3 ms·
I didn't read the article super-carefully, but my impression was that they were using the heat of vaporization of water for energy storage, not PdV work of the
by lutorm 14y ago
I didn't read the article super-carefully, but my impression was that they were using the heat of vaporization of water for energy storage, not PdV work of the air. I haven't done a calculation, but my guess is that this is much more efficient.
- DaniFong 14y agoYou have to store both. Also, you can't vaporize much air at low temperatures, which we aim for. You have to hold onto water for its sensible (no evaporation) heat capacity.
- robomartin 14y agoDo you have a number for the amount of air and water you need to store per kW-h of energy delivered to the load? What's the real energy efficiency of the system? What's the estimated energy loss per unit time of the storage system?
- DaniFong 14y ago1^m3 of 300 bar air = approx. 30 kwhr. Approximately 1/4th of that in water storage will hold the heat. We're aiming at a daily loss of 1%, but it caps out at 10% relative (~7% absolute) because the Energy Out/Energy In is proportional to T_exp/T_comp (in an absolute scale) -- if the temperature drops to ambient, T_exp is only slightly lower in an absolute scale.