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Economic considerations for carbon reduction 4

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JoshPlumSE

Structural
Aug 15, 2008
9,738
This thread is dependent on the assumption that there is a public interest in reducing carbon emissions here in the United States. That may be a big assumption for some. But, assuming it to be true, what is the most efficient way for that to be done?

To me we spend too much time arguing across political aisles about the severity and cause of global warming. I would prefer we spend more time talking about the "economics" associated with the solutions. Maybe we're wasting public funds to support projects that are intended to make us feel better, but are not particularly cost efficient if reducing carbon emissions is our goal.

My initial thoughts on the subject are the following:
1) Solar isn't all that cost effective. Expensive per kilowatt hour produced and government funding / subsidies may be better spent elsewhere.
2) Obviously Hydro power is essentially carbon free (after building the dams). But, there are only so many locations where these can be built.
3) Nuclear power is also essentially carbon free. Perhaps we need to reconsider our country's resistance to building new power plants (and forcing existing ones to decommission).
4) Conservation (i.e. forcing people to reduce power consumption) may be an option as well, but I'm mostly ignoring it. I think there are some great ways to reduce power consumption, but they ultimately put a lot of extra cost on the end consumers.... I now pay something like $10 for a light bulb that used to cost something like ten cents. I may eventually recover the cost over time. But, that assumes my kids don't accidentally break the bulb at some point over the years it takes to offset the initial cost.
5) Coal burning power plants are the worst offenders. I've seen studies suggesting that the quickest and most efficient method to reduce carbon emissions would be to replace coal burning power plants with natural gas powered turbine generators. It's definitely NOT carbon free, but if it is a cost effective step in the right direction then why aren't we doing it?
 
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Solar is very cheap actually. Solar plus significant storage, however, is not cheap- yet- unless the storage exists for some other purpose already. An example is opportunity charging battery EVs based on price, i.e. accepting a charge that isn't really needed but provided cheaply on days that happen to be both windy and sunny. Another is batteries used to moderate power demand at EV supercharger stations- they can easily be used for peak renewables storage and possibly even with some extra cost, for grid support for emergencies or peaking etc.

Wind is cheaper still- same problem with storage though.

Nuclear can be very safe and very cheap per kWh delivered over its lifetime. The problem is capital cost especially due to an extremely long design lifetime, plus the more political than technical problems of insurance (currently under-written by the public as if that cost were free) and nuclear waste disposal. As someone who designs and builds modular chemical plants for a living, I don't think that the capex per unit of a commodity produced will DROP by numbering up rather than scaling up units to meet the required demand. Accordingly I think that the current push toward "small modular nuclear reactors" is a push toward cheaper individual projects (in the hope they might be built, whereas the larger ones AREN'T) but it will necessarily INCREASE the capex component per kWh delivered over the project life. The notion that factory fabrication/mass production will overhwelm the dis-economy of small scale is based on wooly-headed thinking. The problems of security, permitting and inspections, disposal/decommissioning etc. will also spallate if you go to thousands of small distributed nuclear plants rather than tens of larger centralized ones.

Conservation is great- and to encourage it, and to encourage all the other non-emitting technologies to be used, we need fossil carbon taxes. Anyone who is against fossil carbon emissions pricing isn't serious about addressing climate change, period. It's a necessary but insufficient measure though- it needs to be coupled with other good public policy supportive of the same objective.

 
MoltenMetal -

I'm a little skeptical. If solar really costs a lot less, then it should be taking over without any government help. Right? That's how the free market works. The lowest cost solution usually wins out. Then if the government helps subsidize it (for environmental or political reasons), it should be absolutely crushing it. But, it's not, at least not to my knowledge.

I am now looking at the Lazard investment bank's numbers for energy cost. And, according to them (at least for residential rooftop solar) the cost is at least three times the cost of natural gas combined cycle turbines. Isn't that (rooftop solar) where much of the government subsidies are going? That was my impression, at least here in California.

