Your biomass numbers are quite fatally flawed as well.

Tell me how you can average 15 tons of biomass per acre on a hundred million acres?  This sounds like a hell of yield.  Maybe on the best land, but you are talking about a lot of marginal land and also western, arid land. And what forests are you willing to sacrifice to convert into energy fields?  

And 100 gallons of ethanol per ton?  What is the net yield per ton?

The wildest projections of ethanol production in this country do not come anywhere close to replacing 75% of the gas we currently use, let alone what will be needed 20 years from now if growth projections occur.  

The 85% figure quoted is 85% of the theoretical maximum ethanol yield.  In Robert Rapier's article that you quote, Iogen gives that theoretical maximum as 114 gallon per ton.  100 gallons per ton is 85% of that number, so Iogen's claimed yield of 70 gallons per ton is about 60% of that theoretical maximum, not the 6% (presumably 6% of the total input biomass) in your calculation.

My big fundamental problems with cellulosic biofuels are still topsoil depletion, water requirements and low net energy.  My other objection is that the commercial immaturity of the process means it won't be ready by the time we will probably need it, which may be within 5 to 10 years.

Yeah, I slipped a decimal place.  That's what I get for trying to do this at work, and in a hurry.

The whole thing looked strange as soon as I started to read the Guardian article.  The fact that the guy seems to love nukes was never in doubt, but there are a whole load of strawmen, strange assumptions and dogs that don't bark.

I love the factoid that if you wanted to power NY City using solar,you would need '12,000 square kilometres, about the size of Connecticut'. A quick look at the Wiki page for NY state shows that although the city itself is only about a tenth of that area, the state as a whole is 141,000 square km.  No mention of energy efficiency, or simply putting solar panels (which are becoming increasingly efficient) on roofs, or of co-generation and local power grids.  

There's also the fact that I cant think of any 'green' who supports large scale dams; but there was no mention of wave and tidal micropower.  

And windpower apparently means you cant grow crops or graze livestock near turbines, which is strange since everyone seems to do it.

How did this get through even the most basic of peer revue?

If the article has had peer review, then the peers were chosen to match Ausubel's integrity.

What stikes me about this is the fact that we long ago got sold the strawman of "Renewable Energy"
which was never more than a smokescreen to avoid categorizing energy resources
by the degree of their potential sustainability.

As supporters of "Renewables," who among Grist posters
would like to speak up for that abuse of Canis' relatives,
namely Battery Chicken Dung Power,
or for Mega-Hydro,
or for Agribusiness Biofuels ?

Isn't it time we simply disowned the term "Renewable"
before the Nuclear industry's shills make further hay by further discrediting it ?

Sustainable Energy is what I'm interested in developing.

Regards,

Bill

For once I agree with you :)  In the end the prognosticators will find that, for the right price and with enough information, many people will opt for alternative and localized forms of energy such as solar.  And for many the environment will not be the primary motivator.  As with the PC and the internet -- freedom will be a big motivator.  I don't know anyone who doesn't complain about utility companies -- and many fatacize about not having to pay them.  If they can instead force the utilities to buy their home-grown excess electricity -- well, they'd be thrilled.

"We must be the change we wish to see in the world." -- Mahatma Ghandi

Something happened with computer chips that did not happen with solar - huge government purchases, massive government development for the DOD and for the space program. Compare the money poured into the two industries, and you will see the different result explained. Mind you even with much smaller government subsidies solar cells dropped in price from $100+ per watt to $5.00+ per watt. (Higher in panels of course.) Wind managed to drop to the point where it is close in price to fossil fuels.

Barry Commoner back 1976 suggested a very simple rule to add to government purchasing. In any case where solar energy can be installed in a Federally financed project at the same cost (or a savings) over the lifetime of not using installing, it would have to be installed. That would have applied to a lot of remote outposts, chargers for naval vessel batteries, various niche applications where solar cells would have paid for themselves even then. One estimate is that this would have added 100 million in purchases of solar cells per year since 1976 - perhaps more if DOD applications had been include. Don't know if those purchases alone would have given us $1 a watt cells, but they might have.

I really wonder if the "experts" are even part of this discussion.  

One says solar is the way to go, another says no, the watt/meter yield is too low and the cost too high.  Who wants a 3lb solar panel for a 3 oz IPOD.  One person says nuclear another says no, there's not enough Uranium on Uranus to go nuclear.  One person says stop producing CO2, another says, human production only accounts for 6% of CO2 globally.  One person says hydrogen, another says how can you produce it without using more electricity than it saves you.  One person says Wind, another says what do you do if the wind stops blowing.  One person says Coal, another says it's too dirty.  One person says biomass, another says what will that do to the price of vegetables.  One says natural gas, another says, are you kidding, my gas bill has already doubled since they put in all those gas units.  One says oil, another says the Saudi's already own enough Mercedes' and it's dirty too.

Unfortunately the solutions should probably come from the Dilbert's of the world.  Not global warming scientists or, politicians serving a constituency.  And the solutions will be as cheap and dirty or as expensive and clean as you're willing to pay for.

Unless of course what we are all proposing is to stop letting economics and engineering drive this issue and start letting scientist and politicians dictate the technology, no matter the cost.  In that case, get out your wallets.  Because what engineers consider the best available technology is not what the scientist dream of, and not what the politicians want to sell to their constituents.

"And the power isn't cheap: 8.3 to 11.1 cents per kilo-watt hour."

Well, in the land of Fruits and Nuts (California), let me read you the rates on my last bill:

Baseline: 11.559 cents
101 to 130% of baseline: 13.14 cents
131 to 200% of baseline: 22.58 cents
201 to 300% of baseline: 31.30 cents

I would love to see 8.3 to 11.1 cents/KWh for my entire electric bill. Unfortunately, I am forced to pay some outrageous rates for the environmentalists that think consuming energy is bad, especially anything above cave-man levels of need.