A green Europe with no energy imports

At present, Europe meets over half of its energy requirements through imports – largely in the form of fossil fuels such as oil and gas. Following the Russian invasion of Ukraine, however, it has now become clear that this dependency endangers not only the climate but also European security.

Might Europe in future be able to eliminate energy imports altogether? Could it meet its needs exclusively from its own, renewable energy sources such as wind and solar power? A new study from ETH researcher Bryn Pickering and two coauthors at TU Delft shows that this is possible. Using a modelling approach that explores alternative technology options and where they are best deployed, the study lists more than 400 cost-effective, carbon-free and self-sufficient European energy system designs.

“It turns out that there is much more flexibility in how we achieve a green, independent energy system in Europe by 2050 than we once thought,” Pickering explains. These system designs differ substantially in detail, but they all have one thing in common: they rely on a massive and rapid expansion of fluctuating renewable energy, particularly wind and solar power. The study does not include the option to top up the system with energy from stable, non-fluctuating fossil fuel sources, yet finds there to be sufficient flexibility in a raft of other technologies that convert, store and distribute energy.

An open-source energy model for Europe

To highlight the variety of options available, the researchers have developed a high-resolution model for Europe’s energy system, which they have made openly available. For different sectors and regions, this maps both demand for and supply of renewable energy produced with established and already commercially available technologies. Across an area covering 35 countries, the model consolidates fluctuating flows of power, heat, hydrogen, synthetic hydrocarbons and biofuels on an hourly basis over an entire year.

An open-source online platform lets decision-makers, industry analysts and researchers compare the many options available. To help manage fluctuating power output from wind and solar, platform users can vary their preferred system’s reliance on a range of flexible technologies and balancing mechanisms such as storage capacity, biofuels, intra-European energy distribution, and the electrification of transport and heat. “By varying these factors at will, users can visualise the complex relationships and associated trade-offs within the energy system,” says Stefan Pfenninger from TU Delft, one of the coauthors.

Visualising trade-offs

A decision to restrict the use of biofuels, for example, necessitates a complete electrification of both heating and transportation, with electric vehicles being recharged at times of the day when sufficient electricity is available.

Supposing, however, that it is only deemed feasible to electrify 50 percent of transportation, there would be a drastic increase in demand for synthetic fuels, generated from either biofuels or electrically-derived hydrogen. To cover this demand as cost-effectively as possible, synthetic fuels must then be produced primarily in countries where electricity is cheapest, such as in the UK, Ireland or Spain. This would concentrate power generation and synthetic fuel production in specific regions, meaning that a large proportion of European states would then have to import energy from elsewhere on the continent.  

Therefore, if individual countries strive to achieve energy self-sufficiency, they would do best to completely electrify transportation and establish flexible charging, such that electricity demand can be better matched to fluctuating supply.

Greater flexibility for regional scenarios

The model results also show a wide range of regional and continental options as to where renewable energy and synthetic fuels can be cost-effectively produced. In one conceivable scenario, a restriction on energy storage capacity and limited use of biofuels would require a major expansion of wind power and hydrogen production in the UK and Ireland. To distribute the produced electricity to the rest of Europe, transmission links would have to be greatly expanded.

The need for storage capacity and biofuel use could also be reduced by an expansion of solar power in southern Europe, provided that this is supplemented by wind power from elsewhere on the continent. This would mean that hydrogen production could be split between northern and southern hubs and power grid expansion could be more evenly distributed.

A better understanding of potential energy futures

The model and online platform enable researchers and decision-makers to analyse more clearly the conditions determining the creation of a green and self-sufficient energy system for Europe, along with the various options and trade-offs involved. For example, it is now easier to assess both the advantages and disadvantages of concentrating energy generation in just a few regions, compared with a more even regional distribution. 

“The basic assumptions of this model are subject to a number of uncertainties,” Pickering says. “The 441 options are illustrative views of possible futures to help make decisions now, and should not be taken as predictions.”