Also, I remember when Solar City pulled out of Nevada as soon as the state of Nevada stopped subsidizing their product. Their argument, if I recall correctly, is that it wasn't economically viable for homeowners without the government assistance.

6) I left off Wind power as I view it as a bit of a red herring. It's not a very reliable source of power in MOST areas. Therefore, it is not a viable method of meeting our nations power needs. Gosh, even for places where it is reliable, it's usually most productive at times of the day when power consumption is lower. It may be reasonably low cost, but it's not a great solution for a number of other reasons.

7) I'm not much of a fan of Al Gore's proposed solution for the carbon credits and such. But, certainly a "sin tax" against the most egregious carbon releasing forms of power makes sense. As long as that revenue is then used to drive DOWN the cost of power for other solutions.
 
I'm not much of a fan of Al Gore's proposed solution for the carbon credits and such. But, certainly a "sin tax" against the most egregious carbon releasing forms of power makes sense. As long as that revenue is then used to drive DOWN the cost of power for other solutions.

Putting a price on CO2, or other GHG, emissions is not a "sin tax". It's recognising a future cost that would otherwise be hidden. If costs are hidden, market economies do not generate efficient solutions.

Doug Jenkins
Interactive Design Services
 
Look: if you're asking what renewable sources of electricity are a) continuous and b) cheaper than burning fossils and dumping their effluent untreated into the atmosphere, the answer is only one- hydro, where it is available.

Wind and solar ARE cheaper than fuel-burning technologies- right now, no subsidies needed if the projects are sited correctly and large enough to have economy of scale- but they are intermittent and hence of less value than continuous sources of electricity. By the time you add storage they are still considerably more expensive than burning natural gas for sure- assuming you get to dump fossil CO2 into the atmosphere for free. In a $150/tonne fossil CO2 tax regime, natural gas is no longer all that cheap.
 
It's extremely hard to beat petroleum's 49 MJ/kg, both on the generation side and the storage side. Li-ion batteries come in at around 1.1 MJ/kg, so they have to last at least 100 or 200 complete discharge cycles to break even.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
I hate to say it but reduction in energy demand may well be the cheapest way to make a significant difference both short and long term. If demand is reduced then whatever method is used to supply the enrgy, you still need less of it and less capacity. Solar and wind have their place as does , gas , nuclear and hydro along with several other less well known technologies. But if we are serious about reducing carbon emmissions we also have to accepot the fact that we must reduce demand across the board.

I am not talking about replacing light bulbs with more energy efficient types and driving hybrid SUVs but rethinking our whole approach to consumption. A smaller house uses less energy to construct , operate and maintain, less to air condition , heat and light. A smaller car uses less material to build and less fuel operate (regardless of source). Most of us could afford to eat less and walk more.And so on....

However this will be a bitter pill to swallow because our whole economy is based on endless growth and ever increasing consumption.

I wonder what the Easter Islanders said when they chopped down the last tree?

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"
 
Our state (Washington) voted on an initiative to pass a carbon tax. It failed, but mostly (IMO) because there was little information available, nor written into the law, as to how the funds obtained from the tax would be spent. There will likely be some follow up of this in state congress next year.
 
Leaving aside the carbon tax issue, which raises more problems than it answers - Whatever happened to tidal power generation? At one point, it was the "next big thing". And now, it's not even discussed anymore.
GRANTED, it's also an intermittent source. However my (admittedly limited)understanding is that power can be generated off much of the tide in both directions, making it far more stable than wind or solar...
 
Sounds like a good question to post...but why ask it in the bottom of a thread on carbon reduction?
 
Sounds like a good question to post...but why ask it in the bottom of a thread on carbon reduction?

Perhaps because it's directly relevant to the question in the original post?

