<DrumBeat: October 2, 2007 The Oil Drum A Tuppence Extra?>

251 comments on Review: How Can We Outlive Our Way of Life?

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Nick on October 2, 2007 - 11:04am Permalink | Subthread | Comments top

Robert, batteries are "good enough", in PHEV's. Even lead-acid will do just fine in a PHEV: they're cheaper than gasoline when gas hits $.175/gallon. A PHEV-40 will displace 75-99% of fossil fuel usage, depending on usage pattern. That's enough for the moment, and of course battery capacity will grow as batteries get cheaper.

Professor Patzek's analysis of wind is a bit superficial. It's important to remember that a wind turbine may need 60 acres to prevent "shadowing" (interference between turbines), but the turbines don't "consume" that 60 acres. For instance, on a farm a turbine may "consume" about 1/4 acre for access roads and the turbine itself, leaving 99.5% of the land for farming. The same thing applies off-shore. The important thing is total resource (72TW average), E-ROI (40+), and cost (4-8 cents/kwh), all of which are perfectly good. So, wind is perfectly viable. Further, wind is competitive even now with natural gas, and wind can ramp up more quickly. Solar will be cost-competitive, and scale up, but it isn't quite there yet.

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mdsolar on October 2, 2007 - 12:39pm Permalink | Subthread | Parent | Comments top

Robert,

I agree with Nick that the wind value in the figure looks suspicious. The comparison should be between solar panels and plants alone since wind is sideways solar and can't be compared in the same way. Also, solar can use in places that are not going to be used for farming so the figure has a problem there as well. If we insist that solar is mainly going to be on rooftops so that the denominator is essentially zero, there is no comparison by this method. This trend to use surface area really comes from the issues with plants, but we see it coming out in nuclear industry FUD where hydro is attacked for the surface area of the resevoir without accounting for the enhansed use of land downstream owing to irrigation and flood control. We should be careful with these surface area comparisions. The comparision of the efficiency of using quantum conversion of sunlight to electricity vrs. photosyntetic carbon storage and thermal conversion is somewhat helpful but elsewhere it can be deceptive.

Chris

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Nick on October 2, 2007 - 4:22pm Permalink | Subthread | Parent | Comments top

I agree.

I think the bottom line here is that limits to available acreage are very important for plant-based fuels, and unimportant to everything else (oil, solar, wind, nuclear, etc).

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mbkennel on October 3, 2007 - 1:15am Permalink | Subthread | Parent | Comments top

Yes. It's a silly comparison, and I think even the author knows it.

The central constraint for oil production and especially photovoltaics are capital investment costs.

For PV, acres are irrelevant, we have plenty of low-value land with sunshine.

Panels and transmission lines are central.

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FuturePundit on October 3, 2007 - 1:16am Permalink | Subthread | Parent | Comments top

Wind is especially good for electric cars because a lot of car recharging can be done over a period of hours either while parked at home or parked at work. The wind just has to blow part of the time for the recharging to work.

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251 comments on Review: How Can We Outlive Our Way of Life?

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