Finland's Hydropower Hits 15-Year Low, Nordic Reserves Running 26 TWh Below Normal
Finland produced just 7 TWh of hydropower through July, the lowest since 2011, with Nordic reserves 26 TWh below normal and a drier outlook ahead.
Finland's hydropower output through the first seven months of 2026 was the lowest since 2011. The country produced just 7 TWh by end-July, lobby group Finnish Energy reported on Monday (2026-08-17). Low rainfall and a winter with too little snow, with whatever fell melting early, left reservoir inflows well short of normal through spring and into summer.4
The deficit extends beyond Finland. Nordic hydropower reserves were running 26 TWh below normal as of late May (2026-05-21), according to Montel EQ, with the two-week weather outlook at that point drier than normal, conditions that have since carried through August. Analysts told Montel in May (2026-05-21) that a surge in EU renewables output would spur imports and limit the regional impact. But those assessments preceded the full extent of Finland's July shortfall becoming clear.2
Yet Finnish power prices have not behaved as a 15-year hydro low might imply. Finland recorded just 40 hours of negative power prices in the first half of 2026, down 88% from the same period in 2025, Montel EnAppSys data showed. Finland's Day-Ahead was trading at €12.70/MWh on Monday (2026-08-17), reflecting wind abundance rather than any shortage-driven premium.3
That drop in negative-price hours came despite the hydro deficit, not because of it. Electrification of the heating sector has absorbed supply that in earlier years was uncontested, raising demand during off-peak hours. Battery storage capacity has grown, cutting the surplus spikes that once pushed prices below zero. And the absence of surplus hydro, which in wetter years floods the grid in spring, has removed a chronic source of oversupply. Analysts attributed the shift to all three factors, Montel reported.3
Wind has become the structural offset. Finland's installed wind capacity reached 9.4 GW by end-2025, covering roughly 28% of total electricity consumption, Renewables Finland data show. The buildout is accelerating: industry participants told Montel in the week of 2026-05-18 that rising power demand from data centres and electric boilers makes further onshore investment close to inevitable, with one participant describing additional wind development as seeming "inevitable."1
That demand signal matters for grid dynamics as much as supply. More load from industrial electrification means fewer hours where generation overwhelms demand, which partly explains why negative-price hours fell so sharply in H1 even as hydro volumes dropped.1,3
Still, the region-wide reserve gap remains substantial. A 26 TWh shortfall below normal for the wider Nordic system is not easily closed through imports alone, and the drier-than-normal weather outlook through late August provides no obvious near-term reprieve. Norwegian and Swedish reservoirs hold the bulk of the region's water storage, and their recovery trajectory matters most for how tight the Nordic market runs going into winter.2
Autumn is rarely forgiving of thin hydro inventories. If dry conditions persist through August and September, the months that would normally recharge Nordic reservoirs, the balance going into peak winter demand will be worse than current prices suggest. Thermal backup and higher imports would then do more of the work, and the 40-hour negative-price count from H1 will look like a feature of a specific structural moment rather than a lasting shift.3,2