03041 Energy Efficient versus Energy Conservative

The cheapest energy is the energy you don’t use.

Everyone is in favor of “Energy Efficiency.” We like it and we want more of it. And in fact, we get more of it, all the time. We do more work with less energy per unit of work.

So why does total energy use continue to increase? Because energy efficient is not the same thing as energy conservative.

Energy efficiency is a measure of the amount of work you get out of a given unit of energy. All things considered, energy efficiency is a good thing, because it is better to do more work with less energy than it is to do less work with more energy.

But it’s not the same as energy conservative.

To be energy conservative is to actually conserve energy and that means using less energy.

This is a particular caution when buying appliances rated by the government’s Energy Star program.

Energy Star rates appliances within certain classes, which is a matter of size. It doesn’t rate them against some ideal of lower energy use. A particular appliance might have a great Energy Star rating — “best in its class.” However, if the class as a whole are energy hogs, that Energy Star rating doesn't say much. The Energy Star system often does not rate smaller and more efficient appliances. An Energy Star rating is not actually a statement of energy conservatism. It is only of about the energy efficiency of a particular appliance compared with others of its class.

It’s a fine thing to aim for energy efficiency. Energy conservatism is more important.