T1B

Some important parameters that differentiate various technologies:

• Specific energy (stored energy per unit weight)
  Energy density (stored energy per unit volume)
  Round trip efficiency (energy out divided by energy in)
  Scalability (can you make it big or small or anything in between)
  Cycle time (how long does it take to charge and discharge)
  Portability
  Cost (cost per unit of capacity)
  Environmental conditions (meaning what conditions does it require to operate effectively)
  Safety
  Others...

All of these can make a huge difference depending on what you want to use it for.

Take pumped hydro, for example.

Round trip efficiency is between 70% and 80%, from what I understand, if you have an efficient pump and turbine. OK but not great (Li ion batteries can be over 90% depending on the load characteristics).

Energy density, specific energy and scalability aren't so good, but these are offset by the relatively low cost compared to the other technologies. That's assuming you have the right place to put it. You need a reservoir of some kind and a hill. You can't just put these things anywhere. You also need water and a relatively cheap source of off-peak power due to the lower efficiency. It doesn't make much sense to lose 25% of your energy for load shifting unless you have a large price difference between on-peak and off-peak power.

Compare hydrogen to Li-ion batteries for another example.

A lot of people look at hydrogen as a fuel but, practically, it's an energy storage medium. It's mainly used to run electric fuel cells, which are a very clean way to generate electricity. However, you can't just pump it out of the ground. There are two main ways to "make" hydrogen 1) water electrolysis and 2) reformation of methane (natural gas). Water electrolysis uses electricity to separate water into hydrogen and oxygen. Reformation is a thermochemical process that produces hydrogen and CO2 from methane. Hydrogen produced by #1 is a renewable process (assuming you're using solar or wind power or another renewable source of electricity) but #2 is NOT renewable, because it uses a fossil fuel, and it also produces CO2 as a byproduct.

A lot of people have gotten excited about the "hydrogen economy" supposedly coming in the future. I can see the potential but we have a long way to go. Electric fuel cells are potentially used in a lot of places that Li-ion batteries could be used. They've been touted as the prime movers for the cars of the future. In reality a fuel cell car is an electric car with a motor that's run from the electricity produced by an on-board fuel cell.

Li-ion batteries have probably the best scalability of any of the technologies now available - they can run your watch or be combined into a 2 MW storage battery. Right now you can't power your watch with a fuel cell, but they can be made small enough for a car, or large enough for a 2 MW on-site generation system. For transportation, hydrogen fuel cells cars have a couple of practical advantages over batteries:

• Compressed or liquid hydrogen fuel has a much higher specific energy (MJ/Kg), especially if it's liquid hydrogen, though a comparable energy density (MJ/L). Meaning that they take up a similar amount of space but the hydrogen is much lighter. Keep in mind that a fuel cell car needs space for hydrogen storage, fuel cell and electric motor, where the all electric car just needs space for the battery and motor.
  
  Refueling hydrogen is (or can be) much quicker than recharging batteries, unless you have a system for swapping batteries.

The big advantage of batteries over hydrogen fuel cells is in efficiency. Assuming you start with a renewable source of electricity, like PV. You charge your car battery and drive away, probably getting 80% to 90% efficiency from PV generation to the motor driving your wheels. Start out with the same renewable electricity to produce hydrogen for a fuel cell. The efficiency of electrolyzing water to hydrogen is around 60%. Then you have to convert the hydrogen back to electricity using the fuel cell at an efficiency of probably 60% max. That gives you an overall efficiency of about 36%. So, it takes twice (or more) as much primary electrical energy to run a fuel cell car as a battery car. Plus batteries are a lot cheaper than fuel cells.

So, the only way fuel cells make economic sense as a renewable technology for the transportation infrastructure is if you have a huge source of cheap renewable electricity that you can't transmit by power lines (like miles offshore?).

OK I'm rambling. Sorry.

Here are some round trip efficiency estimates for comparison.

Dinsdale wrote:
Ohhhh reeeelllly?

I know that was the prediction, based on a theory.

So, got a link yo back that up?

Let me help -- you don't have a link, because those predictions never happened.

No shit? Then this must be some sort of internet hoax.....
http://www.c2es.org/newsroom/articles/s ... ate-change

Look I know you don't give a rats ass because it won't affect you, but how about your children (if you have any) or your nieces and nephews and their children? Man I'd hate to have you as a house guest because it's obvious you don't believe in leaving a place in as good or better condition than when you got there......

I'd hate to have him as a house guest just based on the cleaning bill for the drapes.

Goober McTuber wrote:I'd hate to have him as a house guest just based on the cleaning bill for the drapes.

The drapes would be nothing compared to the outright assault on your liquor cabinet.

I'm ready for you. I've upgraded the bunker:

Makes for an even worse house guest -- after a couple of bottles, your OL will probably start looking pretty good.

