The national electricity market reached a new milestone on Sunday, with solar power outstripping energy generation from coal for the first time since the market was set up two decades ago. The crossover point lasted for only a few minutes, as low demand and sunny skies on Sunday meant the contribution from coal dropped to a record low of 9,315MW just after noon, while solar provided the dominant share with 9,427MW. Dylan McConnell, a research fellow at the University of Melbourne's climate and energy college, said that for a brief moment renewable energy represented 57% of national electricity generation. "This is what I unofficially call 'record season'," McConnell said. "It's actually still pretty early in the season [to get these numbers] but in spring or the shoulder seasons you have the combination of low demand, because there's no heating or cooling, and then nice weather on the weekend. "Those factors combine, and you get these giant shares of renewable energy that generally push out coal." While McConnell said it was only "fleeting" and that "Australia was a long way from peak renewable energy", energy prices also went negative on Sunday from 8.30am through to 5pm. It means ... energy producers were paying to keep running. Unlike more nimble solar and wind producers, coal generators are particularly hurt when prices turn negative. The costs associated with shutting down and restarting coal generators are prohibitive.