53 thoughts on “Another Green Dream”


  1. You can imagine anything you like, but then there is reality.

    Typical thermal efficiency for electrical generators in the industry is around 33% for coal and oil-fired plants, and up to 50% for combined-cycle gas-fired plants.

    That is old tech. Most thermal power plants in use today are like two decades old. If it is a coal fired power plant it could be three decades old or more. I would be surprised if you can even get parts for them today. That is where you are getting those 50% numbers from. Try actually comparing to a modern combined cycle power plant:

    http://www.gepower.com/prod_serv/products/gas_turbines_cc/en/index.htm

    “GE’s H System – an advanced combined cycle system capable of breaking the 60 percent efficiency barrier – integrates the gas turbine, steam turbine generator and heat recovery steam generator into a seamless system.”

    People (well sane people anyway) haven’t built new oil-fired plants ever since the 1970s oil crisis. So if you find any such plant, it is probably that old. They are so expensive, they only run one if there is a massive power shortage. Most oil fired power plants were replaced by natural gas power plants in the 1990s. Today a lot of those are getting displaced by wind power. When the wind blows anyway.

    My back of napkin calculation may be over or undervalued by one percent here or there, but I was actually underestimating when I gave that efficiency number for an electric vehicle, believe it or not.

  2. “…I was actually underestimating when I gave that efficiency number for an electric vehicle, believe it or not.”

    Eh, maybe, maybe not. But, in any case, it’s a bit of an apples to oranges comparison, comparing efficiency of one fossil fuel versus another.

  3. Besides which, even a putative 8% increase in efficiency wouldn’t really do a whole lot to reduce our energy consumption, even before you get into Jevon’s paradox.

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