They are likely referring to force * distance = energy. Which in context is a pitch for pumped hydro storage.
This all sounds well and good, however it’s highly unclear that utility scale pumped hydro is viable. To make it work you need to have plentiful water, limited evaporative loss/other losses, and two large basins to store both the charge, and discharge of water.
In the event of drought, these facilities could become impractical. Hydro facilities have their own environmental concerns. Combined with shifting climates and rainfall patterns there are many challenges to be solved. (some of which go away if the hydro storage is in underground ceiled chambers… which also has a cost associated)
Pumped hydro is not the only storage; otherwise I would have said E = mgh.
Pumped hydro is practical in many, many more places than have hydro generation today, because unlike those, it does not need a watershed. It can use a deep underground cavity where a hill is not forthcoming. Where water is scarce, other methods will be used.
Other applications of Fx include (but are not limited to) compressed air, and buoyancy.
Places that run low on storage resource can import and burn fuel, as they do now, or schedule power from a transmission line, where they have one. Soon, liquified anhydrous ammonia will be cheapest and most practical, but liquified hydrogen may be cheaper and sufficiently practical for bigger utilities. Ammonia has the advantage that it does not need cryogenic treatment. These will be available from numerous tropical sources.
This all sounds well and good, however it’s highly unclear that utility scale pumped hydro is viable. To make it work you need to have plentiful water, limited evaporative loss/other losses, and two large basins to store both the charge, and discharge of water.
In the event of drought, these facilities could become impractical. Hydro facilities have their own environmental concerns. Combined with shifting climates and rainfall patterns there are many challenges to be solved. (some of which go away if the hydro storage is in underground ceiled chambers… which also has a cost associated)