Can technological progress save us from ecological destruction? If some new clean form of energy was discovered tomorrow, could it be deployed quickly enough to decarbonize the world by 2050? A study conducted by a team led by Robert Gross of Imperial College London and published in December 2018, concluded that, on average, the adoption time of the last four major power-generation technologies was 43 years. And by the end of that time, these technologies were well established, but not yet in a dominant position.

The study covers 13 major technologies, four of which are in the electricity generation sector: nuclear energy, gas turbines, photovoltaic (solar) cells and wind turbines. Here we will focus on these four, looking at their deployment in specific countries as case studies: nuclear energy in France, gas turbines in the UK,  photovoltaic cells in Germany and windmills in Denmark.

For each technology, the study first sought to determine the duration of the discovery, development and demonstration phases, and then measured the deployment and commercialization phases. This second phase raises methodological issues. When exactly can a technology be considered to be well established? In order to make meaningful comparisons of such a disparate set of conditions, the researchers agreed that the deployment phase could be said to be over when a technology had been adopted by 20% of its potential customers. (For technical details, please refer to the study.)

Despite all the talk of accelerating technology, researchers observe that its adoption pace is generally slow, ranging from 20 to 70 years. In the case of the electric generation technologies considered in the study, the average time between discovery and widespread adoption was 43 years, which makes energy a somewhat unresponsive industry. This is understandable, as they require heavy investment and facilities have a very long lifetime. Replacing one technology with another is therefore a lengthy process. Consequently, if a brand new form of energy were discovered tomorrow, we would probably have to wait until 2062 for it to reach 20% of its potential market – and a small share of the overall energy market.

The research team also notes that the adoption pace of new technologies is highly dependent on social and regulatory factors. Long periods of stagnation can be followed by accelerated deployment phases. Researchers point out, for example, that the initial adoption of cars was quick, but that there wasn’t a critical mass of people who could afford to buy one before the 1950s. The slow spread of gas turbines was partly due to European Union rules restricting this energy source in the 1970s. Finally, researchers simply cannot explain why LED bulbs fail to break through in the domestic lighting sector.

Technology adoption chart

Evolution of the four electric generation technologies

The introduction of combined cycle gas turbines was first contemplated in Switzerland in 1939. A first plant was inaugurated in the United States in 1949, then another in Luxemburg in 1956. These first tests led to an effective deployment of modern and efficient turbines from 1970 on. In Great Britain, this alternative became popular with the energy market deregulation of 1989. Deployment peaked in 2012, but the 20% adoption threshold was reached much earlier, in 1995. From 1949 to 1995, the  development and deployment phases spanned 46 years.

The first modern three-bladed wind turbine with a capacity of 200 kW was tested in Denmark in 1957. But it was not until 1979 that a first commercial windmill was deployed, with a capacity of no more than 30 kW. Denmark reached a peak wind capacity of 5.3 GW in 2017 and the 20% threshold was reached in 1997. The deployment phase spanned 40 years, from 1957 to 1997.

The origins of nuclear energy can be traced to the Maud Committee in 1941 and the efforts of the Manhattan Project to build the atomic bomb. In France, a first experimental graphite reactor was commissioned in 1956, followed by a first commercial reactor in 1959. Nuclear power peaked in 1999, with a 63 GW capacity. The 20% threshold was reached much earlier, in 1980. Deployment took 39 years, from 1941 to 1980.

The photovoltaic effect was described by Becquerel in 1839 and the photoconductivity of selenium was observed as early as 1873. However, it was not until 1954 that the first photovoltaic cell was tested in a laboratory. The Thousand Roof Project, launched in 1991, is considered the first large-scale commercial application in Germany. German photovoltaic capacity peaked in 2015 at 39 GW, and the 20% threshold was reached in 2009. That’s a deployment phase of 55 years, from 1954 to 2009.

Conclusions and policy implications

The researchers’ first observation is that once a technology is discovered, it takes at least 30 to 40 years before it is tested and deployed on a significant scale. Launched today, a massive research effort wouldn’t meet the 2050 deadline for a carbon-free economy. In addition, the initial stroke of genius is not enough: the development and demonstration phase also requires a sustained research commitment before the product can be said to be market-ready.

Researchers also note that the instant success of some recent consumer products is not a good model for predicting the deployment pace of industrial technologies, including power generation technologies. Products that can operate on existing structures (for example, cell phones or flat screen TVs) spread faster than those requiring new habits and new infrastructures.

Thus, we are essentially limited to existing technologies if we want to reverse climate change by 2050. This is an important reality check for those who subscribe to technocentric energy transition scenarios.


Gross, R. et al. “How long does innovation and marketing in the energy sectors take? Historical case studies of the timescale of invention,” Energy Policy 123, December 2018,