Der Spiegel - Is Carbon Capture From Coal Generation A False Hope?

[hatrack]

EDIT

"Water and wind are already, partly, in that price bracket. Geothermal and bio-mass power will also be in that price bracket by 2020," Grünwald told SPIEGEL ONLINE. According to the TAB study, seen by SPIEGEL ONLINE, emissions-free coal power plants will have to compete against other forms of electricity production that also produce little CO2. Grünwald pointed out that CO2 capture is only economical if one has to pay to release carbon dioxide -- as is the case with carbon emissions trading schemes. The savings, he said, should lie at around €30 to €40 ($46 to $62) per ton of CO2. TAB reckons capturing the greenhouse gas will cost between €26 and €37 per ton of CO2. "This is the biggest cost," Grünwald explained, but one has to add transport and storage costs.

Despite all research attempts, CO2 capture technology still has its uncertainties. "Technologically, the whole thing is not resolved by any means," Jürgen Metzger, a chemist at the University of Oldenburg told SPIEGEL ONLINE. Speaking about underground storage, he warned: "It will have to be locked up safely; you only have to remember the latest earthquake in the Saarland" -- a February tremor in western Germany triggered by coal mining. He added that the CO2 capture technology had only been tested on a small scale so far.

Metzger also pointed out that capturing greenhouse gas takes a lot more energy, an extra 20 percent. To become environmentally friendly, power plants would therefore have to use up some of the electricity they generate, markedly reducing their efficiency. Metzger questioned whether it would even be possible to cost-effectively capture CO2: "Twenty euros per ton -- that is far too optimistic," he said. TAB's cost estimate of between €26 to €37 per ton was arrived at using calculations by several scientists.

A number of concepts have been developed in an effort to further the C02 capture idea. According to TAB, depleted oil and gas fields, as well as aquifers would be suitable as permanent storage places for carbon dioxide. So far, though, the TAB study has only been presented to a committee of the German parliament in Berlin.

EDIT

http://www.spiegel.de/international/business/0,1518,542508,00.html

[phantom power]

1. Yes. Yes, it is.

They should pay me the big bucks.

[IndyOp]

2. We don't get back down to 350 ppm wasting money & time on capturing carbon from coal -

90 square miles of solar panels in the desert southwest will power the U.S. and we need research on how to capture carbon that is already in the atmosphere to quickly move back toward 350 ppm

:grr:

[muriel_volestrangler]

4. Not '90 square miles'

Possibly 'a square, 90 miles by 90 miles'. They're different things. ">From here, the maximum solar radiation anywhere in the southwest US gets is 7 kWh/m2/day, averaged over the year. US annual electricity consumption is 3.816 trillion kWh (2005). With theoretical 100% efficient PV panels, this would mean needing 3.816 * 10^12 / (7 * 365) = 1500 million square metres. That's 1,500,000,000 / (1609 * 1609) = 577 square miles - with 100% efficiency. If you had 90 * 90 = 2700 square miles of PV panels, they'd supply that amount of energy if they were 21% efficient. That's with no allowance for transmission losses - if you really did it all in the southwest, these would be significant, sending it across the country - or losses in storing the energy for night-time use. There's also the question of electricity usage at different times of the year, and the lower amounts of solar power available during the winter to think of. Would it be practical to store the energy for months, or only a few days?

The Scientific American article linked from another thread reckons the US would need 30,000 square miles of PV arrays, reckoning an efficiency of 14%- achieved in the lab, but not yet in a commercial array.

[kristopher]

6. The storage discussed is known as CAES

Compressed air energy storage. It is mated to natural gas turbines for dramatic efficiency increases.

http://www.electricitystorage.org/tech/technologies_technologies_caes.htm

[muriel_volestrangler]

7. Though, in the long run, I'd hope for storage that doesn't involve

a fossil fuel at all.

[kristopher]

8. That's a pretty pessimistic take.

Granted we would still be producing some carbon, but look at the scale of the reduction. You aren't only increasing the efficiency of the gas plant, you are using the gas plant to stabilize a sector of wind/solar power. This enables the use of the renewable as a baselod power source, turning off coal generation.

This can enable a massive reduction in carbon emissions.

[Kolesar]

3. We will need "something" in cloudy northern latitudes where we get

Either expensive coal fired electricity with sequestration or expensive nuclear electricity.

[kristopher]

5. No, it isn't a false hope.

But it is a bad bet.

Developing and deploying carbon capture and sequestration technologies is a technological task on the order of what wind or solar was 20 years ago. The way forward should consider all the costs associated with all the choices available. If we can extract and burn coal - start to finish - that is as clean as the alternatives for less money than the alternatives then we should do it. However the existing technologies for alternatives are, when all externalities are accounted for including mercury and carbon, the better economic bet. The carbon capture technologies being thrown around are much more speculative than the dreams of solar in the 70s.
It's interesting how that role reversal is playing out.