I'd say the main reasons we don't hear much about it are:
[ol 1]
[li]There are limited sites with sufficient tidal range to make it economic.[/li]
[li]It necessarily requires a huge initial investment in a single project with a long lead time.[/li]
[li]Environmental effects are significant.[/li]
[/ol]


Doug Jenkins
Interactive Design Services
 
It looks like I'd better do some reading on the subject. I had the impression that tidal range, while definitely a factor, wouldn't be so important as to limit placement to just a few sites.
While I can understand the cost/time/return factors would play a part, I also hadn't expected a huge environmental impact, unless talking about acres of the things. Unless you're referring to land-based installations, using channels to direct/amplify the tidal surge?
In any case, it's something interesting to look into, so I'll go do that.
 
JoshPlum:

5) Coal burning power plants are the worst offenders. I've seen studies suggesting that the quickest and most efficient method to reduce carbon emissions would be to replace coal burning power plants with natural gas powered turbine generators. It's definitely NOT carbon free, but if it is a cost effective step in the right direction then why aren't we doing it?

In the US we are. The wide availability of cheap fracked natural gas has enabled this transition to occur for immediate economic reasons alone. As a result, we have the most significant reductions of CO2 emissions over the last few years of any major country (from an admittedly high starting level).

electricity-generation-by-major-energy-source_urh6an.png
 
in my ignorance ... why does burning natural gas reduce CO2 emissions ? 'cause energy/ton CO2 emitted is greater for natural gas than other FFs ? I has assumed all FFs were the same.

I have long wondered why propane is not more widely used.

another day in paradise, or is paradise one day closer ?
 
Natural gas has the highest ratio of hydrogen to carbon of any fossil fuel -- mostly methane (CH4 at 4:1) and some ethane (C2H6 at 3:1). So the result of oxidation is more H2O and less CO2 per unit of energy. The longer the alkane "chain", the closer to a 2:1 ratio it comes.

Coal is much closer to "pure" carbon with very little hydrogen, so produces about twice the CO2 compared to natural gas per unit of energy. Combine this with the ability to use natural gas in "combined cycle" turbines that get 50-60% efficiencies in converting the thermal energy to electricity, compared to typical 35% for coal plants, and you get even greater resulting CO2 reduction. (The "supercritical" coal plants starting to come on line look to increase their thermal efficiencies to 45% or so.)

Propane's ability to compress to a liquid at ambient temperatures makes it very valuable for use where it is not feasible to pipe natural gas. It would be a waste to use it where natural gas would do.
 
Burning coal, all of the energy comes from converting C into CO2.

Burning hydrocarbons a large part of the energy comes from converting H to H20.

How far changing from coal to methane is a good idea, I'm not sure. A power plant built today is likely to be around for 40 years, so it might be more cost effective to switch to other (non-fossil fuel) sources, even if the total investment/kW was higher.

If there was a realistic price on GHG emissions, the market could sort out these things, but with so much of the cost hidden it requires subsidies and central regulation.

It does seem a bit surprising that it is the more conservative governments in the world who seem to be going for the latter route, but we just have to work within the politics as they are.

Doug Jenkins
Interactive Design Services
 
If more hydrogen results in the hydrogen bonding to oxygen instead of carbon (very simplistically), then could it be feasible to add an onboard hydrogen generator to a vehicle, and expect to see CO2 emissions drop? Or would the chemistry not pan out that way?
 
No, the stoichiometry of the chemical reaction for burning dictates what's bonded

m*CxHy + n*O2 --> s*CO + t*CO2 + u*H2O

adding hydrogen does nothing to the carbon oxidation, except possibly cranking a truckload of CO and wasting another truckload of energy. The energy you would have gained in the water fusion process is negated by the energy required to crack water to get hydrogen.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
no, but Hydrogen as a fuel is under consideration for aircraft ... probably a lead balloon. The operational problems are obvious. Hydrogen is the fuel in fuel cells which are "fabulously" expensive.

another day in paradise, or is paradise one day closer ?
 
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