KILOWATTS FROM CORNOBS

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IMPACT AND IMPLICATIONS

From a technical standpoint, then, the concept of using corn by-products for fuel is a viable one. But the implications of this concept could go far beyond simply providing, power for a farm or community.

To begin with, there are a variety of other ways in which the agriculturally derived gas can be put to use. Although relying on the equipment to provide base-load (minimum-generation) capacity at a municipal plant is entirely feasible (in this case, total cost per kilowatt-hour-taking capital, labor, maintenance, insurance, and fuel expenses, with cobs at $15 per ton, into account—would work out to 35¢ ... when produced by a fully amortized 1,000-KW generator derated to 800KW capacity), a more likely situation would be one in which a gasifier system is installed to fuel an existing local generator during periods when the larger regional public utility experiences high demand levels.

In this case, costs per KWH would be about one-third higher (simply because fewer KWH would be produced), but the real savings—which affect the ultimate "bottom line"—would relate to demand costs. Typically, this would work as follows: Let's assume a small municipal utility has a total generating capacity of 2,400 KW. By maintaining its equipment in working condition, such a local utility might receive a monthly demand credit of $3.00 per KW from its wholesale supplier, a large privately owned utility. (Because the municipality can't really afford to use its diesel-driven equipment, with fuel costs alone at over 10¢ per KWH, it relies on the big utility to provide power ... but that supplier, in turn, keeps the potential of the small utility in reserve—and guarantees its availability by requiring regular exercise runs—to avoid having to build extra capacity into its own generating stations to cover the demand peaks which occur seasonally at irregular intervals.)

In our example, we'll say that the wholesale contract requires the municipal utility to pay a demand charge of $ 6.00 per KW, plus the normal fee for power. This demand charge typically applies to 85% of any new 15-minute peak for a period of six months... or until a greater peak is reached. So if, say, the small utility reaches a quarter-hour-long peak that's 100 KW above its previous highest demand level (as a result of an unusually hot summer day or the unplanned use of a grain elevator), it pays a demand charge, for that month, of 100 X $6.00, or $600. Then, for each of the next five months, it must pay 85% of that established peak, which amounts to $2,550. In short, that single 15-minute power draw cost the community a total of $3,150.

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