alt Hacker News> The temperature swing can be much greater than 100 C.
No, because your steam will be at a lower temperature as you draw down the heat, bringing down efficiency.
Replies
pfdietz • today at 3:04 AM
That is wrong, and I already explained why.
> The temperature swing can be much greater than 100 C.
No, because your steam will be at a lower temperature as you draw down the heat, bringing down efficiency.
That is wrong, and I already explained why.
Realistic designs for this can achieve 450C delta t. Your energy store can store at ~1000C (slightly below rock melting point), and run steam turbines with a hot side of 600C and a cool side of 150C.
Over the season, your sand drops from ~1000 to ~600 (which is fine since your power needs drop in the spring)