Smart Grid

Energy Efficiency: Better Lighting? Lower Bills? BAH!

Starting now, let’s admit the folly of energy efficiency. It’s too specific and too prescriptive. Energy efficiency is a rather narrow component of overall efficiency which properly is measured in dollars per unit of output (or consumption). Other efficiency ingredients are wear and tear (depreciation), return on net assets, maintenance costs, and all manner of other things. Pick your flavor of soup if you want, but it’s the whole meal that matters.

For two years Massachusetts has been the most energy efficient state in the U.S. Utilities there have done about all the efficient lighting, weather-stripping, rebating and retrofitting they know how to do. Yet the legislature demands more. The answer may be to leave the customer and take the larger view.

The most efficient grid is a steady state grid where demand and supply stay constant and balanced. The rhythms of life prevent that perfect state, but we are well short of what we can do. Better building management, industrial scheduling and a host of behavioral changes can do much to flatten peaks and fill valleys.

Coordinated as a community, peaks in one section can fill valleys in another; a key advantage of Microgrids. Such strategies can deploy energy storage, EV charging and distributed generation as they come along. Perhaps the future of Integrated Resource Planning should include “Energy Districts”, microgrids that self optimizes and present a “flattened” profile to the larger grid. Maybe the utility of the future should develop, own and operate such microgrid resources rather than be restricted to the traditional grid.

The grid itself has a long way to go. Many operators inject more power than may be needed to be sure the last customer on the line still receives power within voltage and frequency specs. Strategically placed sensors coupled with volt-var control can reduce send out to exactly what is necessary. Utilities that have tried it are seeing 2% – 6% reductions in power, and that’s for the entire area, not just for customers participating in efficiency programs.

Dynamic line ratings can “open the pipes” dramatically. To be conservative, operators dispatch power only up to the rated capacity of the lines that carry it, a static number. However, line capacities vary with environmental conditions and often can carry much more than a static rating (always a minimum) allows. Pilots have shown improvements up to 50%, but getting that requires data and equipment that can determine micro climate and line conditions on a continuous basis. With cool and windy conditions best, this could matter in areas where delivery of wind energy is constrained by transmission.

Clearly, the US has not scratched the surface of efficiency once we get outside the thinking that it must be specific to a customer facility. What about demand response? Glad you asked.

Efficiency is environmental, but DR is management. It can shape, tune and arrange energy use to respond to a whole host of opportunities. It is maddening to hear DR defined as peak shaving. In fact, every form of generation has an analogous form of DR. The details are for another day, but the right public policy should insure that demand side assets are deployed efficiently before adding more hard iron. Dare we broach the subject of Big Data? Just wait.

My father always said to learn a tool well, but then to use the right tool for the job. With respect to efficiency in the US, so far we’ve been using hammers for everything. Enough.

2 Responses
  1. Tana Kantor

    Anyone who starts a blog with ‘Bah!’ is OK with me. Got me reading, and thought it was a very interesting, insightful article.

  2. Phil Davis

    Thanks, Tana. We do appreciate all your support for Smart Grid. Good luck with The Green Economy.