It has become commonplace in recent years, also among politicians: energy efficiency is our first fuel, and: energy efficiency first [i]. The three most important things we can do to combat climate change are to save energy, save more energy, and save even more energy.

But is that still correct? By the end of last year, I was asked the question [ii]: did you change your mind about something, last year? This is my response:

Let’s be honest, saving energy has brought us a lot. In many Western countries, total energy use is barely growing or even falling. This can largely be attributed to energy efficiency improvement: the growth of our economic activity is offset by the fact that all our devices and processes are becoming increasingly efficient. What has worked particularly well is setting standards for the energy consumption of all kinds of new stuff: electric appliances, lamps, homes, cars, and electric motors. To give a striking example: a refrigerator that is bought now has an electricity consumption that is about a quarter of a comparable refrigerator at the beginning of this century. There is little to be seen on the outside of the fridge, but behind the refrigerator door, a quiet revolution has taken place. What is going less well is the improvement of existing things: think of existing buildings, and of existing industrial installations. They all have a long lifespan, from several decades to more than a century. Improvement of the existing through retrofit is possible but proceeds slowly. The pace of the energetic renovation of homes provides a striking example. The rate of renovation rarely exceeds 1% per year in most countries. That does not help to achieve a fast energy transition. The International Energy Agency (IEA) also emphasizes the lack of progress. The rate of energy efficiency improvement is not even half of what it should be to meet ambitious climate targets [iii].

I myself have always strongly emphasized the importance of energy saving from a scientific point of view. Around 1990 I was one of the first to compile a database, with an exhaustive quantitative overview of all possibilities for energy efficiency improvement, showing that the potential is enormous. And when I moved from Utrecht to Delft as a professor in 2014, in my inaugural address I focused on ‘the neglected side of the energy system’: the demand side, and emphasized the vast opportunities for energy efficiency improvement [iv].

That is why I have always wholeheartedly supported the above slogans, such as ‘energy efficiency first’. But what struck me was one of the outcomes of the latest report by the UN’s scientific climate panel, the IPCC. In the report, we have provided an exhaustive overview of all options for reducing greenhouse gas emissions in 2030. And guess what? Although all options for energy saving in buildings, transport and industry are important, wind energy, solar energy, and stopping deforestation, for example, are – each in their own right – about as important as all those energy savings together [v]. The important role of solar energy and wind energy is particularly striking. The mantra has always been: save first, then make the remaining energy more sustainable, but that logic is no longer there. This of course is related mainly to the sharply reduced costs of solar energy and wind energy. We must quickly continue scaling up those energy sources, and we certainly cannot wait for energy-efficiency-first!

Should we then stop promoting energy efficiency? I’m certainly not there. We should anyway continue to set energy efficiency standards for appliances, homes, etc., and expand and tighten those. But at the same time, we should ask ourselves whether the policies that we have been pursuing so far for existing buildings and industrial installations are effective. Everything we have done now in terms of subsidies, knowledge transfer, voluntary agreements, and carbon taxes, is good. But I think we should go a step further and also here use regulatory instruments: setting requirements for the efficiency of buildings and industrial processes. In practice, this means: for buildings, set a maximum energy consumption per square meter, and for industrial processes set a maximum for the energy consumption per tonne of product.

Photo credit: Riccardo Annendale, via Unsplash.

[i] Zie for example: “A Clean Planet for All”, Communication of the European Commission, Brussels, 28 Nov. 2018, https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:52018DC0773.

[ii] The same question was answered by 78 scientists, journalists, politicians, etc. The full collection (in Dutch) is here: https://www.beste-id.nl/jaarlijkse-vragen/waar-bent-u-anders-over-gaan-denken.

[iii] Energy Efficiency 2021, International Energy Agency, Parijs, 2021, https://iea.blob.core.windows.net/assets/9c30109f-38a7-4a0b-b159-47f00d65e5be/EnergyEfficiency2021.pdf, pag. 20.

[iv] K. Blok, De verwaarloosde kant van het energiesysteem, inaugural address Delft University of Technology,  summary in English here: https://kornelisblok.home.blog/2019/08/15/post-4/.

[v] Climate Change 2022 – Mitigation of Climate Change, Summary for Policy Makers, Intergovernmental Panel on Climate Change, Working Group III, https://www.ipcc.ch/report/ar6/wg3/downloads/report/IPCC_AR6_WGIII_SummaryForPolicymakers.pdf, p. 37-39.