Summer is often considered a paradox season for the energy sector. On one hand, the surge in renewable energy production has set historical records, particularly in the European Union . June marked the highest production of solar energy ever recorded, generating an impressive 45 terawatt-hours (TWh), which is 22% more than the previous year. However, on the flip side, many Europeans have experienced electricity costs that have doubled or even tripled. The pressing question is: if we’re swimming in solar energy, why are we paying more for electricity?
The demand is triggered. Heat waves sweeping across Europe have seen temperatures soar to nearly 40 ºC in various regions, including Spain , France , and Germany . With air conditioning systems operating at full capacity, electrical demand has surged dramatically.
According to the latest Ember report, daily electricity demand surged by 14% in Spain , 9% in France , and 6% in Germany throughout June. This increased demand alone pressures electricity prices upwards. However, the heat wave also introduced a second issue related to supply.
Thermal plants are suffocated. The very heat driving the demand for cooling also affects traditional energy plants, particularly nuclear facilities. These plants require significant amounts of river water for cooling. When water temperatures rise, their cooling efficiency decreases, which can force them to reduce or even halt production.
France has been severely impacted . Its nuclear fleet—central to the European interconnected network—is facing capacity reductions across nearly all facilities. The issue doesn’t stop with nuclear energy. In Poland , coal-fired plants are experiencing cooling challenges, while in Italy , overheated grid cables were likely responsible for the blackout on July 1. Thus, critical energy generation is unavailable at the very moment it is most needed.
Missing storage for solar. Amid this crisis, photovoltaic solar energy emerges as a saving grace. In Germany, solar power peaked at 50 GW , satisfying between 33% and 39% of the nation’s electricity requirements. With a marginal cost near zero , solar panels effectively provide stable network support during daylight hours, even if performance diminishes during extreme heat.
However, nighttime presents a different challenge. As the sun sets, solar production drops to zero , but cooling demands remain high. When elevated temperatures persist into the night, the lack of adequate storage—whether in batteries or pumped hydroelectric systems —forces reliance on gas plants and other fossil sources, driving prices up.
The daunting “Spread”. This temporal mismatch between abundant renewable energy and the dearth of storage solutions creates price volatility . This leads to staggering daily price differentials (the “spread”) of up to €400/MWh in Germany and €470/MWh in Poland.
It’s this night peak—rather than the average price—that escalates final electricity bills, causing prices to spike even when cheap energy is available during the day. The lesson is profound: the challenge lies not only in producing low-cost renewable energy but in managing it effectively. Increased storage capacity is essential for purchasing energy at lower prices during the day and selling it at higher prices in the evening.
Furthermore, enhancing European interconnections is crucial. The heat wave did not equally affect the entire continent on the same day. For example, the highest demand peaks emerged in Madrid on Sunday, Paris on Tuesday, and Berlin on Wednesday. Strengthening interconnections would allow for better distribution of affordable energy across regions.
In summary, while the shift towards renewable energy has reached remarkable milestones, managing demand and supply effectively poses significant challenges. As Europe navigates through this energy transition, investments in storage solutions and interconnections will be vital in stabilizing prices and ensuring that the benefits of renewable sources are realized.