Silly question - could tires be used to do this? I mean, could one improvise a storage system via a stack of car tires?
Ditch the Batteries: Off-Grid Compressed Air Energy Storage
201–210 of 238 posts
Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage
#202I was quite excited by compressed air storage when Lightsail came into the picture almost 5-7 years ago. Sadly, they could not make the economics work and ended up pivoting into a company that sells carbon fibre tanks for high-pressure storage. As someone who follows the energy space closely, Lithium ion batteries now have so much momentum and $$$ pumped into them via R&D work, it's going to be hard for competing ene…
Aren't flywheels used in datacenters to cover the split second between when the power goes out and the generators kick on?
Some of them do, but the overhead is ridiculous. I don't have the data in mind, but I think that the NoBreak brand consumes 20kW+ just idling. It's ridiculous
Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage
#203> However, to store 360 Wh of potential electrical energy, the system requires a storage reservoir of 18 m3, the size of a small room measuring 3x3x2 metres. The authors note that “although the tank size appears very large, it still makes sense for applications in rural areas”. This would light a home for an hour, with LED bulbs and careful usage. And all it requires is a room-sized storage tank. So if I wanted somet…
An LED light bulb uses 11 watts. You must be lighting your home with 33 bulbs if that only lasts you an hour. If you only use 4 bulbs, that will last over 8 hours.
My home as got many 3W led bulbs for small lamps. 7W is the norm
Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage
#204Earlier quoted context omitted.
> it's a fairly energetic explosion So is a lithium battery explosion. So is a gasoline explosion. So is a flour mill explosion. So is a wind turbine explosion. Energy is energy, and losing control of energy is never great, no matter where it comes from. So while I catch your meaning, it might be better to phrase it with respect to how controllable that energy is. From what I know of flywheel storage, the problem mos…
Are buried flywheels used in practice? Is the flywheel axis aligned with the Earth rotation axis? Do they pull a vacuum around it?
Yes, in cases, to the first two. Containment is frequently buried concrete vaults.
Not AFAIK for the last, though precessional torque bearing load is a nontrivial consideration.
Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage
#205Earlier quoted context omitted.
On the other hand, flywheels can be easily buried underground, and easily contained. The max power of a flywheel is known, so it's just a matter of putting enough concrete between humans and flywheel, a straightforward and inexpensive engineering problem. And unlike compressed air, the containment isn't under constant, wearing pressure.
You can bury the air tanks too and avoid most of the danger, but that's expensive and makes them harder to maintain. The big advantage of flywheels is that when they fail you know the energy will be discharged in a particular plane. You can orient them such that nothing vital is in that plane (like your house!). With compressed air all bets are off.
SCUBA tanks have a "burst-disk" or a weaker part of the tank that is designed to fail first, rather than the whole thing exploding and launching shrapnel. It's still violent and can throw some shrapnel, but it's much less. Also when SCUBA shops fill tanks they usually put them into a container that would somewhat contain that.
I imagine something similar could be done. It's not like there are zero safety mechanisms with compressed air.
Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage
#206Earlier quoted context omitted.
It's kind of bizarre how nuclear had achieved a sort of counterculture renaissance. It has many, many drawbacks too numerous to go into here that are technical and sociological in nature. And anyway, you tried to be too clever. I said "non-renewable" and not "carbon free" just to avoid this conversation. Unless you can start synthesizing utility grade quantities of well-behaved fissile material at a net energy surplu…
> Unless you can start synthesizing utility grade quantities of well-behaved fissile material at a net energy surplus then it's not renewable even if we have decades/centuries of supply. Someday, even the Sun will run out of fuel. In the long run, we are all dead - unless someone figures out how to reverse entropy. http://www.multivax.com/last_question.html
If you listen very hard, you can hear my eyes rolling through your computer. But I enjoyed reading the story and begrudgingly admire your pedantry on the matter!
Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage
#207Earlier quoted context omitted.
Except we've had a carbon free baseload tech for decades now.
It's kind of bizarre how nuclear had achieved a sort of counterculture renaissance. It has many, many drawbacks too numerous to go into here that are technical and sociological in nature. And anyway, you tried to be too clever. I said "non-renewable" and not "carbon free" just to avoid this conversation. Unless you can start synthesizing utility grade quantities of well-behaved fissile material at a net energy surplu…
It's not renewable, but it is closer to carbon-neutral than fossil fuels. Advocates generally push it as a stopgap measure for climate change, after we transition away from baseload coal and before we transition to baseload renewables.
Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage
#208Earlier quoted context omitted.
Aren't flywheels used in datacenters to cover the split second between when the power goes out and the generators kick on?
Some DCs do, but the need to keep them spinning 24/7/365 is a big maintenance issue, so given the advances in battery tech, I'd assume batteries would supplant flywheels for cost and safety reasons.
> but the need to keep them spinning 24/7/365 is a big maintenance issue
So is keeping batteries up to date. Many a failure has been attributed to stuff like:
- batteries gone bad without anyone noticing over the years (lack of acid, crystallization, loose contacts, dust in cooling components, ...)
- switch-over between grid and battery inverters fails somewhere
- some part of the inverters fail when they're idling for years and then have to go into full load suddenly
A huge flywheel only needs bearing lubrication, that's it.
Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage
#209I have argued unsuccessfully in the past that this technique would be an excellent data center strategy. That is especially true if you had your data center near the Columbia river and its near constant winds.
Using wind power to compress into high pressure tanks, then when you need extra energy you pull it out and pipe the air expansion pipes through heat exchanges in the data center. That way heat from the data center goes to warming up the air (better efficiency when you feed it to the turbines) and it cools the data center which is part of what one might use the energy for in the first place.
If you put the air expansion pipes in a conveniently located source of water you could chill that water to freezing.
Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage
#210Earlier quoted context omitted.
Aren't flywheels used in datacenters to cover the split second between when the power goes out and the generators kick on?
I toured a datacenter 5 years ago or so - and yes, they had a big flywheel for temporary power loses (until they could get the generators running)
That's only if they don't /cant run the entire DC of battery -whilst the gensets come online this is how telco exchanges / central offices work and important ones may have power supplied via different routes.