UP IN NEW YORK, Consolidated Edison has been tilting with a windmill and the windmill has just won. The state Public Service Commission has ordered Con Ed to buy any excess electricity generated by the only functioning windmill in Manhattan, a $4,000 machine that an enterprising cooperative has installed on the roof of a rehabilitated tenement. According to the New York Times, Con Ed had originally declined the hook-up offer on the ground that its 10-million-kilowatt-hour system, or a repairman, might be hurt by unexpected "surges" of power from the 2-kilowatt-hour wind machine. The PSC decided, however, that any real problems could be solved by safety switches and told Con Ed to cooperate.

So the first windmill has been added to the northeastern power grid. This doesn't mean that the answer to the energy crisis is blowing in the wind, at least not yet. The cooperative figures that if the breezes are strong, its rooftop system may produce about 20 kilowatt-hours of excess power per month, which would keep one 100-watt light bulb burning for eight and one-third days in a Con Ed excavation in a street somewhere. Meanwhile, the cooperative will be buying some of Con Ed's power to supplement the windmill's limited and somewhat errativ supply

A more jarring note in the story is that, like most modern victories for human ingenuity, this one comes at a certain price. The PSC has allowed Con Ed to charge the windmill group a special rate, which is - you guessed it - slightly more than the normal fee for small commercial customers. The surcharges, which add up to $14.60 per month, are supposed to cover the cost of special metering. The cooperative will have some offsetting economies, it's true, because it will be buying less electricity from Con Ed, and its occasional sales to the giant utility might bring in the grand sum of 46 cents per month - before taxes, that is. Even so, the economic incentive for tapping windpower is mighty small. One might even say that, while the cooperative won on principle, its hope for profit has pretty much gone with the wind. And that's something to think about - tomorrow, of course.