4 ms·

Lifting heavy bricks to store renewable energy

10 points by sieste 5y ago

jacquesm 5y ago
You could go inground rather than just up, repurpose old mines, and maybe use a very heavy fluid.
downrightmike 5y ago
Stupid. A complete waste of cement. Would be better to just repurpose all the old railroad lines no one uses and use the gravity lift that way. Iron > cement
ncmncm 5y ago
We have much better storage methods. The most mature is "pumped hydro" to a water reservoir up a hill. (Not the same as a hydroelectric dam, which needs, and damages, a watershed.) We are building liquidified-air storage. (Liquifying air is very mature tech.) We are preparing underground hydrogen repositories, in places where we had been used to banking natural gas. We are building ammonia synthesis factories. Less mature tech is also ramping up. We are building out factories to build out iron-air batteries. A 20,000 ton weight suspended on cables in a deep mine shaft. Pumped hydro from a deep earth cavity. Pumped hydro out of deep ocean tanks. Methane and kerosene synthesis. The most remarkable quality of energy storage tech is how its cost is plummeting even faster than solar and wind generation. The chemical synthesis and liquified-air tech is interesting in that the production apparatus remains useful even after the tanks are full, and building out tanks for more storage is very cheap. They call attention to the separate qualities of storage that will be optimized for each use: (1) How fast can it bank energy, (2) how much power can it release when needed, (3) How quickly can power output be adjusted, (4) how much of the energy you put in do you get back, (5) Is the storage medium or equipment useful for more than storage, (6) Is the stored energy transportable? Places at high latitudes, and in general places where the mix of renewables and transmission-line power are not stable enough, can still ship in and stockpile chemical storage banked in places with reliable power. Equatorial, coastal desert land will be an excellent place to site solar collection for this purpose: Coastal Peru, Boa Vista in the Cape Verde Islands, coastal Mali or Senegal, numerous sites on and near the Arabian peninsula and the Horn of Africa, northwestern Australia. Other coastal sites with reliable wind, likewise. (Political stability is likely to be more important than convenience, though.) Perhaps the most surprising thing about storage is that, in common cases, its round-trip efficiency doesn't matter very much. Other things have come to matter more, as raw generating cost continues on down. Hydrogen is a good example: it is so useful, industrially and as a feedstock for other chemical synthesis, that use for storage is just an easy bonus. Ammonia, similarly; demand for fertilizer and ship fuel makes production a major source of revenue when the storage tanks are full.
- netizen-936824 5y ago
  Is the conversion of pumped hydro any different than a brick of concrete that has been raised to the same height with the same mass as the water? They should have the exact same potential energy
  - ncmncm 5y ago
    Technically you are correct, in broad strokes, but the important differences are in the details.
    - netizen-936824 5y ago
      What implementation advantages are there to liquid vs solid?
      - ncmncm 5y ago
        (1) You don't need to make the liquid. (2) You don't need to make the hill for the liquid. (3) You don't need to worry about wind making your system fail. (4) The amount of energy you can store has no relation to the amount of equipment you need to build. (5) Your equipment has only 3 states: stopped, pumping, or draining. (6) There are only 3 states of the whole system: empty, partly full, and full. Pumped hydro admits interesting variations. The reservoir may be deep underground. The reservoir may be a rigid tank deep under the sea. The fluid may be air, and the reservoir a bladder tank deep under the sea, or under the water table. Solid admits one interesting variation: crane at ground level, a single extremely weight suspended in an existing, deep mine shaft.
zugi 5y ago
This is such a clear and obvious way to store energy that I assumed it had long ago been analyzed and assessed to fall short of other options in terms of energy efficiency, capacity, and cost. Those and other numbers are what matters, and the article doesn't provide any of them. Without data on how its efficiency, capacity, and cost compare to pumped hydro, batteries, flywheels, and other alternatives, it looks like a student science project done at larger scale.
michaelcampbell 5y ago
The Youtuber "Adam Something" has a pretty brutal takedown of this idea. He brings up some good (counter)points to this idea.
- Hasnep 5y ago
  The energy vault is a dumb idea, here's why https://youtu.be/iGGOjD_OtAM https://youtu.be/iGGOjD_OtAM
  - sieste 5y ago
    Had a good chuckle over this video, thanks for posting. Main argument is that all weak points of the stacking bricks method (sensitivity to wind, expensive material, problematic up/down transport) are solved by pumped storage hydroelectricity.

