is necessary now.
If absolute power corrupts absolutely, what does this say about renewable power?
Don't do that. It's not safe to drink hot tap water, due to the pipes. Be patient, get cold tap, and warm it.
Since using coal releases about 20x more CO2 than fossil fuels and will not run out for hundreds of years even assuming increasing demand, this is bad news for stopping the use of fossil fuels based on economic reasons.
Huh? Coal is a fossil fuel.
The waste heat is currently lost to the atmosphere in the cooling towers. There is no reason not to be running the cold input water through a heat exchanger to recapture some of that waste heat. This is how efficiency works.
The mechanical work comes from superheating the water and letting the steam turn turbines. In other words, you ADD heat - it makes no difference what the exhaust is used for as the work has already been done. There is no useful work being done by having the steam condense back to water other than helping to draw the steam into the turbine. By recapturing some of that waste heat you make the system more efficient. The process does not rely on having ice cold water as an input, just water in a liquid phase. You seem to be confusing a steam turbine with a closed system steam engine, where you need to condense to create a vacuum that actually works on the piston.
To be honest your last statement doesn't make sense anyway. You don't "*need*" waste heat to condense the steam, it is the very thing you are trying to get rid of. In fact you want as little heat as possible to make the phase change quicker. Whether the "waste" heat is lost to the atmosphere or to the incoming cold water makes no difference to the process. In an ideal system you would be getting water out of the exhaust not steam, but as that doesn't work, you need to let the steam condense, but only when you have extracted all the energy you can from it. This is why they reheat steam and admit it to several subsequent turbines before they cut their losses and send it to the cooling towers. Notice that they reheat the steam. It is more efficient to reheat than to heat from cold. The closer the input water is to phase change, then the less energy you need to make that phase change happen. Otherwise there would be no point to this article.