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> Perhaps I'm misunderstanding your phrasing, but the vast majority of the CO2 released from natural gas comes from its combustion in its end use case, not inci

> Perhaps I'm misunderstanding your phrasing, but the vast majority of the CO2 released from natural gas comes from its combustion in its end use case, not incidental CO2 released during extraction from a particular field. The vast majority of methane is burned in power plants. The CO2 can be captured at the stack, and pumped into the ground. If one million m3 of methane is burned, exactly one million m3 of CO2 is produced, not more, not less. It does not take a lot of energy to capture the CO2 from the smoke at the power plant. It may take a lot to capture it from the air, where it's very diffuse, but the smoke at the power plant is just CO2, N2 and water vapor. The N2 can be taken out of the equation by oxy-fuel combustion [1]. Adding carbon sequestration to a power plant is expensive, so one wouldn't do it without some carbon tax incentives. But it's not exorbitant. To be specific, the EIA did a study on the capital cost of various power sources [2], and here's their results: - coal without sequestration: $3700/kW; with sequestration $5900/kW - nat gas without sequestration: $1000/kW; with sequestration $2500/kW - wind: onshore $1300/kW, offshore $4400/kW - solar with 4h battery storage: $1800/kW Coal seems to be out of contention, no matter what subsidies you add. But natural gas power plants with sequestration are not that bad. The price of solar and wind is obviously contingent on location. Solar is not going to be very competitive in Maine, for example. So natural gas with sequestration at $2500/kW is definitely an option vs solar at $1800/kW if the location is not California, Arizona or Texas. But why would anyone consider this as of now, if they can just do it for $1000/kW? If the government changes the incentives though, I don't see why large scale carbon sequestration would not be viable. [1] https://en.wikipedia.org/wiki/Oxy-fuel_combustion_process https://en.wikipedia.org/wiki/Oxy-fuel_combustion_process [2] https://www.eia.gov/analysis/studies/powerplants/capitalcost/pdf/capital_cost_AEO2020.pdf https://www.eia.gov/analysis/studies/powerplants/capitalcost...

danans 3y ago
> To be specific, the EIA did a study on the capital cost of various power sources [2], and here's their results: That is just the capital costs, not the operational (fuel) costs, which are significant for natural gas plants and insignificant for zero carbon sources. The full costs are expressed by LCOE. > If the government changes the incentives though, I don't see why large scale carbon sequestration would not be viable. A tax on greenhouse gas emissions would incentivize carbon free sources of electricity like renewables, storage and nuclear just as much if not more than CCS, because CCS has a max capture rate of 90% so there is a nearly 10% disadvantage out the gate. The only way CCS wins is if its levelized cost for firm energy is lower than all the zero carbon alternatives, regardless of a carbon tax. It might be economical for natural gas powered peaker plants, which fill in supply gaps and sell power at very high prices. However, these run for very short periods so therefore the technology has to be relatively cheap up front in order for the economics to work out.

danans 3y ago

> To be specific, the EIA did a study on the capital cost of various power sources [2], and here's their results: That is just the capital costs, not the operational (fuel) costs, which are significant for natural gas plants and insignificant for zero carbon sources. The full costs are expressed by LCOE. > If the government changes the incentives though, I don't see why large scale carbon sequestration would not be viable. A tax on greenhouse gas emissions would incentivize carbon free sources of electricity like renewables, storage and nuclear just as much if not more than CCS, because CCS has a max capture rate of 90% so there is a nearly 10% disadvantage out the gate. The only way CCS wins is if its levelized cost for firm energy is lower than all the zero carbon alternatives, regardless of a carbon tax. It might be economical for natural gas powered peaker plants, which fill in supply gaps and sell power at very high prices. However, these run for very short periods so therefore the technology has to be relatively cheap up front in order for the economics to work out.