An article in Monday’s WSJ talks about the EPA requiring a reduction in CO2 output by fossil fuel burning power companies.
From my limited chemistry/physics, CO2 is a product of perfect combustion. It’s not a by-product (like nitrous oxide). What could they possibly do (chemistry/physics wise) to reduce CO2 output by 30% without reducing electrical output by the same 30%?
You’re asking the wrong question. While CO2 sequestration is theoretically possible, this is a long-term strategic plan that reflects the fact that fossil fuel fired power plants are the largest single source of CO2 emissions in the US, and coal plants are the worst of them all – not only contributing to massive CO2 emissions but to thousands of premature deaths every year from air pollution.
Does this sequence of pictures illustrating the future of coal power help to answer your question?
To quote this NYT article:
Short answer: “CO2 scrubbers”
You’re right, they can’t change the chemistry of burning, but they can treat the exhaust to remove the CO2.
Good response from Paul Krugman, too:
Build more nukes.
There are lots of options of doing this. I am listing them in terms of attractiveness :
1> **Go the Supercritical route **:
Pros :
[ul]
[li]Supercritical coal fired power plants are around 45% efficient compared to traditional coal fired plants which are around 33%. [/li][li]Keep running on coal which is more predictable pricewise over next 10 years[/li][/ul]
Cons:
[ul]
[li]Capital needs to be invested[/li][li]If 5 years down the road, EPA changed its mind - either going up or down on the CO2 emissions, it will be a major blow to the NPV.[/li][/ul]
2> Go Natural Gas Combined cycle:
Pros :
[ul]
[li]50% + Efficiency. [/li][li]Use cheap (for how long?) abundant shale gas[/li][/ul]
Cons:
[ul]
[li]Capital needs to be invested[/li][li]Gas prices are expected to rise.[/li][/ul]
**
3> Go for post combustion CO2 capture:**
Pros :
[ul]
[li]CO2 capture units bolt on to existing plants[/li][li]Is cheaper than converting a whole traditional plant to Supercritical[/li][/ul]
Cons:
[ul]
[li]Capital needs to be invested - Technology proven but fairly new.[/li][li]Finding a home for the captured CO2 is a nightmare. Storing underground is controversial. EOR use is very limited.[/li][li]Net Plant Output drops since a significant amount of energy is used in capturing and compressing the CO2[/li][/ul]
4a> Go for IGCC - Integrated Gasification Combined Cycle:
Pros :
[ul]
[li]Run on coal. CO2 capture happens at higher pressure and hence cheaper[/li][li]Overall efficiency 50% +. Least emissions on NOx, SOx and Mercury and solid pollutants.[/li][/ul]
Cons:
[ul]
[li]Very Capital intensive - Technology proven but fairly new.[/li][li]Finding a home for the captured CO2 is a nightmare. Storing underground is controversial. EOR use is very limited.[/li][li]Net Plant Output drops since a significant amount of energy is used in capturing and compressing the CO2[/li][/ul]
4a> Go Nuclear:
Pros :
[ul]
[li]No CO2 emissions[/li]
[/ul]
Cons:
[ul]
[li]Very Capital intensive [/li][li]Long time to permit and from permit to startup[/li][li] Perceived Safety/Environmental concerns (although these are minimal)[/li][li]Small plants not economically feasible [/li][li]Plants have low availability - that is xx days in a year,the plant is offline [/li][li]Greater need for water (thermal pollution)[/li][/ul]
While more nuclear is a good idea and should be pursued, nuclear isn’t the only carbon-neutral generating technology out there. We should also have more investment in wind, geothermal, tides, and solar. Also don’t forget about conservation: Some portion of our power production already comes from green sources (mostly hydro), and decreasing consumption would allow that to be a bigger slice of the pie.
The problem with that pro and con analysis is that it doesn’t take into account the real consequential costs of emissions – the real environmental costs of fossil fuels which should be reflected in their price, but aren’t because the atmosphere is traditionally considered to be an infinite waste dump and the costs of dumping GHGs (and myriad other pollutants) into it is implicitly assessed at zero, and the influence on global climate is likewise implicitly considered to be zero.
Without those factors, the obvious answer to electric power generation is more or less to mindlessly keep burning whatever the hell the cheapest thing is to burn. A more comprehensive approach focusing on consequences dramatically changes that cost equation.
You are definitely correct on that. A few years back carbon credits system was setup where industries were going to trade - it did not work.
The trick is to come up with a CO2 trading system that is fair and capitalism driven - otherwise we will just have more ethanol like government programs.
If I had 100 dollars and had to invest to reduce carbon emissions - I would invest more on the traditional energy sources - fossil fuels, nuclear and hydro. Together, they account for around 95% of the power produced in the US. Cite. Improving carbon emissions from these sources will give a bigger bang for the buck.
