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."

Comments

who would object?

[eighthave]

sounds good to me, donno any environmentalists who would object to burning less coal...

Re:who would object?

[Anonymous Coward]

your answer: its better then coal on its own but might be used as an excuse to avoid making solar/renewable a larger part of an energy plain, such as "we are green, we have coal solar power stations" rather then actually building any wind farms/etc

Re:who would object?

[Rei]

Coal doesn't have to be produced by MTR. One can both object to MTR and support reducing the coal consumption of our existing plants. It's not economically realistic to phase out all of our existing coal plants, but if we can eliminate 4/5ths of their coal consumption, that'd be a huge victory.

Re:who would object?

[ciroknight]

A rabid unshaven hippie environmentalist might bring notice to the fact that this is just spending more money propping up coal, rather than investing the money directly into pure green energy (such as a pure solar thermal power plant replacing the coal burning one). But the fact is, there's no way this money would have went to pure green energy in the first place, so they should really be pleased that they are even bothering to try to green their coal plants at all.

Re:who would object?

[TheGreenNuke]

I don't object to burning less coal, I object to burning coal. It puts Uranium and Thorium into the air. Population radiation exposure is greater form a coal fired plant than a nuclear plant.

Re:who would object?

[SBrach]

I agree, 10 years ago no one was going to try and sell a all-electric car, it wasn't commercially viable. So they designed hybrids instead. The hybrid technology is what has allowed us to build electric cars today. Many "environmentalists" would argue that hybrids are evil because they still emit CO2 but without them we probably wouldn't have the battery tech, regenerative braking, and weight reduction techniques required for all-electrics today. This plant is the same deal. If continuing to burn some coal develops the solar-thermal tech so that it is commercially viable then it is a win-win.

Re:who would object?

[commodore64_love]

So?

Embracing a technology that is 50% solar-powered is still better than 0% solar power. Also many people forget that coal and oil ARE solar power - it's the sunlight that fell on our planet ~300 million years ago, and now exists in condensed form. Our challenge is not to stop using ancient sunlight completely, but to use today's sunlight. Converting plants to partial-solar is one step towards that goal.

Re:who would object?

[TheGreenNuke]

Thats great for U-238, but there are other isotopes. The thing is, coal puts them in the air, nuclear keeps them contained. And you missed the part about how the US has large stockpiles of Uranium. More than enough to power us through the next few millenium, more is we use breeder reactors.

Re:who would object?

[GameMaster]

Actually, yes our challenge is to stop using ancient sunlight completely, eventually. Burning fossil fuels as a significant portion of our energy generation produces lots of nasty air pollution (which is bad for human health and the environment, even if you don't believe in global climate change) and almost guarantees a horrible economic crash once the resources finally start to run out (which will be in the not so distant future considering the amount we consume now and the rate at which that consumption is growing). We can't afford to let industry make a token gesture towards solving the problem and use that as an excuse to keep expanding the use of fossil fuels. Sure, we should let them convert old plants over to using this tech (as well as any other "clean coal" tech that comes along) but we should never allow them to build more plants even if they're using this technology in their construction. The others above are right to be wary of the possibility that the coal industry will use this technology as a red herring to distract from the bigger picture.

Re:who would object?

[bucky0]

There are all kinds of nasty things in coal. You're neglecting all the other (fun!) isotopes that are stored in coal (decay products from heavier materials that are nasty) as well as things that are chemically nasty (arsenic and mercury for one).

I'm not a member of the far left. I'm a physicist. I've worked at some labs with a significant amount of historical radioactive contamination and have had to read up a lot on the subject. It *is* bad. Really really bad. There are isotopes that are (chemically) remarkably similar to calcium. What happens if those chemicals get put into your bones?

Don't extrapolate information like that from wikipedia. Read one of the many articles on the subject. Anyone who has any bit of intelligence will agree.

Re:who would object?

[c6gunner]

So you link to an article which confirms his claim, and label it "false"? In what universe does THAT make sense?

Re:who would object?

[TheGreenNuke]

Alpha particles can do significant damage if the alpha particle producing decay occurs inside the body. He does know what he's talking about. So play with alpha producing particles all day long, but make sure you clean those hands good before you eat and ingest them. It's also not recommend to swallow uranium, but go for it if you'd like.

And last I checked, a filter was not 100% effective, otherwise it wouldn't be a filter, it would be solid metal.

Re:who would object?

