However a more general formula would be the integral of net force over distance.
Even without local "freshman" classes, you may look it up in any dictionary. Or, just stop pretending.
F may be water pressure, as in pumped hydro (which is growing) using elevated or underground reservoirs, or air pressure, as in CAES underground or underwater compressed air, or buoyancy using sea-floor pulleys and floats. No doubt as a soon-to-be Licensed Professional Engineer you will soon be able to think of other persistent forces.
Springs and flywheels will not be used for bulk utility-scale storage.
Generally, utilities will use what is cheap and reliable at the time they build it. Building storage before you have enough spare renewable capacity to charge it would be a bad misallocation of capital
Anhydrous ammonia will not be the cheapest medium, but has advantages of transportability and fantastic usefulness. Any unused overbuilt capacity will be put to work synthesizing for sale.
I may, but I live in a country that doesn't use the word freshman, so I don't know which year physics text that would be.
I assume from context you were meaning to refer to gravitational potential energy, which is generally represented as ∆U=mg∆h (change in gravitational potential energy equals mass times gravity times change in height). The variables you used (E=Fx) would mean energy equals force times (variable). From dimensional analysis the variable would have to be units of length (m), however it clearly only applies in the vertical dimension so it's better to use a specific variable like ∆h
Regardless, energy storage via gravitational potential energy (i.e. pumped storage) has been in use for about a century, and still makes up a rsmall proportion of grid operations. It has very specific requirements that aren't available everywhere. It's not an end-all solution for energy storage.