A note on efficiency

Energy Efficiency is often promoted as the solution to all of our problems. However, it is worth thinking about a bit more carefully, as this is not always the panacea it seems to be.

• Efficiency is a ratio. That means it is a comparison of how much you get of something desirable compared to the cost. When it comes to energy efficiency, this is fairly clear. Economic efficiency, on the other hand, has a lot of hidden value judgments wrapped up in it.
• When we make an efficiency gain, the benefit of that gain does not necessarily go to reduced overall consumption. For example, if my heating system becomes more energy efficient, I may make my house warmer or keep the heating on more of the time.  Alternatively I may use the money I saved on heating to drive across the country for the weekend. This is called a ‘rebound effect’, or ‘Jevons paradox’, where an efficiency gain leads to an increase in consumption.

Where do efficiency gains go? Who benefits from them? What would we need to put in place to ensure that energy efficiency gains actually go to the climate rather than to increased consumption somewhere else?