Negawatts? Saved Energy? Call It a Rosenfeld
Energy efficiency experts have cast around for a few years for a good way to describe exactly what they do. The concept is simple. If you replace, say, 100 watt incandescent light bulb with a 17 watt fluorescent, you've saved energy. But how to describe negative energy?
The Rosenfeld may be the solution, proposed this week in the scientific journal Environmental Research Letters. The Rosenfeld follows the a time-honored naming convention: watts, joules, and newtons are all standard energy or force measurements based on the last names of researchers. In this case, it's Arthur Rosenfeld, a long-time efficiency campaigner and scientist at the Lawrence Berkeley National Laboratory.
Unlike those other measurements, which denote modest amounts of energy, the Rosenfeld (which, if adopted, will likely become lower-case) is a whopper. The Environmental Research paper authors propose using a 500 megawatt coal plant taken offline for a year as their standard. That would make the Rosenfeld equal to 3 billion kilowatt-hours.
That hefty sum may seem a bit odd to use for a single unit. Here's what the authors had to say about the decision:
The increased focus on energy efficiency for shaping our energy future highlights the need for simple tools to help understand and explain the size of the potential resource. One technique that is commonly used in that effort is to characterize electricity savings in terms of avoided power plants, because it is easier for people to visualize a power plant than it is to understand an abstract concept like billions of kilowatt-hours...If adopted, the Rosenfeld does have one contender: the negawatt. It's pretty clear from the name that a negawatt is just one saved watt. That inversion could also be the measurement's problem. With no real life of its own, the negawatt has the air of make-believe.The Rosenfeld can best be used in rough back-of-the-envelope calculations and high-level summaries of analysis results for less technical audiences.
Who should care about either? The Rosenfeld's backers clearly have public policy in mind; you certainly wouldn't use a Rosenfeld to describe how energy-efficient your new refrigerator is. But used as a criteria of energy saved per year, it could also crop up within companies that are trying to quantify -- and tell the public about -- exactly how much they've saved.
Already, most large companies employ energy efficiency experts, sometimes as high-ranking executives. What they do, though, is not always well understood. With luck, the Rosenfeld will offer the field a new legitimacy.
[Photo via Lawrence Berkeley Lab]