Tuesday, March 24, 2009

The electric grid, need for smartness thereof

Wired Magazine is pushing for spending money on the national electric grid. They claim the existing grid (transmission line network) is worn out, old fashioned, and hindering the progress toward a green future. Clearly more porkulus money is required to bring the system up to modern greenie standards.
They go on to rave about clever electronic boxes that monitor this and that and allow consumers to see how much juice they are using.
Actually, the transmission grid is there to keep customers lights on if/when a generator fails. The generators are connected together by transmission lines, and if one fails, power from neighboring generators flows into the affected area to keep the lights on. With a few exceptions, like the great blackout of 1965, the grid works well. The grid only needs capacity to flow enough power to support one or two downed generator plants, say 1 or 2 gigawatts.
The grid does not have capacity to route 100 gigawatts from the midwest to the east coast. Line losses grow the farther the electricity travels, and 400 miles is about as far as is practical. Losses are set by basic physics and no amount of R&D is going to lower the resistivity of aluminum or raise the voltage at which air breaks down and permits a lightening bolt to leap from wire to ground. 400 miles is enough to bring power from Niagara to New York City or from Quebec Hydro to New England. It ain't enough to ship Iowa windmill power to Boston. No amount of porkulus money will make transmission lines work over that distance.

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