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World's Largest Solar Array to use Stirling Engine

Posted by timothy on from the to-melt-even-the-largest-chocolate-bar dept.

An anonymous reader writes "Stirling engines are not a neglected or forgotten technology after all, according to a story at PESN. With 20 years of in-the-field fine-tuning, Stirling Energy Systems is now ready to go big -- real big. They signed a purchase agreement Tuesday with Southern California Edison (SEC), to install a 20,000 dish array that will cover 4,500 acres and will be capable of generating 500 megawatts of electricity -- more than all other U.S. solar projects combined -- making this the largest solar installation in the world. Each collector has a 37-foot-diameter array of mirrors to focus the sun's rays on the Stirling engine, which turns the heat into rotational torque for electricity generation. According to a spokesperson for SCE, this purchase will be in their commercial interest, requiring no subsidy in order to compete, implying that the efficiencies of the technology will give them an edge in the market."

1 of 720 comments (clear)

  1. No way, San Jose by Ancient_Hacker · · Score: 1, Troll
    No way the math works out on this. Let's make some very very charitable assumptions:
    • You can build a 37 foot steeerable dish for $10 grand.
    • You can borrow money for this shaky venture at 5% interest.
    • The rest of the equipment: heat collector at the focus, flexible piping, insulation, pipes, evaporators, heat sinks, pumps, working fluid, turbines, gears, cogs, lubricants, generators, buildings, staff, land all adds only $5M per 1,000 dishes, $5K per dish. { Note this requires slavery }
    • The Stirling cycle runs at 10% efficiency. { Note: most Stirling engines are about 5x less efficient that this}.
    • They make a breakthrough and develop an efficient Stiring regenerator, which is simultaneously long and short, conductive and insulating. See : www.tinaja.com/glib/muse116.pdf
    • All that stuff cleans and maintains itself at no cost.
    So one dish generates 2KW for say an average of a third of a day-- about 3000 hrs/year. That's 6 megawatt-hours. At 5 cents a KWh that's $300 a year of income. But it costs you 15K*.05 or $750 per year just to pay the interest.

    So even making wildly impossible assumptions, you can't even pay half the interest cost, much less make any headway on the principal.

    And don't mention subsidies-- that's just throwing money away, each and every year. Nobody notices the subsidy for a small pilot project. But its not politically feasible for anything on a large scale.