Sunday, April 23, 2006

 

Some Thoughts on Global Warming and CO2 Capture and Sequestration

Despite all the controversy, which in fact and in tenor largely parallels the “controversy” over evolution, global warming is no longer disputed science. In the last few years, climate scientists around the world have reached the conclusion that the major cause of the current warming is anthropogenic – caused by human activities. Greenhouse gases, including CO2, are the most likely agents of climate change.

Coal, because it is largely formed of carbon, when burned in modern power plants is a major source of CO2. Because of evidence that CO2 emissions are a major contributor to global warming, the power supply industry holds a tentative but generally accepted expectation of a legislated reduction in emissions of CO2, even if there is no consensus as to when. A reasonable expectation is that new coal plants brought on line after 2010 will require some form of reduction in CO2 emissions. The only clearly viable option for reducing CO2 emissions from coal fired power plants is capture and sequestration (CCS).

CCS is expected to add 80% to 90% to the total cost of energy from a new coal plant. This comes in four parts – a reduction in plant capacity of approximately 20%, an increase in the construction cost for the CCS plant, an increase in plant heat rate, and the actual costs of the sequestration.

The most likely method of capture is adsorption on amine molecules, and the most likely method of sequestration is in deep earth formations.

If the costs of CCS are as given above, the total cost of energy out of a new coal plant can be expected to increase as much as 50%, which is pretty much pure guesswork at this point. Until facilities are actually built and operated, all costs are guesstimates.

The thing is, Natural Gas costs will continue to increase. $50/MWh now (energy only) will increase to nearly $100 if gas goes from $6 to $12/mmBtu (likely more) giving total costs in excess of $130/MWh – probably more than new coal with CCS. New coal costs are about $1800/kW and already include SO2, NOX and Hg capture. It will take another $500/kW or so to add CCS.

Finally, adding CO2 capture and sequestration (CCS) to new coal plants is estimated to approximately double the total cost of electricity produced. That is not as terrible as it sounds - doubling means going from 4 cents/kWh to 8 cents. Or maybe 5 cents to 10 cents. The point is, the fuel component alone of electricity fueled by natural gas costs about that much now. The average cost of electricity today is already 5 or 6 cents/kWh. If we replaced the entire existing fleet of coal plants with new plant incorporating CCS would increase costs maybe a third to a half.

IOW, it is very doable.

And, IMO, very likely.

I don't know how long it will take, however, or when it will truly be undertaken as a national priority. Retrofitting is about $500/kW, about the same as the CCS addition to new plant. The real problem is s serious reduction in available capacity with CCS. You lose approximately 1/3 of total capacity to the CCS effort.

Beyond that, there are almost no coal plants built after 1987. The NEWEST coal plants in the fleet are now 20 years old, and most are far older. It is time to build new plant, with or without an oil or NG crisis.

Were we to get started NOW, significant progress could be made in less than a decade.

Jake

Comments:
Jake-
I like the way you presented your case for new coal plants, RE: costs per hour compared to gas. It all seems very logical. :-)

Yet- coal as a source of power, is available in very limited amounts. Why would we want to spend all that money to build a plant that has a very limited life?

What about wind?
 
Sea, coal is all but UNlimited in quantity here in the US. We are like the coal kings of the world, we have so much. The problem is that it is so dirty in so many ways. Cleaning it up when we burn it and then disposing of the waste effectively and safely is the key. CO2 is just another waste product for which we make provisions - or WILL make provisions.

Wind works well - but not all the time, and not always when you want. We need more types of resources than just wind, or solar, for that matter.

With clean coal plants and more use of electricity in transportation, we can make a huge difference in our consumption of the high value resources - oil and gas. Yes, it will cost more money, but as I said, not so much that our economy will crash.

We are looking at $5/gal gasoline anyway. Just how easy to swallow is THAT going to be? Here in mostly rural America, expensive transportation fuel is going to wreak havoc.

Times are changing. Oil and gas are still too cheap.

Jake
 
OK- I did a little research and the USA DOES have a 100 year supply of coal in Wyoming. That is only a 100 years though. :-) What happens after that? What is being studied now, as an alternative source of power other than fossil fuels?

We live across the harbor from a coal powered electric plant. With the right direction of wind, everybody's outdoor decks & furniature are coated with a fine layer of coal dust blown off the huge slag pile.

When the incidence of cancer rose dramatically in our town and other towns downwind of the power plant, a group of concerned citizens managed to force the power plant to agree to the EXPENSIVE refitting required to clean up production of energy. It is a small victory as the time frame to complete the changes stretches out over 7-10 years.

My point being- coal may be cheap right now for electric power being generated by all these old plants you speak about. I think your ideas on building new coal plants and revamping the old ones will take a ton of money, as you say.

I am still not convinced that it is the most economical and environmentally friendly source of power. That's why I suggested wind.

As to $5 a gallon for gas- the auto makers have know for years about rising costs of oil. WHY do they insist on continuing to build huge SUV's and do nothing about MPG efficency for trucks?
 
Wyoming alone has a 100 year supply. ALL the coal in the US is more like a 400 year supply.

But even though 400 years is a long time, it isn't forever. Are we? I don't know. Personally, I have a hard time believing in the existence of this human society 400 years from now. Perhaps I am too pessimistic.

In addition to coal, there is nuclear. I believe nuclear will once again be a viable source of electrical power.

I also think that renewables and conservation will work. I just don't think either will work well enough in the near term. We ARE addicted to cheap energy. Much will have to change before we get that addiction under control.

There are plenty of energy resources left in the ground. More than half of all the oil ever found in the US remains in the ground, unrecoverable at current price levels. But at $100 a barrel? $500? $1000? The picture looks a little different at those price levels.

Jake
 
Post a Comment



<< Home

This page is powered by Blogger. Isn't yours?