As the North Cools, the Question Flips From Cooling Peak to Heating Peak

REYKJAVÍK — All summer the grid's enemy was the air conditioner; by December it will be the heat pump, and the engineers who plan the temperate north's power are already living in that future. Fusion now carries close to a third of the reconnected grid, and the summer cooling peak — the season when the warm belt's compressors nearly broke the system — passed this year without a blackout. The relief was brief. "We spend six months terrified of the cooling peak and six months terrified of the heating peak, and the terror only changes clothes," said an Aurora Fusion Works dispatcher in Reykjavík, where the season has already turned. The heating peak is the harder problem in some ways: it arrives everywhere at once, on the coldest still nights, when there is no sun and often no wind, and only baseload holds the line. Aurora and its rivals are racing new reactors toward commissioning before the demand for warmth crests. The question flipping across the northern control rooms this week is the one that governs the whole cold half of the year: will the build-out beat the calendar? The reactors are coming. So, faster, is winter.