The Ergosphere
Monday, August 21, 2006


There are some things that should tell you that you're going the wrong way.

Via Green Car Congress comes news that Ohio may get a $4 billion coal-to-liquids plant.  This plant will take 7 million tons/year of coal and produce 35 million barrels/year of product.

People touting CTL as the solution to our petroleum ills shouldn't take this as cause for optimism.  The US consumed almost 7.5 billion barrels of petroleum products in 2005 (20,656,000 barrels/day); this plant can produce only 0.47% of that.  It would take 214 of them to replace our petroleum usage... if we could get the coal to feed them.  The US uses roughly 1 billion tons of coal per year (mostly to make electricity), but that much CTL would require mining another 1.5 billion tons/year.  And shipping it, and disposing of the ash....

Cost is another factor.  Unless those plants get much cheaper with experience, a nation-full of them would cost somewhere north of $800 billion.  That cost has to be paid off, the coal has to be paid for (1.5 billion tons/year @ maybe $35/ton is $52.5 billion/year or $1.05 trillion over 20 years), and we'll need rail lines to transport it and landfills for the ash.  Already we're looking at a couple trillion dollars, ignoring pollution and climate impacts.  And all of that is just to feed vehicles.

The claim of coal consumption is probably low.  7 million tons/year at 25 million BTU/ton is 175 trillion BTU, but 1.47 billion gallons of fuel at 131,000 BTU/gallon (half gasoline, half diesel) is 193 trillion BTU.  Either that plant can make something for nothing, or it is going to turn more coal into less product.

That road looks bad.  Isn't there a better way to go?

Suppose we took the incentives aimed at fossil fuels and instead directed them to... batteries.

Lithium-ion batteries currently retail for about $.69/Wh.  Putting an average of 2 kWh of battery storage on new vehicles would, at US sales of ~13 million/year, require about 26 GWh of batteries per year and cost a hair over $18 billion/year; this figure could be expected to drop rapidly.  If these batteries allowed us to replace 50% of motor-fuel demand with electricity @ 300 Wh/mile, over 10 years we'd spend less than $180 billion on batteries (and much less over the next 10).  Savings would be immense; if the average new vehicle travels 15,000 miles/year and average mileage doubles from 22 to 44 MPG, after 10 years those 130 million new vehicles would be using 44 billion gallons/year less fuel.  At prices northward of $5/gallon, that would save at least $220 billion/year.  Of course, we'd need electricity to make up for it.  That would take roughly 290 billion kWh/year (about 7.5% of current US consumption), but if we got it half from wind at 4¢/kWh, 20% from nuclear at 5¢/kWh and 30% from coal at 10¢/kWh (with carbon taxes) we'd only be spending $17.6 billion/year for power.

Coal consumption would be way down.  Producing 87.8 billion kWh/year from coal in IGCC plants achieving 8400 BTU/kWH would require 737 trillion BTU, less than 30 million tons of coal per year at 25 million BTU/ton.  Compare to 1.5 BILLION tons!  The cost for coal (included in the price of power above) would be maybe $1 billion/year.  And the cost of batteries would probably fall by half within 5 years (allowing even more fuel savings for the same price), and by another 50% within the next ten.

This is how the accounting looks to me just over 10 years and assuming NO battery improvements over that time:

$400 billion in CTL plants$180 billion in batteries
750 million tons/year coal30 million tons/year coal
$26 billion/year for coal$1.05 billion/year for coal
No savings in liquid fuelRoughly 1/3 savings in liquid fuel
Roughly today's noise and pollutionRadically reduced noise and pollution

If we are looking for good investments in America's future, batteries look like our best bet.  The sign for Fischer-Tropsch is pointing down the road to ruin.

And on that note, I'm off until Friday night.  Don't have too much fun without me.

Once again, some simple math proves the idiocy of the current direction the folks directing our energy future are taking us in.

Honestly, why can't the folks in charge simply figure out that electrification of transportation will set us on the right path and alleviate a whole host of problems that other 'alternatives' simply chip away at?!

Keep the excellent analysis coming. I'm gonna link to this post from Watthead as more folks should start to think like this.
1. If there's increased demand for electricity from an electrified transportation system, the coal is simply burned in power plants instead of converted to gasoline and diesel and used directly. I don't see how this results in decreased coal consumption--whatever change that caused coal's market share to go from 50% to 30% would be the cause.
What is that change?

2. I do not see how wind can realistically provide over 30% or so of our electricity. Plus, how can a non-load-following nuclear or coal plant back up such an intermittent source? Are gas and hydro unimportant?
To clarify Stewart's concerns...

