I assume you are referring to amine-based CO2 scrubbing?

It's a very inefficient process in a conventional PC plant-- because the CO2 stream is so dilute.

Costs are high.

Table 3.7

http://arch.rivm.nl/env/int/ipcc/pages_media/SRCCS-final/SRCCS_Chapter3.pdf

In practice, retrofitting is messy and impossible on some plants.

Willi Broecker has recently been promoting a scheme to draw down atmospheric CO2 with huge fans, for sequestration. This strikes me as completely ludicrous compared to tapping the non-dilute stream from a power plant.

I will give you one that essentially requires no energy. Shell fish farms. Assume 1000 tons of oysters a year and the weight of meat is 20 percent. It works out to about 350 tons of CO2 a year. Yes, trivial I know.

Scrubbing the atmosphere of CO2 rather than individual exhaust streams will not be an efficient solution today unfortunately. The key issue is concentration. Scrubbing processes work more efficiently with higher concentrations to remove.

The atmosphere has ~400ppm CO2
Fossil power stations emit 5-10% CO2 in the stack

The amount of energy required to remove CO2 from air would be huge, with very very low efficiencies in comparison to doing the same on a more concetrated stream.

The power generation efficiency loss from installing CO2 capture / storage on a gas-fired power plant is circa 10-15%. Assume that coal is roughly the same. ie. A CCGT will fall from 55% to 45%, coal from 40% to perhaps 30%. Cost of the equipment for capture and storage is also high, and combined with the energy used to power the capture process could potentially add 50% or more to today's electricity price.

I think a big question here is the general population's willingness to pay for this. Everyone who uses energy will have to pay in the end. Currently there are few other solutions which can be deployed - lets face it man is not going to give up fossil fuel in 10 or 20 years, so CCS will have a vital bridging role to play in managing CO2 before cleaner energy sources start to become dominant.

I'd have to dig through the IPCC report, but my understanding is that full extraction and sequestration costs you something like 25% of energy produced *depending* upon how far you have to pump the CO2 to sequester it.

In practice, from an economy-wide perspective, dealing with the CO2 from coal plants is likely to be about the cheapest form of industrial abatement (although preserving rainforest, collecting methane off garbage dumps and pig farms, etc., will be even cheaper).

"Regulate the amount of wattage in advertising signs. If everbodies ox is gored equally, no one should be disadvantaged"

But, every user of energy should not be treated equally. Those whose electricity is wasteful or is not essential to the safety and well being of the population must be charged a higher rate. The billboard companies could be charged a high enough rate to encourage them to get a solar array and battery system to light their signs. And, reduce highway lighting and airport lighting.

The auto/airline industries are huge users of electric power for lighting compared to railroads/transit systems. If more travel could be shifted to these more energy efficient modes, much electrical power could be saved. You don't see many railroad tracks illuminated at night, and the station facilities for transit and intercity passenger rail systems cover much smaller land areas than highways and airports, thus less lighting/power needed.

hi Jerome, can you tell me - are the numbers you quote just investment costs or lifecycle generation costs (investment, operational costs and fuel costs?).

Interested as want to use in a comparison for CCS I am looking at.

Fair enough.

The French cost of nuclear is lower than the Anglo-Saxon cost of nuclear.

I take any 'estimate' of nuclear power cost from the Anglo-Saxon proponents, and add at least 50%. (in practice, the actual outcomes were 400-500% higher but I'm hoping we have learned something from the disasters of the 1980s). In an Anglo-Saxon country, there is a greater dispersion of political and social power, and therefore a far greater planning and appeals process, and more political constraints on the economics.

The UK has one of the oldest civilian nuclear power industries. The estimated costs of disposal and decontamination (present value) for the industry are now £70bn-- that's got to be at least 1p /kwhr (ie nearly 2 cents) for every kwhr the industry has generated.

The grave danger of nuclear power is that it will suck up all the available government funds for alternative energy and R&D: this has apparently happened in Finland.

gas fired I am willing to be led. My understanding was at $4/mcf, that gas was competitive with coal. High interest rates in the 90s meant that gas was superior in cost to coal (60% of the lifecycle cost of a gas plant is fuel). Interest rates have fallen a lot since then (raising the relative attractions of wind, nuclear and coal).

Offshore wind is a bit unproven of course. We haven't, AFAIK, tested an offshore wind platform in a really big hurricane of the Katrina type.

The other problem with wind is that one needs gas-fired as a backup. That can really eff up the system-wide economics.

Notwithstanding, I am a big bull of wind where the geography justifies it (roughly: north western Europe, the Great Plains of the US, and offshore in many many places). I think we could profitably give foreign aid to places like Morocco and Egypt by helping them build wind capacity, which would displace diesel fuel and gas.