Solar power has generated more energy in the US than coal for the first time, with solar supplying 12.8% of the nation's electricity in May. This milestone marks a significant shift in the US energy mix, despite federal policies aimed at boosting the coal industry. The growth of solar power is driven by its increasing cost competitiveness and declining costs, making it an attractive option for new power generation. As a result, solar has become the third-largest source of electricity in the US, behind natural gas and nuclear.