Storing the renewable energy is one of the greatest barriers to the adoption of renewable energy. Electrolysers can be used to turn excess renewable energy into hydrogen. Electrolysers use the electric current to split water into hydrogen and oxygen. The hydrogen is then stored until the wind stops blowing or when the sun is not shining. At this point, the hydrogen is used through a fuel cell, where it is combined with oxygen to create an electrochemical reaction creating electricity for your house or whatever you need the electricity for. Using hydrogen as opposed to batteries allows you to maximize on your renewable energy. There is no limit to how much hydrogen you can produce and store. To run a commercially viable power plant, you need a continuous source of fuel. For run-of-the-mill power plants, this is basically not a problem: you just keep ordering up more coal, or natural gas, or uranium isotopes. But in a cruel paradox of nature, you actually can't control the supply of solar - or wind, for that matter - despite their infinite abundance: sometimes it's cloudy, or the wind is not blowing, or it's night time and electric grids cannot function unless they are able to balance supply and demand, imbalance results in voltage fluctuations, or worse.