Commercial Demonstration Unit August 2020 – Arbedo-Castione
With wide-spread hydropower facilities, constant threats of avalanches and mud slides, as well as trains having to bridge altitude differences all day, Alpine country Switzerland knows a thing or two about potential energy: the energy that can be won by lowering big masses of matter and converting it into kinetic energy.
But now they might be pushing it a little too much, as they are embarking on an uphill-struggle, pun intended.
Reuters – Energy Vault, a developer of utility-scale battery storage technology backed by SoftBank Group Corp (9984.T) and the venture arm of Saudi Aramco (2222.SE), has raised $100 million in a funding round, its chief executive told Reuters on Tuesday (21 Aug 2021).
Energy Vault offers a design of a gravity storage systems that stacks 35 ton concrete blocks upon each other with cranes to build towers, converting excess electricity from regardless which source, into potential energy. The density of concrete is about 2.4 times that of water. If electricity is required, the tower is torn down in a (hopefully) controlled manner. Round-trip efficiency 90%. In Switzerland, the concrete blocks can be produced locally. Intended max. tower height: ca. 130 meter, a large church tower. Capacity: 35 MWh.
To illustrate the point, here my holiday pictures of 2012:
[deepresource] – Mattmark Hydro Power Plant
This is a medium-sized storage, able to produce 130 MW for merely a couple of hours. Total storage capacity of the lake: 77,500,000 m3 or 77,500,000 tonnes at a height difference of almost 1500 m or 254.5 GWh in energy terms. In other words, the midsized mountain lake of Mattmark contains 7300 times more energy than the proposed concrete tower. Switzerland has 556 hydroelectric power plants.
The gravity battery could be ideal to illustrate the concept of potential energy to students, but one of those suffice for that purpose. To solve the energy storage problem, they are merely a gimmick. 35 MWh, that’s the equivalent of 1000 kg hydrogen, that can be stored as NH3 or methanol or borohydride in a container of a few m3.
[reuters.com] – SoftBank-backed storage developer Energy Vault raises $100 mln
[wikipedia.org] – Energy Vault
[energyvault.com] – Energy Vault company site
[Google Maps] – Arbedo-Castione Energy Vault