Erm, so, Why are there no battery's? that seems kinda like a good idea.,(reply>), +Martin Visser Pumped storage is really effective the main problem is that it shares a significant problem which is common with other hydroelectricity projects requiring large reservoirs namely that you need the right topology in relative proximity to the generators and sinks for the power you want the facility to balance. Suitable valleys to build the required dams don't always coincide nicely with the locations of major cities that consume power or for example the locations with useful renewable energy resources to harvest.,(reply>), +James Brown an alternative we have here, in Australia, are hydro electric power stations that can pump water up hill, into storage dams to consume and store energy, when it is available from power stations that are hard to turn off. they buy the power cheaply, and then they can get up to speed quickly generating power that can be sold when demand is high.,(reply>), Batteries have a number of problems: They're expensive, they require toxic or hazardous chemicals (lead or lithium), most won't last too long if they're subjected to deep charge/discharge cycles," and their energy density is pretty awful. Look here for the energy density of various batteries and fuels: <a href=""https://en.wikipedia.org/wiki/Energy_density"">https://en.wikipedia.org/wiki/Energy_density</a><br>In addition", the electric grid runs on alternating current, and batteries provide only direct current. So you have to add in a device called an inverter to convert the battery output to AC. Hope this helps.