Ender:

Sorry I don't have access to excel right now. "If you add in coal to liquids to replace oil depletion then half the trillion tons will be gone in 2046" What happens when you plug in the estimated resource of 7 trillion tons? The .5% after 2100 would be the result of a move to much better alternatives by then. (I immagine that would happen much earlier than 2100)

Hampden:

Two things: 1) The proviso on coal is that you would have to use it cleanly (e.g. FutureGen) 2) I believe that by the middle of this century (hopefully sooner) we'll be using much more renewables such as wind (competative now) and wave, solar building materials (availible now), fussion power (ITER completes 2016) and EVs/PHEVs that are way more efficient than CTL. Coal is just a bridge.

We cannot affort to use coal as a bridge. We cannot even afford to burn the amount of coal we are using now. If you make it a bridge, it will be a mighty long one because we do not have the political will to get off coal once it is firmly entrenched.

Get off coal now. If anyone wants to use more coal, this should only be permitted if they have a viable sequestration plan in place --- now, not in 30 years.

We are burning now as we set new heat records every damn year. How can we affort to go on like this with a damn coal bridge.

Let's just say, for the sake of argument, that a truly effective anti global warming plan would damage the economy. The economy can be repaired; the planet can't, at least in period of time approaching a human time scale.

The economies of the world were devastated because of WWII. But the U.S. and the world emerged from that catastrophe stronger than ever. We need to fight GW on a scale approaching that war.

Of course, it is quite possible that the damage we have done and will do is already irreversible. In which case, excuuuuuuse me. Continue to party, as usual.

From On the Way to a Sustainable Energy Future by Ulf Bossel, former manager of ABB fuel cell development:

"A hydrogen economy involves more stages than the two obvious conversion processes of electrolyzer and fuel cell. [...] Because of the physical properties of hydrogen, all these stages require much more energy than is needed for the distribution of liquid fuels to consumers. [...] These processes cannot be made much more efficient by additional research and development.
The main losses reflect the physics of hydrogen. Only a small fraction of the original renewable electricity can be recovered by consumers with efficient hydrogen fuel cells."

t: I agree completely. No new coal should be used unless the CO2 is sequestered ... now. Some projects are under way for CO2 sequestration. The technology exists. It must be made mandatory now.

Neil - "Sorry I don't have access to excel right now. "If you add in coal to liquids to replace oil depletion then half the trillion tons will be gone in 2046" What happens when you plug in the estimated resource of 7 trillion tons? The .5% after 2100 would be the result of a move to much better alternatives by then. (I immagine that would happen much earlier than 2100)"

I put a copy in Open Office format if you don't have excel. 7 trillion tons is a VERY optimistic estimate. We have explored extensively for coal and most large deposits are well mapped. Recoverable coal reserves may not be any where near 7 trillion tons.

If you extend the recoverable reserves to 7 trillion tons Peak Coal occurs about 2090 with a growth rate of coal of 2%. Plug in 5% and it is about 2075. Mind you the consquences of burning this much coal is an increase of 5 times the present estimated amount of CO2.

Nobody is going to move off coal without some incentive. Coal is cheap and everyone thinks that we have 400 years worth of it. When you actually do the numbers realising exponential growth the coal reserves are really small and the consequences of burning it are great. Sequestration will not work - how do you propose to sequester the 100 000 million tons of CO2 that would be required at Peak Coal with 7 trillion ton reserves?

Ender, thank you for the numbers, I think that our experiences with peak oil will give us a very clear picture of what will happen when other fossil fuel resources deplete. I particularly enjoyed Ulf Bossels article. It's nice to see some optimism for a change. People will use coal as long as its economical to use it... that's where carbon taxes come in. I'll see if I can find some numbers on the total availible space for carbon sequestering (I'm not in favour of deep sea storage at this juncture). One of the down sides (or up sides depending on your thoughts) to carbon sequestering is that it extends the amount of oil that we will produce.

Does anyone have effeciency numbers on direct solar to hydrogen creation. Sorry, I can't remember the name of that particular kind of panel off the top of my head.

The bottom line is how fast can we get solar to the point where it is cheap enough to compete in the abscence of carbon taxes.

Got the numbers. Depleted oil reservoirs have only enough room for 300 to 600 GtC. The other possibility being investigated is deep (>800 meters) saline aquifers. Initial estimates of capacity is 3,000 to 10,000 GtC. Canada and the U.S. already have over 3,000 Km of CO2 pipelines. Carbon sequestration is already in use. A plant in North Dakota has been storing CO2 in old wells in Saskatchewan since 2000. The coal industry has absolutely no excuse for building new plants that don't store their CO2.

Neil - The US generated 2,014,173 GWhrs last year from coal. Burning coal releases about 900t of CO2 per GWhr so you would need to capture, transport and store 900 X 2 014 173 = 1 812 755 700 tons of CO2 per year. That is 1.8 Gtons per year. This would increase at 2% per year so in 35 years it would be 3.6Gtons and so on.

This is a lot of carbon to find holes for. Really it is much better not to generate the carbon in the first place.

http://www.eia.doe.gov/cneaf/electricity/epm/table1_1.html

Agreed - and the sooner we can get solar and fusion ready for prime the better. In the mean time its wind and coal (and we had better use that as cleanly as possible)

CS1992 + Paul:

More and more people consider that EVs will be the final solution for cars, VUS and many other person movers.

However, abrupt changes can be disruptive and should be avoided. We have to accept progressive change overs and reasonable time (15 years) to introduce each technology + higher performance Electricity Storage Devices (ESD):

A step by step approach would indicate:

1) Hybrids (1998-2013) with 1.5 Kwh ESD
2) PHEVs (2008 - 2023) with 10-30 Kwh ESD
3) EVs (2018 - 2033) with 30-90 Kwh ESD

It is obvious that the availability of affordable, quick charge, long lasting ESDs is one of the main factor slowing the arrival of PHEVs and EVs. Another main factor is the long turn around time (15 to 18 years) for people movers. To go from ICE to EVs will take 30 to 36 years.

Hydrogen Fuel Cells may be OK for niche applications such as fork-lifts, trucks, buses but are too cumbersome and complicated for everybody's cars where PHEVs and EVs make much more sense.