The energy sector is the largest contributor in Europe to greenhouse gas (GHG) emissions, which are the most significant driver of climate change. To become the first climate-neutral continent by 2050, the European Commission has proposed to cut down GHG emissions to at least 50% of 1990 levels by 2030. This would only be possible with a decarbonisation of the energy sector, a transition process that is already taking place with massive installation of wind and solar power capacity across the continent.

However, renewable energy generation is weather-dependent. The balance between energy supply and demand is mostly determined by atmospheric conditions such as wind speed or temperature, which are uncertain due to natural variability and climate change. With growing amounts of wind and solar power in the electricity mix of many European countries, understanding and predicting variations of renewable energy generation becomes crucial to ensure reliable electricity systems and avoid an energy crisis.

A new study by scientists at the Earth Sciences Department of the Barcelona Supercomputing Center (BSC-CNS) shows for the first time how year-to-year changes in the atmospheric circulation patterns, known as teleconnections, impact the generation of renewable energy in different European countries. The research has special importance for the future European electricity systems as it proposes a way forward to anticipate variations in energy generation months in advance using climate predictions.

But what are teleconnections? They refer to large-scale movements of air around the Earth’s atmosphere in recurrent patterns that connect the weather conditions in regions far away from each other. In Europe, the electricity supply and demand are affected by changes in four teleconnections in the Euro-Atlantic region that can cause variations in surface temperature, precipitation, solar radiation, and wind speed: the North Atlantic Oscillation (NAO), the East Atlantic (EA), the East Atlantic/West Russia (EAWR) and the Scandinavian pattern (SCA).

“Teleconnections such as the NAO have already proven useful to the European energy sector in the past to explain episodes of low wind power generation or high energy demand. With this study, we show how seasonal predictions of the teleconnections issued months ahead can inform of upcoming risk of low renewable generation, while at the same time providing a physically consistent and simplified narrative of the episode and its consequences that can better inform decision-makers,” said Llorenç Lledó, lead researcher of the study.

Climate predictions transformed into wind and solar energy forecasts

Weather forecasts have been long used to anticipate energy generation variability from hours up to ten days ahead but beyond that, they are useless because of the chaotic nature of the atmosphere. However, new developments in the field of climate prediction make possible forecasts at longer timescales: sub-seasonal (1-4 weeks), seasonal (1-15 months), or decadal (1-10 years). These forecasts can’t precisely determine the evolution of the weather during a specific period but allow us to estimate the likelihood of experiencing above normal or below normal conditions.

The BSC study transforms seasonal forecasts of the four Euro-Atlantic teleconnections into wind and solar energy forecasts, which predict the electricity demand and the expected renewable power generation across Europe at country and regional level. The results not only show the dependence of wind and solar generation on the state of those teleconnections but also how seasonal forecasts can help decision-makers in the energy sector to better understand the supply-demand stress of the European electricity system.

Seasonal forecasts of renewable energy generation at country level can serve energy operators to schedule alternative power sources, energy traders to anticipate electricity prices, and governments to prevent electricity price crises. Also, those forecasts can be used to develop future climate services that provide and adapt climate information to specific users to support climate change adaptation.

“Beyond climate change mitigation, the energy crisis that Europe is currently experiencing as a result of the Russian invasion of Ukraine sends a clear message: our electricity system needs to move towards higher shares of renewables to achieve energy independence. And that can only be achieved with a better understanding and prediction capabilities of the weather and climate oscillations that affect the variable renewable energy sources,” concluded Lledó.

Reference: Llorenç Lledó, Jaume Ramon, Albert Soret, Francisco-Javier Doblas-Reyes. Seasonal prediction of renewable energy generation in Europe based on four teleconnection indices. Renewable Energy, Volume 186, 2022, Pages 420-430, ISSN 0960-1481.

https://doi.org/10.1016/j.renene.2021.12.130