Solar storms that produce vibrant northern lights also create an electrical current in the ground that can cause transformers — a component of traditional energy infrastructure — to overheat. Solar storms are when the sun occasionally hurls charged magnetic particles toward Earth. Northern countries are especially vulnerable to major solar storms because the Earth’s magnetic field tends to attract those particles toward its poles. “We know very well the risks for traditional power systems, but… in the future high penetration of wind power, solar and battery storage, that changes the nature of the power system,” he said. Wind and solar power are intermittent sources of energy — meaning they don’t provide a consistent, stable supply of power.