New forum on energy storage systems?

eschposito

New forum on energy storage systems?
« on January 3rd, 2016, 05:32 AM »
Hello everybody, I'm new here,
I came across open-source-energy.org by chance.
I've already done some open source work on
energy, although I don't have much time for it, take a look at:

http://nerdprogram.wordpress.com

and

http://homemadewatts.wordpress.com

Briefly, I believe that photovoltaics is the key energy, because PV panels
are affordable, simple to install and long lasting.
The problem is, in my opinion, energy storage. I'm studying  a physical energy storage system using ammonia-water solutions,
it seems promising but I have to make a prototype to verify that.

How about opening a new forum on energy storage?
Thanks and best wishes for a happy 2016 to everybody

Heuristicobfuscation

Re: New forum on energy storage systems?
« Reply #1, on January 3rd, 2016, 06:06 AM »
Website is interesting!..Welcome...

eschposito

Re: New forum on energy storage systems?
« Reply #2, on January 4th, 2016, 02:40 PM »
Thanks!
I'll spend a few more words to explain:
the basic idea is not new (as almost nothing is): it is based on the properties of liquid ammonia (NH3), which
at ambient temperature has a high vapor pressure. If mixed with water, however, forming a weak ammonia-water
solution, it has a low vapor pressure. This was applied in the 1800's by inventor Emile Lamm to the propulsion of
the streetcars of New Orleans. His system, which you can find in US patent 105,581 (you can download it from uspto.gov)
has a high pressure liquid ammonia tank, in which ammonia evaporates, is expanded, propelling the streetcar, and then
is discharged in the low pressure tank, containing ammonia-water solution, where it condenses.
In my storage system, I'de like to use this same layout, but coupling the reciprocating motor with an electric generator, and
making the whole system reversible.
This way, when the high pressure ammonia evaporates, it makes the reciprocating motor and generator axis rotate, and so generates electricity for the household appliances. On the other hand, when excess PV power is available, it is used to backwards-rotate the generator, which acts as an
electric motor, and makes the reciprocating motor act as a compressor, taking ammonia vapor from the low pressure ammonia-water tank
and compressing it back into the high pressure tank, where it restores the backup energy reserve in the form of stored liquid ammonia.
Hope this is clear enough... Any comments are welcome.
Bye!

Lynx

Re: New forum on energy storage systems?
« Reply #3, on January 4th, 2016, 10:05 PM »
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.
If there's low effect usage during a hot summer's day chanses are you'd risk over charging the batteries, so in that case maybe you'd need a charging monitor for switching over to a battery powered electricity output using, say an inverter then, which drains the batteries down to say 90% of full charge (which means you only use 10% of the total battery capacity) and then switches back to the ammonia again.

I have a vivid imagination so I can probably come to think of a whole lot of "what if......." scenarios similar to this one, some of which probably also could warrant installing some kind of safeguard in your system, so I'll try not to become too annoying here :-D

Enrg4life

Re: New forum on energy storage systems?
« Reply #4, on January 5th, 2016, 09:21 AM »
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.

kenssurplus

Re: New forum on energy storage systems?
« Reply #5, on January 5th, 2016, 11:02 AM »
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. If you could use gravity to separate the tanks such as an hydrogen / ammonia / water evaporation fridge uses, that might be an alternative to think about as well.

Ammonia absorption refrigerator - wikipedia

A few years ago, I had worked up the concept of a solar refrigerant ferris wheel as an energy generator.  Never did anything more than the conceptual drawings, as it too would shut down after dark.

If your energy storage system would efficeintly pump the fluid up to a higher tank, and then use that gravity fed fluid whenever you needed for power through gravity flow, that swould be an interesting energy storage system vs the pressure one you've described.  I'm just not sure whether it would be a better COP  (Coefficient Of Perfomance) than any other energy storage system.  Have to run calculaltions and simulations to get a better idea.

Anyway, keep thinking and trying.  Don't give up because of what someone might say (including me:-)

 

eschposito

Re: New forum on energy storage systems?
« Reply #6, on January 5th, 2016, 02:56 PM »
Thank you all for your interesting observations!
I will try to answer:
Quote from Lynx on January 4th, 2016, 10:05 PM
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...
Quote from Enrg4life on January 5th, 2016, 09:21 AM
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.
Quote from kenssurplus on January 5th, 2016, 11:02 AM
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!