10 points by sieste 5y ago

You could go inground rather than just up, repurpose old mines, and maybe use a very heavy fluid.

Stupid. A complete waste of cement. Would be better to just repurpose all the old railroad lines no one uses and use the gravity lift that way. Iron > cement

ncmncm 5y ago

We have much better storage methods. The most mature is "pumped hydro" to a water reservoir up a hill. (Not the same as a hydroelectric dam, which needs, and damages, a watershed.) We are building liquidified-air storage. (Liquifying air is very mature tech.) We are preparing underground hydrogen repositories, in places where we had been used to banking natural gas. We are building ammonia synthesis factories. Less mature tech is also ramping up. We are building out factories to build out iron-air batteries. A 20,000 ton weight suspended on cables in a deep mine shaft. Pumped hydro from a deep earth cavity. Pumped hydro out of deep ocean tanks. Methane and kerosene synthesis. The most remarkable quality of energy storage tech is how its cost is plummeting even faster than solar and wind generation. The chemical synthesis and liquified-air tech is interesting in that the production apparatus remains useful even after the tanks are full, and building out tanks for more storage is very cheap. They call attention to the separate qualities of storage that will be optimized for each use: (1) How fast can it bank energy, (2) how much power can it release when needed, (3) How quickly can power output be adjusted, (4) how much of the energy you put in do you get back, (5) Is the storage medium or equipment useful for more than storage, (6) Is the stored energy transportable? Places at high latitudes, and in general places where the mix of renewables and transmission-line power are not stable enough, can still ship in and stockpile chemical storage banked in places with reliable power. Equatorial, coastal desert land will be an excellent place to site solar collection for this purpose: Coastal Peru, Boa Vista in the Cape Verde Islands, coastal Mali or Senegal, numerous sites on and near the Arabian peninsula and the Horn of Africa, northwestern Australia. Other coastal sites with reliable wind, likewise. (Political stability is likely to be more important than convenience, though.) Perhaps the most surprising thing about storage is that, in common cases, its round-trip efficiency doesn't matter very much. Other things have come to matter more, as raw generating cost continues on down. Hydrogen is a good example: it is so useful, industrially and as a feedstock for other chemical synthesis, that use for storage is just an easy bonus. Ammonia, similarly; demand for fertilizer and ship fuel makes production a major source of revenue when the storage tanks are full.

netizen-936824 5y ago
Is the conversion of pumped hydro any different than a brick of concrete that has been raised to the same height with the same mass as the water? They should have the exact same potential energy
- ncmncm 5y ago
  Technically you are correct, in broad strokes, but the important differences are in the details.
  - netizen-936824 5y ago
    What implementation advantages are there to liquid vs solid?
    - ncmncm 5y ago
      (1) You don't need to make the liquid. (2) You don't need to make the hill for the liquid. (3) You don't need to worry about wind making your system fail. (4) The amount of energy you can store has no relation to the amount of equipment you need to build. (5) Your equipment has only 3 states: stopped, pumping, or draining. (6) There are only 3 states of the whole system: empty, partly full, and full. Pumped hydro admits interesting variations. The reservoir may be deep underground. The reservoir may be a rigid tank deep under the sea. The fluid may be air, and the reservoir a bladder tank deep under the sea, or under the water table. Solid admits one interesting variation: crane at ground level, a single extremely weight suspended in an existing, deep mine shaft.

zugi 5y ago

This is such a clear and obvious way to store energy that I assumed it had long ago been analyzed and assessed to fall short of other options in terms of energy efficiency, capacity, and cost. Those and other numbers are what matters, and the article doesn't provide any of them. Without data on how its efficiency, capacity, and cost compare to pumped hydro, batteries, flywheels, and other alternatives, it looks like a student science project done at larger scale.

michaelcampbell 5y ago

The Youtuber "Adam Something" has a pretty brutal takedown of this idea. He brings up some good (counter)points to this idea.

Hasnep 5y ago
The energy vault is a dumb idea, here's why https://youtu.be/iGGOjD_OtAM https://youtu.be/iGGOjD_OtAM
- sieste 5y ago
  Had a good chuckle over this video, thanks for posting. Main argument is that all weak points of the stacking bricks method (sensitivity to wind, expensive material, problematic up/down transport) are solved by pumped storage hydroelectricity.