1. Consider the rough end-to-end efficiency of the two chains. Burn the coal in a power plant at 35% or so (and new technologies are poised to improve that substantially), then relatively minor losses due to transmission, storage, and use in an electric drive train. For the CTL path, convert to liquids at maybe 65% efficiency, then minor losses in transport, then run it through an ICE with maybe 20% efficiency. You end up with maybe 30% efficiency for the electric path, and something worse than 15% for the CTL. Expressed differently, the electric path only burns half as much coal to deliver a fixed amount of energy at the wheels. There are lots of details, but the bottom line won't be too far off from 2:1.

2. I believe that E-P was referring to getting half of the electricity needed for transportation from wind; using his figures, that would amount to a bit under 4% of the total electrical production, a very achievable number.
As an Ohio taxpayer, I was thrilled to see this in my morning paper. How could we do it better? Here is a suggestion:

Liquid Fuels from Nuclear Hydrogen:

Hydrogen can be produced at high efficiency (~50%) from nuclear reactors that can produce high-temperature heat, such as the liquid-fluoride thorium reactor. Typically the hydrogen is generated from water using thermochemical processes and catalysts such as sulfur and iodine. With water as the feedstock, no CO2 or greenhouse gases are released during the hydrogen generation.

My friend Charles Forsberg of the Oak Ridge National Lab sent me a paper he recently wrote on the uses of nuclear-generated hydrogen. I was especially interested in the potential uses of nuclear hydrogen to generate liquid hydrocarbon fuels from carbon feedstocks such as biomass and coal.
The nuclear hydrogen is interesting, but what if we just used that reactor to produce more electricity, instead?

In all likelyhood, that would be more efficient than using the same amount of heat to make H2, then transporting it or combining it with other sources (which would also have to be transported) to make hydrocarbon fuels.
I read your recent comments on Biofuels on FuturePundit about Brazil's biofuel usage (and posted back as simon).
I like your approach to the whole business of allowing for the logistical costs of alternative fuels.
You might be interested, but I read that world demand for lithium is currently about 70 000 tonne/year lithium carbonate equivalent. A lot of that weight has got to be carbonate, it just makes me think that Lithium batteries may not get cheaper with mass production... but I like the cut of your jib. How about smaller autos....
Hello all,

I linked to this post over at Watthead and there's more discussion there if you are interested.
One of the causes of inefficiency in CTL is the gasification process. One-step gasification has inherent entropy production that limits the yield.

One possible solution to this is chemical looping gasification. This class of processes breaks the gasification reaction down into two or more separate steps that can be conducted at different temperatures, increasing overall thermodynamic efficiency. They also may produce pure sidestreams of CO2 without the need for an air separation plant.
The chemical-looping scheme has an extra chemical step with losses (and unrecoverable energy).  I don't see how it gets higher efficiency than conventional air separation, though it might well be cheaper.
Post a Comment

<< Home
Talk largely about energy and work, but also politics and other random thoughts

Mail Engineer-Poet

(If you're mailing a question, is it already in the FAQ?)

Important links

The Reference Library

Blogchild of

Armed and Dangerous

Blogparent of


The best prospect for our energy future:
Flibe Energy

January 1990 / February 2004 / March 2004 / June 2004 / July 2004 / August 2004 / September 2004 / October 2004 / November 2004 / December 2004 / January 2005 / February 2005 / March 2005 / April 2005 / May 2005 / June 2005 / July 2005 / August 2005 / September 2005 / October 2005 / November 2005 / December 2005 / January 2006 / February 2006 / March 2006 / April 2006 / May 2006 / June 2006 / July 2006 / August 2006 / September 2006 / October 2006 / November 2006 / December 2006 / January 2007 / February 2007 / March 2007 / April 2007 / December 2007 / January 2008 / May 2008 / June 2008 / August 2008 / October 2008 / November 2008 / December 2008 / February 2009 / March 2009 / April 2009 / May 2009 / June 2009 / July 2009 / August 2009 / September 2009 / October 2009 / November 2009 / December 2009 / January 2010 / April 2010 / May 2010 / June 2010 / July 2010 / August 2010 / September 2010 / October 2010 / November 2010 / December 2010 / January 2011 / February 2011 / March 2011 / April 2011 / May 2011 / July 2011 / August 2011 / September 2011 / October 2011 / April 2013 / November 2013 / December 2013 / January 2014 / February 2014 / March 2014 / April 2014 / July 2014 / August 2014 / September 2014 / October 2014 / November 2014 / February 2015 / April 2015 / October 2015 / March 2016 / April 2016 / May 2016 / June 2016 / July 2016 / November 2016 / December 2016 / February 2017 / May 2017 / June 2017 / September 2017 / October 2017 / November 2017 / March 2018 / May 2018 / June 2018 / October 2018 / December 2018 / January 2019 / March 2019 / June 2019 / October 2019 / November 2019 / March 2020 / June 2020 / December 2020 / March 2021 / April 2021 / May 2021 / July 2021 / January 2022 / February 2022 /

Powered by Blogger

RSS feed

Visits since 2006/05/11: