The British National Grid has warned that at times this coming summer there will be more electricity being generated than needed; when demand is low, solar output is high and some inflexible power stations are hard to turn off. The answer could be to use the excess power to generate hydrogen. Electricity would be used to split water into hydrogen and oxygen, with the hydrogen functioning as a form of energy storage for renewables. The gas would later be blended in with normal gas supplies for heating purposes, sent to fuel cells to generate electricity, or used for topping up hydrogen vehicles.