 What is green hydrogen? So green hydrogen is hydrogen that we produce using an electrolyzer. This takes electricity in and water and it splits that water into hydrogen and oxygen gas. This hydrogen allows us to actually store the energy. We need this as we transition our energy grid over to renewables because they fluctuate over time. Not always does the wind blow or the sun shine. When we need the energy back, we take the hydrogen mix with oxygen again in a fuel cell and we generate electricity and that can be used whenever we need it.