4 ms·
For fun, let's say you have a 20-ton container, and you raise it up the rail by 100m. The stored gravitational energy is about 5.5 kWh. According to Wikipedia
by yongjik 10mo ago
For fun, let's say you have a 20-ton container, and you raise it up the rail by 100m. The stored gravitational energy is about 5.5 kWh.
According to Wikipedia, Tesla Powerwall 3 has 13.5 kWh of capacity: more than two 20-ton containers raised to 100m, assuming perfect efficiency. It costs $7,300, small enough to put in your house, and also (more or less) safe enough to put in your house, unlike a 20-ton container on a rail barreling down a slope, which probably needs professional hard-hat maintenance crew.
So consider me skeptical.
- napkinartist 10mo agoYou've got a free order of magnitude issues. First, a rail car typically is closer to 100 or 125 tons. 20 tons is nothing. And the sites they are selecting likely have much more than 100 meters of vertical distance. 1,000 meters would not be unreasonable in some areas, though most are probably smaller. So a single car in this system is probably delivering 25-300 kWh of capacity depending on elevation and mass. And it scales linearly with mass, elevation, and storage space at the apex. Push 100 cars up and you've stored 2.5-30 mWh. Their demonstration effort plans to store 12.5 mWh. It doesn't seem totally unreasonable. It's at least within the umbrella of.... maybe, but friction is going to eat a ton of energy.
- Kichererbsen 10mo agoIs `mWh` Mega-Watt-Hours? Reads like Milli-Watt-Hours to me, which is obviously not what you intended. I'm used to MWh?
- cogman10 10mo agoYou are correct. mWh is "milli-watt-hours" MWh is "Mega-watt-hours".
- napkinartist 10mo agoPhone typing, apologies. Too late to edit it.