National Grid Plc asked Drax Group Plc to get two coal-fired power units ready to generate on Thursday. It’s the third time in four days that the grid operator has called on the nation’s coal-fired reserve to warm up, increasing available supply as a cold snap boosts demand and wind output drops. It has so far stopped short of actually using the plants. National Grid also asked some UK households to curb power use earlier this week during peak hours. Wind generation is set to decline in the coming days, before rising again on Jan. 29, according to a Bloomberg model. The steps taken by the grid offer a stark reminder ... (full story)