2 ms·
Your argument appears flawed. The mass is just a counterweight. It can easily be re-used over and over again like the weights in a grandfather clock. It can b
by jqpabc123 2y ago
Your argument appears flawed.
The mass is just a counterweight. It can easily be re-used over and over again like the weights in a grandfather clock. It can be made of almost anything. Compressed earth for example is a cheap and popular option.
The one time production cost of the re-useable counterweight is relatively insignificant compared to the ongoing economic benefit and utility of energy storage.
The skyscraper itself would presumably have other uses beyond just being a "gravity battery" in order to justify it's production cost. If not, then a building of more modest height can be used ... or no building at all --- simply create a shaft in the ground.
These options can be comparable (if not lower) in cost to pumped storage lakes and can be located virtually anywhere without geographic restrictions.
- 2_cents 2y agoFine. Let's do a quick calculation. You said creating a shaft would be as cheap as pumped storage. So I tried to find the costs involved and hit upon a price list for drilling wells. https://haynesandsonsllc.com/wp-content/uploads/2017/02/Price-list.pdf https://haynesandsonsllc.com/wp-content/uploads/2017/02/Pric... According to that the price for a 420 foot deep hole with a 10 inch diameter is around $30,000 Assuming we put a lead weight inside that has half the volume of the entire shaft (3.25 cubic meters) and a mass of 37 tons we end up with a stored energy of 6.5 kWh. Since the lead costs $70,000 we are looking at a price of $15,400 per kWh. Pumped hydro is around $100 to $200. If you use something cheap like concrete or compressed earth you can store 5 times less energy so you'd end up with even worse numbers. And I think it goes without saying that a skyscraper is a lot more expensive than a hole in the ground.
- jqpabc123 2y agoNow compare this to the cost for a pumped hydro storage facility. Be sure to include the cost of land in a suitable geographic location.