75% renewables at midday: the record that doesn't cut your bill

75% renewables at midday: the record that doesn't ease the bill

Spain reached a milestone this midday: renewable energy covered three quarters of electricity demand. The figure, verified by Red Eléctrica (Spain's grid operator), is real, but it needs context so it doesn't become an empty slogan. It is a snapshot at the moment of peak solar generation, not the daily or yearly average. The annual average share of renewables in Spain is around 50-56%, an equally remarkable figure, but the 75% does not represent the continuous trend some are trying to sell.

The myth of imports from France

Against those who claim Spain depends on French nuclear electricity, the balances of recent years show exactly the opposite: on an annual basis, Spain is a net exporter. According to 2025 data, the net import balance was just 0.2 TWh out of total production of 285 TWh. In other words, practically irrelevant. The French dependence argument does not hold up against the figures.

Electricity prices: why renewables don't lower the bill

The big stumbling block of the current model is price formation in the wholesale market. Even though renewables produce at near-zero marginal cost, electricity is paid at the price of the most expensive technology entering the system (usually natural gas). That means the benefit of clean generation is not passed on to consumers, but pocketed by retailers. Hence, despite the record green generation, households are still paying record bills.

Added to this is the cost of past incentives –renewable subsidies– and the tax burdens borne by nuclear power, distorting the real comparison of costs. Defenders of renewables point out that, if all cross-subsidies were removed, the levelized cost (LCOE) of solar and wind is already competitive without support. But the bill for the complete system, including storage backup and fleet renewal every 25-30 years, yields a less conclusive number.

Instability: the Achilles heel of intermittency

The weak point is not generation –a proven technology– but grid stability when the sun doesn't shine or the wind doesn't blow. Without massive storage (batteries, pumped hydro) or firm backup, the system becomes vulnerable. Some engineers warn that a grid heavily dependent on renewables without that backup is the path to more frequent blackouts. The debate is not whether renewables can generate a lot of energy at certain hours, but whether they can guarantee constant supply at a reasonable cost.

The solution gaining ground is to combine renewables with storage and keep a backup fleet (nuclear or combined cycle) as insurance. But that makes the model more expensive. The future points to a necessary transition, but it will be neither cheap nor immediate. Some predict that in ten years electricity will be almost free if storage is solved; others see a decade of high costs from pending investments. The only certainty is that the debate is far from settled.