Fifteen years ago the electric utility industry, including the company I worked at, was in the middle of “deregulating”, “restructuring”, “delaminating”, whatever the trendy name of the the spasm du jour. Technical staffs were happy to let the executive floor and the lawyers deal with that chaos – they had a tough enough time keeping the lights on with shrinking budgets. Predictably, life among the cubicles generated plenty of cynicism and sarcastic humor. For example, “Undead” was the name given to recurring inquiries by the state utility commission or other agencies that had regulatory influence. Usually these inquiries originated with a recently hired staffer reviewing our rate case application, or an intervener’s testimony before the commission. Whatever the source, the “Undead” were issues that had been repeatedly asked, discussed and answered ad nauseam (ad boredom) by our utility’s technical staff to the point where a junior engineer could usually just resurrect last year’s response from the files and send it to our law department for transmittal to the appropriate state agency.
Chief among the “Undead” were inquiries regarding Conservation Voltage Reduction (CVR). It’s been known for decades that slightly reducing the voltage to induction motors (as in air conditioners, appliances, industrial applications) can often save energy without affecting performance. The down side is that if you lower the voltage a little too much, or raise it a tad too high then the motor’s efficiency goes down and you use more energy than if you’d left it at its rated voltage.
The explanation of all this is something only an electrical engineer would love (or even tolerate) so you’ll have to trust me, search Google or send me an email.
Anyway, the “Undead” question is: why not provide customers a slightly lower voltage, say 114 Volts rather than 120 Volts, and save some energy? For years the resurrected, recycled answer was usually that distribution line voltages are controlled by the substation and they get lower as you move further out along the distribution line. Lower the voltage near the substation and you get unacceptable voltages at the tail end. Raise the tail end voltages and you get unacceptable voltages nearer the substation. Oh sure, you can use capacitors along the line, switching them in or out to flatten the voltage profile but until recently there hasn’t been available technology to measure, let alone control, real-time customer voltages anyway.
Well, that limitation may be going away. With Smart Grid technologies we can monitor customer voltages, and, conceivably optimize distribution line voltage profiles for maximum CVR energy savings. How much savings? Maybe 3 percent. That's a lot - it’s over twice the energy provided by solar power installations in the U.S. And, since we’re talking demand reduction, benefits don’t rely on weather or time of day, and you don’t have to figure out how to store it.
CVR is just one example of how efficiency and conservation strategies can be enabled by Smart Grid technologies and given new life. They may not be as sexy as renewable generation resources, but in the short term they may be faster and cheaper to deploy.