Thank you all for your interesting observations!
I will try to answer:
So you would continously store PV energy in, say batteries then, and when all the ammonia has vaporised you use the batteries to compress the ammonia again so it's ready for the next run.
Certainly, you could do that if you wanted to use the system for vehicle propulsion, as in Lamm's application.
But instead I want to use it as an electric energy storage system, so in this case the ammonia system should actually replace the batteries: the reversible motor/compressor is mechanically coupled to a synchronous electric motor (which can act as motor or generator) whose speed is controlled by an inverter. Since the electric system is stand-alone (no grid), the sum of all electric powers at any time is zero. Thus, the ammonia system will have to make up for the difference between the power produced by the PV plant and the power absorbed by the household appliances.
Let's see two example cases:
1) PV power = 2000 W and power consumed by appliances = 800 W; in this case the ammonia system should use the excess 1200 Watts of PV power to take low pressure ammonia from the low pressure tank and compress it back into the high pressure tank. The synchronous electric motor here acts as a motor and uses the excess power to drive the compressor.
2) PV power = 2000 W and power consumed by appliances = 3000 W (someone just turned on the microwave oven); in this case, the ammonia system will have to provide the missing 1000 Watts. So the high pressure ammonia will be expanded, the compressor will rotate backwards and act as a motor, and the synchronous electric motor will act as an electric generator, generating the needed 1000 Watts.
Sorry, I realize I should post some kind of graphics to explain things in a less confusing way, I'll try to do it soon...
Sounds like an interesting idea.NH3 is an excellent refrigerant.It is also very dangerous to people if it exscapes into the air and is at an exposer of 300 ppm or higher consentrations.Please do alot of research on ammonia refrigeration systems and materials before working with this, if you are not already considered an expert with this chemical.
Yes, that's one of the weak points: ammonia is dangerous to people. And so this kind of storage system could certainly not be installed indoors.
And even outdoors, many precautions should be taken, and there should be some kind of emergency sprinkler system to wash away any ammonia leakage in case of failures, I guess. There's as much work to do on the safety aspect as there is on the engineering aspect of the system.
Welcome, it is good to have you here, however you came by the forum. It is my understanding that nothing happens by chance however.
To speak to your ammonia system, there is a very large likelyhood of cross contamination between the high pressure ammonia tank and the low pressure water / mix tank. Thus making both tanks into medium concentration tanks.
Exactly! Cycle after cycle, the high concentration ammonia would have more and more water content in it, and the pressure of the high pressure tank would keep getting lower, making the system useless after some time. I have addressed this issue: I think I've solved it (at least I hope so) by having the high pressure tank be completely emptied (by opening a special valve) into the low pressure tank after every discharge cycle, so that water has no way of accumulating in the high pressure tank. More details will follow soon.
As for gravitational energy storage systems, they certainly are simple and work well, but I think the energy density is much lower.
OK, folks, good day / good night, see you soon!