SAVE ENERGY

Energy Efficiency: ‘On’ Is Not ‘Off’
Paul Grover, January 2007 (GreenBiz.com)

- …most people use the terms "efficiency" and "conservation" interchangeably. When we understand how they are different, solutions to our energy and environmental problems become much clearer…
- Engineers originally created the term "efficiency" to quantify machine performance. Efficiency is “the ratio of (useable) energy developed by a machine to the energy supplied it…If we put 100 units of electricity into a motor get back 60 units of motor energy to use, that motor has an efficiency of 60%.
- Energy efficiency numbers tell us which equipment delivers “more bang for the buck.”
- Energy efficient equipment must be on to produce savings and the longer it's on, the more we “save.”…If we buy a Prius hybrid, we are driving a very high efficiency vehicle. The more we drive, the more we “save” and there is no discussion of how many miles we might drive in a year. But who is more environmentally responsible, the Prius owner who drives 40,000 miles a year or the person who purposely and carefully drives a less efficient car only 10,000 miles a year?

- Energy conservation is quite different…We “conserve” by turning equipment off when it is not needed and by optimizing the operation of equipment so that is runs only when needed. The goal of energy conservation is to minimize resource use and eliminate waste…
- After we turn on a light, our concern is how efficient the bulb is…When we turn that light off, we conserve electricity whether the bulb is energy efficient or not.
- If energy efficiency is our only concern and we do not practice conservation, lights can be on night and day and, as long as the bulbs are energy efficient, we are using electricity efficiently…Efficiency without conservation can waste a lot of electricity. Of course we need both conservation and efficiency, but which comes first?

- …without conservation, resource use increases…turning things off can be surprisingly difficult…larger commercial buildings are controlled by computers called energy management systems…It takes considerable instrumentation and skill to analyze what’s on, if it’s running optimally, when it needs to be on and how to safely turn it off when not needed…already energy-efficient clients reduce their electricity use and greenhouse gas emissions (from not using the electricity) by 40%…This is good news for our environment, the changing climate, our health, and it decreases our dependence on foreign energy resources…We can save energy using both conservation and efficiency techniques, but our efficiency efforts will be undermined unless we practice “Conservation First.”