Hydrocarbon Fuel Cell (aka Bloombox)
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Mintmaster
Veteran
Solar just needs too much damn area. There are plenty of techniques to concentrate solar power with mirrors or lenses and make the panel cost a minor factor, but the area needed is so large that the mirrors alone limit how cheap it can be built. The only hope is if someone can make thin film solar dirt cheap and figure out a way to reliably mount it without needing lots of glass or aluminum, as the latter is not going to drop in cost any more.
Also, ever notice that your electric bill is around 10c/kWh while coal and nuclear plants produce it at 3c/kWh? The rest is distribution cost/profit. The distribution companies are not going to survive with lower revenue, so if people generate half their power themselves then they will charge twice as much as now to deliver the rest to you when the sun stops shining or wind stops blowing.
Mint you are forgetting/neglecting to mention there are other costs besides just the SRMC. A plant could be getting paid for spinning reserve, capacity payments, and all sorts of other stuff that is not transmission and distribution. Nukes are cheaper than coal btw if estimates of cost are to be believed. Nukes are estimated at 1.7 cents/kWh and coal is fuel cost (which varies around 119-240 cents/mmbtu) + somewhere around 1.5cents/kWh of variable maintenance cost. So you need to take into account the heat rate of the coal plant and so on. Anyway long story short nukes are cheaper in terms of short run marginal cost (SRMC) than coal. T&D costs could actually decline given proper investments. I don't think it is as cut and dried as the difference between cost and bill = T&D cost is all. But of course it is helpful when making the estimate.
SB remember PV != solar thermal.
BTW a link to fuel costs
http://www.eia.doe.gov/cneaf/electricity/cq/cq_sum.html
SB remember PV != solar thermal.
BTW a link to fuel costs
http://www.eia.doe.gov/cneaf/electricity/cq/cq_sum.html
Mintmaster
Veteran
Well, I sort of considered all that to be part of distribution, as it's all related to getting generated electricity to the customers when they need it.
I agree about nuclear. It just makes sense from so many points of view.
Wind/solar are still too expensive, and if you're going to minimize total system cost (by using every kWh of energy produced) you need over 50% of your energy to come from rapidly ramping fossil fuels (I'm not sure if coal can do this). The only way to avoid this is if you're lucky enough to have hydro storage or want to pay even more for other storage solutions, which aren't even proven.
BTW, in an earlier thread when we were discussing this you were saying that there are other reasons that we should pursue wind. What were those reasons?
http://en.wikipedia.org/wiki/The_Solar_Project
It can still be cloudy even in the desert of course, but the US has plenty of deserts. With a decent spread you could probably keep the coal plants offline most of the time.
The problem with nuclear is capital costs. You need to sink large amount of capital (around $4000/KW), wait six to ten years to see a revenue stream, then wait a further 20-30 years before your investment is amortized and you start to really make money. All while competing technologies continue to shrink costs.
Cheers
Mint I cannot remember the specific context of the wind comment. I can say that given the proper location wind is cheap. A lot cheaper than solar. It is actually cost effective compared to conventional generating technologies. There are issues with intermittency and needing backup. Coal plants in general do ramp too slowly to provide for that (as you thought), but it depends on how much wind you have. Just a small % can be dealt with easily, but if it gets too high then you need natural gas generators specifically installed to back up the wind. That makes the effective cost go up significantly. (As you mentioned if you happen to have hydro you are set, or you can use storage CAES is probably going to actually be cost effective).
So basically what I am saying is that we could get some small amount of wind say 5% and it would be cheap. As you increase the amount of wind you effectively increase it's cost.
http://www.nrel.gov/wind/systemsintegration/pdfs/2010/ela_energy_storage.pdf
That report discusses in in some good depth. Denholm does good stuff. (BTW I am in the references you can guess which one
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So basically what I am saying is that we could get some small amount of wind say 5% and it would be cheap. As you increase the amount of wind you effectively increase it's cost.
http://www.nrel.gov/wind/systemsintegration/pdfs/2010/ela_energy_storage.pdf
That report discusses in in some good depth. Denholm does good stuff. (BTW I am in the references you can guess which one
)Do you know the efficiency of CAES? All the articles I can find have the compressed air used in gas fired turbines, so fossile fuels are still being burnt.
I'd imagine energy would be lost when the air is compressed since it is adiabatically heated. Heat which is lost in the resevoir, and thus can't be recouped.
Cheers
The people studying it are always a bit jumpy when you ask them. Denholm did that himself earlier. They are working now on recovering the heat form compressing the air (like solar thermal) then you could increase the efficiency, and use less natural gas, but you stil do have fossil fuel use. (So does the topic of this thread though
)I assumed the burners in CAES were just to expand the air and that the expanded air actually drove the turbines ... presumably only a small part of the energy comes from the burners and most from the potential energy in the compressed air, so why not electric heating instead of burners?
It seems that the compressed air is replacing the traditional compressor stage in a jet/gas-turbine.
The CAES uses 0.67KWh energy in the form of compressed air, and 1.2KWh energy in the form of gas producing 1KWh electricity with a rather low (IMO) efficiency of 54%. Combined gas+steam turbines does muh better than that.
Cheers
It's just screwing around in the margins ... it's fine for absorbing peak load differences in conventional plants where it makes economic sense in the present system, but unless they can create cost-efficient generators which run just on compressed air it won't really have a future in a country which tries to go with mostly renewable electricity generation for political reasons.
If renewable electricity generation actually becomes attractive for economic reasons (ie. can generate electricity dirt cheap) it will definitely not be competitive compared to systems which don't require fuel (like liquid salt thermal storage, which can directly drive steam turbines or heat engines at decent efficiency).
If renewable electricity generation actually becomes attractive for economic reasons (ie. can generate electricity dirt cheap) it will definitely not be competitive compared to systems which don't require fuel (like liquid salt thermal storage, which can directly drive steam turbines or heat engines at decent efficiency).
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