Efficiency gains, if not properly managed, can quietly take away most of the present market for electricity. But they also offer alert utilities an unprecedented opportunity to control risk,...
Saving Gigabucks with Negawatts (1985)
In an age of costly electricity and cheap efficiency, smart utilities will sell less electricity and more efficiency.
- reliable than building plants.
Modern Technology: Cases In Point
The savings available today are twice as big, and cost only a third as much, as those identified five years ago. (For example, Roger Sant’s pioneering 1979 least-cost analysis showed that with 1978 technologies and prices, about 43 per cent of the power sold cost more than efficiency.) Most of today’s very best electricity saving technologies were not available even a year ago. What are some of them?
- A Norelco SL-18 light bulb uses 18 watts of electricity, but produces the same amount of light as a 75-watt incandescent bulb and lasts over 13 times as long. It also gives light of better quality. Special fluorescent phosphors give nearly perfect color rendition, and a high-frequency solid-state ballast eliminates flicker and hum. If you screw one of these quadrupled-efficiency lightbulbs into a socket, replacing 75 watts with 18, you are effectively installing on the grid a 57-watt power plant, dispatching 57 “negawatts,” or unused watts, back to the utility to sell to somebody else. The SL-18 repays its high retail cost ($25 each in lots of six) two to three times over by saving $40 worth of electricity at 7 cents per kilowatt-hour, plus a dozen replacement bulbs (about $10 worth), plus the labor cost of installing them. When universally used (which should take 10 to 15 years) SL bulbs and their cousins will displace some 30 gigawatts-electric (GWe) of installed U. S. capacity at about 1 to 2 cents per kilowatt-hour. The gross value of the electricity saved will exceed $8 billion per year.
- High-frequency electronic ballasts improve the quality of fluorescent light and can save about 40 percent of their electricity, paying back in about a year. Automatic dimming by a daylight sensing photocell can increase the direct saving to 70 to 90 percent. Such ballasts, costing about 0.5 cents per kilowatt-hour, can displace 25+ GWe directly, plus 15+ GWe more by reducing air-conditioning loads.
- Daylighting retrofits, better lights, and improved mechanical systems can shift the balance point of typical deep-plan office buildings by at least 40 degrees Fahrenheit with a payback time of a year or two. (Thus a building which currently needs air conditioning at outside temperatures above, say, 20 degrees could now do without it up to 60 degrees.) Recirculation of ventilation air through floor-slab channels can also shift any residual air conditioning to the middle of the night. Even rudimentary retrofits of U.S. commercial buildings have cut electric demand by an average of 29 percent with a payback of about eight months. In the best new office buildings from Reno to Stockholm, no space conditioning is needed, yet capital cost is reduced by savings on mechanical systems. Similarly, a new office building in Jamaica’s tropical climate cuts electric use by about 90 percent at no extra capital cost. New retrofit techniques can cut most houses’ space-conditioning loads by 90 to 100 percent with paybacks generally around five to 10 years at present oil prices — less with all-electric homes.
- Straightforward design improvements can more than quadruple the efficiency of