Energy can be stored as electricity... or thermally (most of our electricity is used to create heat or cold, that we can cheaply store for days and even months)

Energy can be stored as electricity... or thermally (most of our electricity is used to create heat or cold, that we can cheaply store for days and even months) Reversible damns are for small amount of energy and short term... but most classical damns do store much more energy - that is an energy you can decide to use now, or in two weeks, or sometime in few months. They store energy, just can't store already produced electricity Energy efficiency and demand-response have HUGE potential to reduce energy consumption, and to make energy consumption "programmable" A good mix of different renewable energy (hydro, biomass, onshore wind, off-shore wind, solar) make it impossible to have a "no wind, no sun" case, even if there will be fluctuation in what level of electricity you can produce