[commodore64_love]

WELL AS I SAID (but you apparently didn't bother to read): "this is one step towards that goal". You can not get to the second floor of your house in one leap - you have to take one step at a time. Today 50% solar/50% coal. Next decade 75% solar/25% coal. The decade after that 95% solar/5% coal power plants. Same applies to cars which are 10% electric/90% gasoline hybrids today, but eventually will be 95% electric with maybe a small gasoline generator for long-distance. But I guess shouldn't expect an environmentalist to understand that simple "transitional" principle. They are too busy pushing-over radio towers and then bragging about it - http://www.cnn.com/2009/CRIME/09/04/washington.towers.terrorism/ I tried to make a reasonable statement, but all I got was a slap across the face. You will not win your cause by pissing-off other environmentalists who are on your side.

I drive an 80mpg hybrid, light my house with 25 watt or lower bulbs, and turn-off the heat in the winter to help reduce my carbon footprint - and then some shitheads named the "Earth Liberation Front" go do this. These earth-worshiping religious wackos harm the cause; they don't help it. I'd like to set fire to every one of their offices, and see how they enjoy having millions of dollars of personal property destroyed.

And if they really believe the AM radio waves are interfering with cellphones (impossible) or intercoms (probably but they are second-class devices anyway), then petition the FCC. That's why that organization exists.

Re:who would object?

[BlueStrat]

We have the capacity to keep using fossil fuels for a couple of centuries still, so if we care about the massive self inflicted damage that would cause, we have to stop using dirty fuel sources for that reason, not because it makes economical sense to do so. It doesn't hurt to have cheap available solar cells though.

I'm as much for a cleaner planet as anyone. However, people still have to live and afford to heat in winter & cool in summer. The higher that energy costs rise, the more poor people that will be freezing to death or dying from heat. People have to be able to afford to commute to work and to travel about for all the other things that living in a modern society requires.

Farmers have to use tractors and other machinery to keep the food supply cheap enough to feed everyone. They also need energy to irrigate land (heck, right now California farmers are watching their crops die for lack of water and food will become more expensive and harder to get, especially for the poor/minorities/inner-city-dwellers, because environmentalists want to save a bait-fish rather than feed people). Grocery stores have to refrigerate the food. Trucks have to bring the food to the stores.

That's the disconnect that many environmentalist types suffer. They put a clean environment and animals ahead of the lives of people, refusing compromise so human lives may be preserved and then wonder why they make so little progress.

When environmentalists are willing to seriously damage the nations' food supply because of some perceived risk to a bait-fish's population numbers as in the current situation in California, it makes all the other perfectly reasonable environmental proposals that much harder to get taken seriously by the general public and the politicians. At least by those politicians that need to worry about getting re-elected, as many are in districts with voters that would re-elect them no matter what they did short of turning into Satan Himself on national TV and clubbing baby seals live in HD.

I'm sure there will be numerous environmental groups that will come out against this, as they won't be able to see past OMGZ!! COAL!!! and realize it's a step in the right direction.

Strat

Environmentalists

[treeves]

Why would it not please them...if they are rational?
But maybe the answer is contained within the question....

Re:Environmentalists

[amorsen]

According to the article we're talking at best 15% less coal burned per unit electricity, with no way to scale beyond that. Great for the power plants where it is viable, but definitely niche. Doesn't change the fact that we should stop building coal fired plants and decommission the existing ones.

Why would it not please environmentalists?

[Rei]

Why wouldn't environmentalists be happy with this? I consider myself one and think this is great news. Too many people focus on 100% solutions. You don't need to eliminate 100% of coal in the short term. Reducing coal consumption by 80% or so by having solar provide heat during peak hours (daytime) would still be a huge benefit.

Re:Why would it not please environmentalists?

[Anonymous Coward]

I never understood why traditional power plants need cooling ponds or cooling towers. Couldn't they just use the heat from low pressure steam to pre-heat the water before it goes back into the boiler?

Re:Glad to see the "coalar" tag

[spun]

Coalar energy, let's hope it has the efficiency of coal with the environmental impact of solar, and not the other way around.

Come on people...

[Anonymous Coward]

The solution is nuclear freaking power. Even China realizes this now.

We've been in the Atomic age for 60 years now and still don't have a majority of our energy from nuclear energy. It's such a disgrace.

Re:Come on people...

[WindBourne]

And I am THANKFUL that it is NOT the majority. I want it to be a larger part of our matrix, but we need to maintain a matrix of power. The problem with coal is that it is ~50% of America's power. If it was around 33%, then we would not have these issues. In particular, we would not be worried about the idea of losing more of it. We need more nuclear, but not majority.

