The EU wants to become a net-zero emitter of greenhouse gases by 2050. And that's pretty much where the consensus stops.

A number of pathways have been proposed for reaching "climate-neutrality," but a close look reveals sizable discrepancies between them.

The EU's own new strategy for decarbonizing its energy system draws largely from European Commission projections from 2018, predicting that in 2050 more than 80 percent of the electricity supply will come from renewables and 15 percent from nuclear.

The EU's projection does not provide a breakdown of renewables technologies, but the topline 80 percent figure is roughly consistent with several other high-profile decarbonization pathways put forward by various groups. For example: 

  • The European Climate Foundation’s Roadmap 2050, published over a decade ago, forecast an annual grid supply made up of 80 percent renewables, 10 percent nuclear and 10 percent fossil fuels.
  • Shell's much-discussed Sky scenario from 2018, which charts a path to meeting the goals of the Paris Agreement, forecasts nuclear and fossil fuels each accounting for roughly 11 percent of Europe's mix in 2050.
  • WindEurope’s Breaking New Ground study, also from 2018, estimates renewables will make up 78 percent of the mix, compared to 17 percent natural gas and 5 percent nuclear power.
  • A 95 percent decarbonization pathway shared in March this year by Eurelectric, the European electricity industry union, predicted 13 percent nuclear and 6 percent fossil fuel.

But several other high-profile projections offer up strikingly divergent numbers for the approximately 7,000 terawatt-hours a year of power Europe is expected to need in 2050.

  • A 2018 study by the consultancy firm Pöyry (now renamed Afry) estimated that fossil fuels would make up roughly 5 percent of the mix and nuclear around 4 percent.
  • A "moderate" pathway advanced by SolarPower Europe and published in April 2020 forecast almost no nuclear or fossil fuel in the mix on an annual basis.

Even where there's more or less consensus on the portion of the mix that will come from renewables, there is little agreement over the breakdown of solar and wind in the mix. 

Eurelectric believes wind could make up half of Europe’s 2050 generation mix, while Shell's Sky scenario puts wind's contribution at 28 percent. The amount of generation from what is termed "other renewables," such as hydro and biomass, varies from 5 percent in SolarPower Europe’s model — a significant drop from today's contribution — to around 27 percent in WindEurope’s estimation.

The founder and chairman of development company Mainstream Renewable Power, Eddie O’Connor, believes Europe’s generation mix will ultimately tilt toward offshore wind because of the high capacity factors it could offer.

“Solar has a capacity factor of around 30 percent and offshore wind will have 50 percent,” O'Connor said in an interview. “You could have 900,000 megawatts of wind and 900,000 megawatts of solar, and you would end up with a mix of 60 percent wind and 40 percent solar.”  

Pay attention to who is doing the forecasting

One reason for the significant differences in the models is that many have been proposed by organizations with a vested interest in backing a particular generation technology.

Perhaps the most obvious example of this is the SolarPower Europe study, which in its moderate pathway gives solar a 61 percent share of the annual generation mix in 2050 — more than twice the amount of solar predicted by the forecasts advanced by the European Climate Foundation, Afry, WindEurope and Eurelectric.

Similarly, it is not surprising that Shell’s Sky scenario contains one of the highest contributions from fossil fuels of any of the models surveyed — although WindEurope’s 17 percent level for gas is the most fossil-fuel-intensive projection of all.

Green hydrogen is now WindEurope's gas of choice, said Christoph Zipf, WindEurope’s press and communications manager. “In some hard-to-abate sectors, like heavy-duty transport, we see a role for gases, namely hydrogen."

It's critical to take the interests of advocacy groups into consideration when assessing the validity of potential pathways, said Andy Bradley, director of the consultancy Delta Energy & Environment.

One common theme in many of the roadmaps is the need to connect European electricity markets so that solar produced in the southern member states can complement wind power from the north.

Bradley noted that different countries and regions will see very different technology mixes. “There will be common technologies across most markets, but there will be big differences due to local resource availability and consumption patterns, and the way they are combined to produce an optimum solution should vary according to location.”