We have been creating standards and laws for energy efficiency for decades. Appliances, for example, have an energy rating according to their consumption and even households have an energy rating. There are also some products with low energy rating that have been banned, such as incandescent bulbs.
The question is, does such energy efficiency make any difference? The logical thing would be to think so. Over the years, we use increasingly energy-efficient products and consume less. But it may not be like that. And a study has shown that it can happen.
In California there are energy efficiency regulations in homes since the 70s, they were pioneers. Its regulations make savings of up to 80% in energy consumption. However, a study prepared by Arik Levinson (in the National Bureau of Economic Research) shows that the consumption has not had any noticeable effect compared to other States that did not approve said regulations or in front of previously built homes, keeping the rest of fixed factors .
What happened? It's hard to know but there are clues. The safest thing is that if you have something more energy efficient you can use it more time. For example, if you have light bulbs that consume less, maybe you leave them on longer. If your car consumes much less, maybe you do many more kilometers or use less public transport. People react to incentives in a way that we may not expect.
Is energy efficiency therefore bad? No, but there must be other measures to reduce consumption. For example, taxes on pollution or surcharges that encourage us to take advantage of this energy efficiency to reduce our consumption.