Peter Brennan

Solar, wind & batteries are beginning to do what critics claimed was impossible: Push national electricity prices DOWN at country scale. Spain may be one of the first major real-world examples of the new energy system structurally undercutting fossil-driven power markets. #SWB Their wholesale electricity market is rapidly becoming one of the clearest signals yet that the energy transition is no longer theoretical. It is now materially reshaping price formation at national scale. In Jan-Apr 2026, Spain recorded some of the lowest wholesale electricity prices in Europe at roughly €44/MWh. For comparison: • Italy: ~€127/MWh • Germany: ~€96/MWh • UK: ~€103/MWh The shift is being driven by a massive expansion of low-marginal-cost renewables. Wind + solar now supply roughly 44% of Spain’s electricity generation, while fossil generation has fallen sharply. Most importantly, gas plants reportedly set the wholesale market price in only ~9% of hours, down from ~55% in 2022. That is the real inflection point. What we appear to be witnessing is one of the first major real-world examples of electricity prices falling at country scale due to the aggressive scaling of solar, wind and batteries. Not just isolated hours. Not temporary oversupply events. But structural downward pressure on wholesale electricity markets. The old energy system depended on expensive gas generation frequently sitting at the margin and effectively dictating electricity prices across the market. But once solar and wind become large enough: • gas runs less often • peak pricing weakens • wholesale clearing prices compress • fossil volatility loses influence This is the merit-order effect now playing out at country scale. And batteries are only beginning to enter the equation. Spain’s battery storage capacity is ramping rapidly, helping absorb cheap midday solar, reduce curtailment, and increasingly shift low-cost electricity deeper into evening demand peaks. Critics long argued high renewable penetration would inevitably make electricity more expensive due to intermittency, backup requirements, and system instability. Yet Spain is increasingly demonstrating the opposite: More clean energy can structurally suppress wholesale electricity prices while reducing exposure to imported fossil fuel volatility. This does not mean the transition is “complete.” Retail electricity bills still include taxes, transmission, distribution, and policy costs. Evening price spikes still occur. Flexibility, storage and transmission expansion remain critical. But the broader signal is becoming harder to ignore: Spain may ultimately be remembered as one of the first places where the new energy system began visibly undercutting the old one economically.

Greece jumped from 8% renewables in 2000 to ~50% today. Fossils collapsed from 92% to ~53%. This isn't just transition. This is a system replacement at scale. Coal gone, gas is next. The curve isn’t gradual, it’s exponential. Cost always wins & #Bettrification in Europe surges! Zoom out and the story is simply brutal. In 2000, Greece was ~92% fossil. Renewables were just 8%, mostly hydro. Wind and solar were barely on the map. Today, renewables are hovering near 50%, driven by a surge in wind and solar over the last decade. Fossils have been cut nearly in half. That’s a 40+ point shift in a single system. Not some hippy theory. Not woke targets. Reality. Now, some will point to 2025 and say “see, renewables stalled.” They didn’t. Renewable generation actually increased. What changed was gas ramped faster, pushing its share higher and slightly diluting the percentage of wind and solar. Shares can fall while output rises. That’s what happens in a growing system. Why did gas step in? Timing. This isn’t just about how much energy is produced, it’s about when it arrives. Solar floods the grid midday. Wind fills variability. Gas plugs the gaps while the system catches up. That last ~50% fossil isn’t stubborn demand. It’s timing, storage, and system inertia. This is the messy middle. One system dying, another taking over. It's part of the journey. Coal is already gone. Gas is the temporary layer holding things together. Not the future. The delay. Next phase is obvious. Storage scales, overbuild kicks in, and gas gets squeezed the same way coal did. And zoom out again. If Greece can swing 40+ points in two decades, this isn’t unique. It’s a template.