The billions of dollars spent on renewables have shown extremely poor returns. Take Spain for example - the solar market there almost collapsed when the government cut subsidies. It has made a U turn from solar energy. The wind industry has slowed down too - for example - wind energy is produced the most in the nights when demand is the lowest.
There’s a place for niche energy sources and they will always be there. If I had a limited amount of money and wanted to improve the power system - I would invest more on natural gas conversions and grid efficiency improvement (intelligent grid) and maybe storage.
Except that there’s a limit to how far the traditional sources can be improved. Hydro’s great (both cheap and environmentally-friendly, plus several other benefits), but it’s saturated: We’ve already got a dam in every good site for one. Burning any given amount of coal will always produce the same amount of carbon dioxide, and sequestration is much less practical than completely-alternative energy, so the only way you can make gains is by increasing efficiency, and there are very real thermodynamic limitations on that. And nuclear is, as I said, underutilized, but there are unfortunately some major political hurdles that need to be cleared for it.
I’m aware that solar is currently not very economical without subsidies-- There’s a reason I listed it last. But that need not always be the case, and R&D is continually bringing it closer to being economical. And wind has maybe “slowed down” in the sense that it’s not growing as fast as it used to, but it’s still growing, and there are plenty of places that get a significant amount of reliable wind day and night.
We’ve hit cost parity with unsubsidized onshore wind vs natural gas and coal. It happened this year. http://reneweconomy.com.au/2014/european-utility-says-wind-now-cheapest-form-of-generation-43032 . Solar’s next - the same study says that it only has to drop another 25% in cost - module cost’s fallen from $3.75/W to $0.90/W since 2008.
It’s all over bar the shouting and the fight to scrap over $1 trillion in capital investment. When it costs half as much to build PV installations as it does to run a combustion powerplant, area diversity and even inter-time-zone distribution will you allow you to make up for the lower capacity factor by building twice as much capacity for the same price.
Wow ! The renewable folks conveniently tell the facts in their favor and ignore the facts that there are not.
A few years back, I was leading a design team for the design of a solar plant (solar concentrators) in Europe. It worked great - except they also had to build a gas powered combined cycle plant to generate the same amount of power on days the solar plant did not not work. So the capital cost was roughly 3 times what they would need for a simple gas powered combined cycle plant !!!
We as a modern society need power that has a certain time profile and has to obey the laws of thermodynamics. So, if you look at the power consumed in the US, you will see that there is a base load, seasonal variations, and day to day variations.
Base load power plants (most coal and gas powered combined cycles) meet these needs. The power producers have to guarantee that they will produce X amount of megawatts **continuously ** , day & night, summer & winter and wind or no wind. They can only come down for certain pre-approved periods (mostly in the winters). Solar and Wind can never do this - unless power storage (the holy grail) becomes practical. Geothermal and hydro can do this but geothermal is in infancy and hydro is already saturated.
The problem that you are trying to solve with power is not just to produce it cheaply with least emissions but to ** produce it as a function of varying demand**. When you factor this part in - you start seeing the problems with solar and wind.
As far as CO2 is concerned - there are no limits thermo dynamically or otherwise. You can have a 100% CO2 capture plant running on coal.
Nothing. Your suspicions are correct. There is no way to recapture that much CO2 and sell electricity at anything like the same rate, and large power plants are pretty much at the limit of thermodynamic efficiency already.
The effect of this regulation will simply be to force coal power plants out of operation, presumably in favor of natural gas. (When you burn CH4 you get less CO2 than when you burn pure C.)
It’ll be done the way we already do it with existing power plants - have extra capacity and run transmission cables from regions with excess supply to excess demand. Nothing other than hydro can achieve “100% of peak power, 100% of the time, if necessary”. Coal baseload power plants have capacity factors between 75% and 85% per table 4-1 in WEC (some exceptional plants are in the low 90%s). Nuclear plants used to be in the 50% to 60% range but are now mostly in the 90%s, with New England able to retain a stable grid despite the Yankee Atomic Energy plants (3 of the 5 largest in the region) going as low as 25% some years.
More capacity has to be erected for wind power to do the job (http://www.windaction.org/posts/37255-u-s-average-annual-capacity-factors-by-project-and-state#.U40sRPldXis), but PV capacity factors are very consistent. They’re in the high 30s in the winter and low 60s in the summer.
http://www2.osinerg.gob.pe/procreg/tarifasbarra/ProcNov03-Abr04/pdf/pre-est-tec/vol2/7.pdf (WEC)
Except existing power plants do not all go down with the sun (Solar) or simultaneously start producing more power in the middle of the night (wind).
Yes but at the end of the day, what is in the costs vs income,
and paying for gas is one cost that it can avoid.
You are only talking about the upfront cost and not
A Manhattan Project-like push for efficient energy storage strategies, along with infrastructure and grid modernization would go a long ways in achieving the stated goal.
In the UK we now have the crazy situation where the traditional generators (mostly gas) have to be paid to keep capacity available for when the wind doesn’t blow on the heavily subsidised wind farms.
