Right, you're just describing traditional pumped storage. I suppose I should clarify because I didn't actually say what the advantage was, just the ways that the two designs are similar, but different.
In short, the advantage is that it exploits the same concept but in a very different way that avoids the pitfalls of traditional pumped storage.
The (dis)advantages:
- Safety. Dam failure is pretty catastrophic (see Vajont Dam disaster.) Although it's yet to be seen what failure of this device would look like, it's likely to be much less threat to human life. It would probably kill or deafen nearby marine life.
- Ecological concerns: a dam flooding a mountain valley destroys possibly unique ecosystems, and causes uncontrolled greenhouse gas emission as all the vegetation now underwater rots
- Land availability: land is at a premium, but seabed is abundant
Also, mountains for pumped storage are not always near population centers, and are often not near sources of renewable production that need the pumped storage. In that case, you have to transmit power from its point of generation to its point of storage to its point of use. In this scenario, with these spheres potentially being used as anchor points, the transmission distance between generation and storage is ~700m, and then you just need to transmit to your nearest coastal city of choice.
In short, the advantage is that it exploits the same concept but in a very different way that avoids the pitfalls of traditional pumped storage.
The (dis)advantages:
- Safety. Dam failure is pretty catastrophic (see Vajont Dam disaster.) Although it's yet to be seen what failure of this device would look like, it's likely to be much less threat to human life. It would probably kill or deafen nearby marine life.
- Ecological concerns: a dam flooding a mountain valley destroys possibly unique ecosystems, and causes uncontrolled greenhouse gas emission as all the vegetation now underwater rots
- Land availability: land is at a premium, but seabed is abundant
Also, mountains for pumped storage are not always near population centers, and are often not near sources of renewable production that need the pumped storage. In that case, you have to transmit power from its point of generation to its point of storage to its point of use. In this scenario, with these spheres potentially being used as anchor points, the transmission distance between generation and storage is ~700m, and then you just need to transmit to your nearest coastal city of choice.