Do You Know the Differences Between Energy Conservation and Energy Efficiency?

On this blog, we frequently use the terms “energy conservation” and “energy efficiency.” What do those terms mean, exactly? When they get used in general speech, they’re often thought to be interchangeable, but they actually refer to two separate -- albeit closely related -- concepts. Here’s a simple rundown:

What Energy Conservation Is

Energy conservation simply refers to using less energy overall. In most cases, energy conservation involves behavioral changes. So if you see that your electric company bills are getting too high, you might decide to turn up the thermostat in the summer so that your air conditioning doesn’t come on as often (AC is quite an energy hog, accounting for about 19% of residential electrical energy use in the country). Other examples of habits that support conservation are keeping the refrigerator door closed until you know what you’re planning to get out and turning off the lights when you leave the room.

What Energy Efficiency Is

Energy efficiency refers more specifically to using less energy to perform the same functions. That means that, in most cases, energy efficiency is a matter of technology. We can compare some efficiency efforts to the conservation practices mentioned above. Whereas conservation would involve turning the thermostat up, efficiency would involve installing a new AC unit that uses less power to cool to the same temperature. Whereas conservation involves keeping the fridge door closed, efficiency might involve buying a newer, more efficient refrigerator (the average fridge sold today in the U.S. actually uses 75% less energy than ones sold in 1975, despite costing 60% less and being 20% larger). And whereas conservation might include turning off the lights, efficiency would involve switching out old-fashioned incandescent bulbs for CFLs or LEDs.

How They Work Together

There’s no question that we need to get a handle on our electricity usage as a country. In 2013, we collectively used 13 times more electricity than our counterparts did in 1950. So if you’re looking for energy savings, should you care more about conservation, or efficiency? The ideal solution is actually a both/and, not an either/or; they’re two sides of the same coin. We should all be striving to use responsible amounts of energy, and changed habits and improved technology can both support that goal while also allowing us to enjoy modern conveniences. If you want to look at the overall impact of energy usage, you can also think of conservation and efficiency as being two vertices of a triangle, the third being sustainable power generation. Then we’re being smart not just about how we’re using power -- we’re also being smart about how we’re creating it in the first place.

Where have you been focusing your habits, conservation or efficiency? Discuss in the comments.