Does not make any sense??

[Ancient_Hacker]

This does not make any sense to me. A coal plant has scads of waste heat at high enough temperatures to preheat any amount of water. Exactly where does solar heat fit into this picture? It seems like an expensive way to heat water and as a consequence, let more hot coal gas get away.

Re:Why Would Environmentalists Not Be Pleased?

[Nadaka]

Don't forget nuclear. Be a fan of nuclear power if you want to be green. We need to start building new feeder/breeder reactors. They can use the waste of the previous generation of plants as fuel with a much reduced waste footprint. Combine that with the small area and resistance to adverse climate and it makes a good compliment for other "green" energy.

Wind IMO is not that great for large scale deployment, to unreliable. Though it would be quite acceptable over time for tasks that don't require constant power, such as water purification or hydrogen electrolysis.

Displeased Environmentalists

[Doc Ruby]

If it displeases environmentalists, it will be because it's still really bad for the environment. Using solar to preheat the water instead of more coal to preheat it just admits that solar is a more effective tech for generating energy than coal is. Any coal still burned is still polluting the Greenhouse, creating huge and unmanageable costs just a little down the road (and downwind, the typical "coal is clean" illusion).

They should just convert the entire plant to solar. But coal is too subsidized for them to abandon it, and its lobbyists have too tight a chokehold on the government for solar to have an equal shot at economic efficiency.

Re:Displeased Environmentalists

[The_mad_linguist]

No, if it displeases environmentalists, it will be because it displeases environmentalists. The correlation between things that are clean and good for the environment (such as nuclear power), and the things that please environmentalists is not very strong.

still not clean

[beckett]

There have been many attempts of late to greenwash coal, this solar project and the "clean coal" concepts being the most recent incarnation. Even if 100% of coal plants can be made 100% carbon neutral, where do they get the coal from?

in December 2008, a 40 acre ash pond in tennessee broke through its walls and flooded millions of gallons of coal ash, potentially far worse than the Exxon Valdez. This is one of the largest environmental disasters that has happened in the US, and there has been little to no national coverage about this accident.

There are a lot of heavy hitters in the coal industry that want to put the best possible face on coal (e.g. Montana), and it is alarming that 'mountaintop removal', the laziest way to get coal, is frequently not discussed when considering how green a coal plant can be.

Makes perfect sense

[roc97007]

When I make a cup of tea in the microwave, I can put in a cup of cold water and set the timer for 3 minutes, or I can fill from the "hot" tap, put in a cup of warm water, and set the timer for 2 minutes. Using solar to preheat the water means less coal burned for unit power. Even if you weren't trying to reduce your "carbon footprint", this is still an excellent thing to do.

Uhmmm. No.

[WindBourne]

I was the post above that said I have been trying for nearly 4 years to get Colorado to do this approach. Lets talk economics of this. Many cities have 1-4 SMALL coal plants (typically about 100 MW) that are located in there. Because they were built in the 50-70, they are much older and not as efficient. Many companies want to get rid of them and bring in GW size plants. These monster would be located on the outer fringe and would then have to transport lots of electricity for a long haul. That is wasteful, but it turns out not terribly expensive. With that approach, easterners can get electricity at about .07-.15/kw.. Now, would can AE do? Well, Solar thermal only works when the sun shines. When it does, the price of electricity is about .09-.14/KW. The problem is that solar thermal requires energy storage to go all night. Also you would have to build out a much larger field of collectors (the original group was collecting for the daytime). If you do storage, then the price is jacked up to .16-.25/kwh. Simply put, you can not compete with the .07-15 price. BUT, if we take CURRENT COAL plants, and add these collectors to them, there will be no need for storage. More importantly, it will lower the use of coal. Basically, you can think of the collectors doing the real work during the day time. During the day time, the collectors have the potential to replace 60-80% of coal. That is HUGE. So, why should this be used? Because we need to get manufacturing going. As you increase manufacturing, the price goes down. Today, the price of the collectors is .09-.14kw. If we push strongly on this, the price of the collectors will drop within 5-10 years so that they are below .03KW (for the west; the east will still be higher priced). That will lead to all fo the small coal plants being converted to holding storage as well.

This is the intelligent start of converting our economy to AE. Solar PV has to be one of the most foolish ideas going. In addition, Wind is cheap, but it can not work 24x7. The solar Thermal can replace coal/natural gas and with cheap cheap storage, it can replace the coal plants. The only other intelligent choice is geo-thermal power. That is coming with potter drilling success