Goober McTuber wrote:I'm ready for you. I've upgraded the bunker:

Nice going CTRL-C Gobbles.

Dinsdale wrote:Makes for an even worse house guest -- after a couple of bottles, your OL will probably start looking pretty good.

Which would bring us full circle back to the drape cleaning bill.

Screw_Michigan wrote:

Goober McTuber wrote:I'm ready for you. I've upgraded the bunker:

Nice going CTRL-C Gobbles.

Nice sense of humor, paste-eater.

Goober McTuber wrote:I'm ready for you. I've upgraded the bunker:

TRoll StoP!!!!!!!!!!!!!


I can call my good friend Arch Angel and we can have a party!!!!!!!!!!!!!

Lead Acid Batteries...

So I happened to be auditing a customer's facility yesterday, and they have a bunch of lead acid batteries for energy storage.

In this case it's sort of like a huge UPS. All of their equipment is DC powered and it's run off the batteries. They take the AC off the grid, and rectify it to DC to keep the batteries fully charged. If the grid goes down they have enough storage in the batteries to run everything for a few hours - then the diesel backup generator comes on. It's critical for them to NEVER have to turn equipment off.

If climate change were as serious as it has been shilled as being, then the Al Gores and Leonardo DiCaprios wouldn't be jetsetting around the world contributing to it in a manner that says it's a fake crisis. Which it is-- as is evidenced by the carelessness of AGW proponent's lifestyles.

Case closed, jury is dismissed.

Rooster wrote:If climate change were as serious as it has been shilled as being, then the Al Gores and Leonardo DiCaprios wouldn't be jetsetting around the world contributing to it in a manner that says it's a fake crisis. Which it is-- as is evidenced by the carelessness of AGW proponent's lifestyles.

Case closed, jury is dismissed.

Your logic isn't logical.

The Gores and DiCaprios being assholes has nothing to do with the science. It doesn't prove or disprove shit.

Papa Willie wrote:

Mikey wrote:

Rooster wrote:If climate change were as serious as it has been shilled as being, then the Al Gores and Leonardo DiCaprios wouldn't be jetsetting around the world contributing to it in a manner that says it's a fake crisis. Which it is-- as is evidenced by the carelessness of AGW proponent's lifestyles.

Case closed, jury is dismissed.

Your logic isn't logical.

The Gores and DiCaprios being assholes has nothing to do with the science. It doesn't prove or disprove shit.

Gore was worth $800k in 2000. Now he's approaching billionaire status. You figure it out.

I can't figure it out, so why don't you explain it to me. What does Gore's net worth have to do with scientific research done by people he doesn't even know?

How much is Exxon Mobile worth? Shell Oil? Apparently you don't think they have any stake in this issue? Or maybe you believe that they're beyond promoting any obfuscation of the facts.

Bingo. It's a business-- a spurious one at that, but a business all the same. AGW is nothing more than a vehicle for a particular segment of society to profit off of others. And globally it is vast vehicle for the transference of the industrial West's wealth to the 3rd world. Marx must be smilingly when he's not being roasted by Satan.

Mikey wrote: Chilled water or ice (thermal storage)[/list]

Not sure if you've seen this, Mikey.

http://www.bbc.com/news/science-environment-37902773

Not much storage, but doesn't appear that large, either. It will be interesting to see how this works out.

Cryogenic Storage...is that where they're keeping Ted Williams?

Seriously, though, I've never seen that and it looks pretty interesting. Most thermal storage I've seen is on a much smaller scale - making chilled water or ice at night when rates are low, and storing it in a big tank on (or in) a building to use for cooling during the day.

It would be interesting to see the efficiency of going from the landfill gas (methane - basically the same as natural gas once it's cleaned up) to "liquid air" (they'll probably be using nitrogen) and then to electricity. It takes a lot of electricity to make liquid nitrogen - I don't know the exact process but it involves multiple steps of chilling and compressing. But compressing air is a pretty inefficient process - it creates a lot of heat in the process.

A pretty well written article. The author seems to know what she (I think) is talking about. Different storage technologies have different advantages and disadvantages, which make them more or less attractive depending on the specific application.

Interesting also that they brought up demand response, which is a big thing in California. There are big utility incentives for ADR (automated demand response) where the utility can send a signal to a facility to ramp down certain non-critical processes in anticipation of an demand event. There are also demand bidding programs where a facility can bid into the market for DR during specific demand events. I once worked on an M&V for an efficiency project at an air separation plant, where they take ambient air and make liquid nitrogen and liquid oxygen. They were basically switching from an older process to a new more efficient process. They got a big incentive for the efficiency project but also installed ADR and got a bigger incentive for that. This plant had huge cryogenic storage tanks for the nitrogen, like four stories tall and maybe 50 feet in diameter, from which they loaded the stuff onto tanker trucks. Because of the huge storage capacity they could shut down about 75% of the plant (about 7 MW) on short notice for a few hours and still keep loading the trucks.

