4 ms·
> You may go back to your freshman physics textbook. I may, but I live in a country that doesn't use the word freshman, so I don't know which year physics text
by SECProto 4y ago
> You may go back to your freshman physics textbook.
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.
- lumost 4y agoNot the parent, but feel compelled to clarify the physics here. Delta E= force * distance always holds. This is the same physics of a car breaking or a jet accelerating. However a more general formula would be the integral of net force over distance.
- SECProto 4y agoYes, I was just suggesting that force times distance is not relevant to energy storage as gravitational potential unless the distance is vertical.
- deleted 4y ago[deleted]
- ncmncm 4y agoGravitation is not the only force. Even without local "freshman" classes, you may look it up in any dictionary. Or, just stop pretending.
- SECProto 4y agoI understand gravitation isn't the only force... how are you proposing to store energy? Other options (beside pumped hydro as gravitational potential energy storage) that come to mind are flywheels, springs, or batteries .... all of these technologies have existed for more than 100 years, and batteries are the only ones currently growing in usage - there's a good reason for that.
- ncmncm 4y agoBatteries are being used primarily in electric vehicles, for, as you say, good reasons, and for domestic backup. For bulk utility storage, batteries are the most expensive choice, although battery cost is still falling fast and numerous utility-adapted chemistries are competing. 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.