You can store electric energy by transforming it into two electrochemical half-cells out of balance. (The half-cells constitute the plus- and the minus-pole of a battery.) Or you can transform it mechanical energy which pumps water towards the upper side of a water reservoir dam and the energy is stored as a gravity-potential.

How do you store kinetic energy?

And how do you regulate the amount of energy you suck out of the moving rope? The only method I see is by controlling the angular momentum of a rotation device and this would require cogs with real-time-adjustable diameters.






So, even if kinetic energy has less transmission-losses, electric energy offers more comfort and better miniaturization.

You could either use it on site or, in the case of the kite, avoid lifting the weight of a generator and convert the wind energy to electricity on the ground.

In most mechanical application of energy, the energy to perform them mechanical act is only applied as long as the function is performed. Once they is not need to perform the function, the energy use can be cut to zero.

You only need to store energy, if creation of that energy is NOT related to its use. On my bicycle, I do NOT need to store energy as I peddle along, I am only using the energy NEEDED to go forward, no excess energy.

The problem with electricity is that the creation of electricity is often done independent of the demand for electrical energy. In most electrical generators, since it takes time to turn on, and then up or down, and then off the electrical generators, you end up with times of excessive electrical generation (Which has to be stored for later use) or a shortage (When people get browns outs and black outs). The easiest electrical generation to turn on and off is Hydro electrical, thus you example of using electrical power to use excess electrical power to pump water uphill for later use when the electrical power demand exceeds the base load.

In a Rope type system, the energy is applied to the "Rope" only when it is needed. Thus you can turn off or on the power when it is needed. No Excess power, not shortage of power. This is also its limitation, you have no way to increase energy use without building an entirely new system. With an electrical system, if demand increases, you can increase electrical power into the system with just minor upgrades in the lines between the electrical generators and the end users.

If the rope system is to long to be turn on or off as needed, then you can run its 100% all the time. With increase pull on the rope when you have increase resistance by someone using the "rope" (This is how the San Francisco cable cars work, the cable is moving all of the time, put when a cable car "grabs" the cable, that increases tension on the line which leads to increase input to pull the cable, When the Cable is released, energy demand drops as does the energy put into the system). Less efficient then a on and off system, but NOT by much if one stays within a range mentioned in the article. Also remember all that is needed on the cable car is a mechanism to grab the cable, no engine to weigh down the cable car. i.e. no extra weight for the cable to pull).

If you have enough objects using the rope (Again look at the Cable Cars of San Francisco), the shear number can compensate for each other as to the ups and down of energy needs. Incline planes have many of the same advantages, one car going down, equals in weight, the car going up and they counterbalance each other. Thus the only power actually used is to propel the CARGO up and down (When the Pennsylvania Canal and Old Portage Railway was built in the 1830s, it was for this reason incline were used, the steam engines of the time period were to small to hull themselves, their cars AND their cargo over Allegheny Mountain, but they were big enough to hull the cargo, which is all they had to do when hulled up an incline plane).

In most rope systems, any loss of energy had more to do with moving the rope along, then in any other factor, thus minimum opportunity to use this wasted energy for any other purpose. On the other hand, that we are talking about short bursts of energy, that only had to be produced when actually used, is a huge energy saving over having to produce a base load. Thus the energy savings is huge by the simple fact of NOT having that much energy wasted by having to operate the energy source more then needed. The famous comment, the best way to save energy is just to turn it off.

Side note: The above is hard to do, most direct "rope" system that survive to this day, use electrical power as their power source. Thus most Inclines and even the San Francisco Cable Cars use Electricity as they direct energy source, something NOT actually required or even done in the 1800s, when most Inclines were steam or even water driven (Using electricity to propel the cable is more efficient then the steam engines that did it in the 1800s, but using cable is more efficient then using electricity directly on the cable cars, when it comes to operation on the road of the Cable Cars). Steam was the original source of energy for the Cable Car's Cable and the various Inclines in the US, but most replaced their steam engines with electrical motors decades ago. I bring this up to show that while rope can be more efficient then direct electrical system, it may still be the most efficient way to produce the energy into a rope system, but we when we look at these "Alternatives" we have to understand we have to look at them from them from an energy input to energy out put situations, not just a post electrical system.

One of the few places in Delaware worth touring is the Hagley Museum, a monument to the early gunpowder making days of the DuPont empire. It was set on a stretch of and powered by the Brandywine River. They had very sophisticated workshops using water power transmitted by ropes and belts.

http://www.hagley.org/library/exhibits/brandywine/hagleysite.html

My in-laws live a bit south of Rehoboth. Maybe we can drive to the north end and tour it sometime.

When the author mentioned modern materials, it got me thinking that if one ever did want to pursue this kind of approach, it seems like an application that begs for nanotube-based cabling. Assuming somebody learns to manufacture nanotubes in that kind of volume at an affordable price point.

The SF Cablecars still run by Wire Rope.
You can see a bit of it from the museum walkway. Don't recall if they have a tour for those of us that love to poke around such stuff.

In another century we'll be exploring the cosmos by remote viewing. That is, some guy takes some mushroom, closes his eyes for a while and then says, "The beings I see on Epsilon Eridani III have a message for you..."