Wouldn't want to be standing anywhere near those tanks when the big earthquake comes, though.

I do my laundry at night. Does that help?

We already have the means to store energy fairly efficiently. It is called hydro-gravity storage. What I question is using tax dollars to get people to put panels on roofs in places that make no sense. I think large scale solar in places where it makes sense is a good idea. And it has to be more efficient than to pay homeowners to ugly up their roofs, particularly where the isn't very reliable. As for wind, I feel kind of the opposite. Monster windmills look kinda cool, but they take an enormous amount of material and boxcars full of cash to build. I wonder if it might make sense to build more smaller ones.

Then use tiles instead of panels. Oh and clean your fucking yard.

Mikey wrote:All of their equipment is DC powered and it's run off the batteries. They take the AC off the grid, and rectify it to DC to keep the batteries fully charged.

Looking back through this... did I mention I dealt in lead-acid batteries for almost a decade?

Your pics are child's play.

If you want to see a mondo UPS, check out a hospital sometime (IIRC, it's the Blue outlets). Their equipment doesn't run on DC, but plain-old 110. It's rectified to DC, typically 240 (or they call it 240, to keep the 20-jar banks floated, the input is around 270Vdc), then it's inverted back to 110. There's multiple banks, so the 110 can be put in series, but most critical stuff in a hospital runs 110.

But I guess my point is, a hospital has some motherfucking lead in the basement. I think these days, it's almost exclusively AGM batteries, but I've seen it done with good old fashioned 2HT's (same 6V batteries that go in a golf cart. Actually a pretty crappy setup, since they're wet/Flooded/vented jars, which subject surrounding parts to corrosion, which greatly increases maintenance cost, but makes for much lower startup costs).

My point being, storing individual ions ain't the way, despite how much Elon Musk wants to corner the market on it. The other technologies we've discussed here are so much more promising.

I think it's cool Mikey is into this stuff, as I've been for decades. Unfortunately, I don;t have the education nor the smarts to build that better mousetrap. But it's all about moving shit from Point A to Point B, be it a compound or ions.

smackaholic wrote:It is called hydro-gravity storage.

Sounds awesome. Tell me more?

Sin,
Fucking Kansas

smackaholic wrote:Monster windmills look kinda cool, but they take an enormous amount of material and boxcars full of cash to build. I wonder if it might make sense to build more smaller ones.

They aren't really all that big. I see them heading down the freeway in a few pieces (we have buhzillions of them here. Which by my math means Texas has eleventeen billion thousand buhzillion -- West Texas is a sight to behold). But until a reasonable mass-storage technology proves workable, windmills are... wind dependent. Kind of a problem. Solar is big here, even though it's usually cloudy and the sun barely comes up in the dead of winter -- but they the panels still produce. And they kick like a mofo in summer when it's always sunny, and it's light from 4:30 to 9:45. In places where it snows frequently, the solar... not so much (although I guess they could siphon some juice off and heat the panels).

The Big Pickle wrote:

Goober McTuber wrote:I'm ready for you. I've upgraded the bunker:

TRoll StoP!!!!!!!!!!!!!


I can call my good friend Arch Angel and we can have a party!!!!!!!!!!!!!

You will need to bring Anique and she will need to perform Clintonesque "not sexual relations" on Herr McTuber.

Goober McTuber wrote:
You will need to bring Anique and she will need to perform Clintonesque "not sexual relations" on Herr McTuber.

Bro -- airfare from Ukraine would be a big expense. Seems like it would be cheaper to farm the job out to some local talent. Madison has "med school working girls," right?

Dinsdale wrote:

smackaholic wrote:It is called hydro-gravity storage.

Sounds awesome. Tell me more?

Sin,
Fucking Kansas

Never said it was the ideal solution for all places. It makes a bunch of sense in your neck of the woods as you have hydro and elevation variety in spades.

Another thing that might be worth looking into is using all that windpower to pump water from the mississippi, across TX, NM, AZ and dump it in the Colorado. This would alleviate the fact that the SW needs more water than they have. According to mr google, the low spot in the continental divide is about 3900 ft elevation, somewhere in NM, so pumping it from the east ought to be doable. You could recoup a fair bit of this power with increased generation on the various dams on the Colorado.

The libs would never let the "pump" price get anywhere close to that. Instead they will continue to offer subsides and have the tax payers cover part of the cost.

Moving Sale wrote:Then use tiles instead of panels. Oh and clean your fucking yard.

I am actually interested in the tiles. IF they can be produced at something close to a sane price.