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View Full Version : How a giant battery may save the world (osmium & irw)


Bloggingheads
12-16-2009, 04:36 PM

graz
12-16-2009, 04:41 PM
Link (http://apollo.bloggingheads.tv/diavlogs/24630)

look
12-16-2009, 11:12 PM
Great job, gentlemen. I appreciated the step-by-step explanation under Ian's questioning. I learned a lot. Looking forward to the next one.

Whatfur
12-17-2009, 07:38 AM
Interesting.

I may have mentioned that I exist off the grid for much of the winter months. Now I happen to do so in a tent, but that tent is set up a couple hundred yards from a buddy's log cabin. His cabin is what falls right into this discussion. Also off the grid, he has a system that utilizes wind power( 1, 6ft? turbine), solar power (4 3'x6' panels) , and a gas or diesel (dependant on which one is working) generator and a rack (a 12-20?) of lead/acid batteries.

I have not done a study of it but from him I know that although things are working, he is disappointed in much of it and the generators are running quite a bit. Personal observation has me being disappointed also as his needs are seemingly small yet he seems to have to be on constant vigilant watch...and I see that rack of batteries in the basement and it just seems like one should be able to run off them for a few days without any kind of regeneration...and that is just not the case. I will do a closer study this winter...usually I am already there by now, but although its been cold, they are lacking the snow that is my draw.

He is in the midst of building a larger log cabin next to the original as his wife is expecting and while I assume he is going to hook into much of the existing I also assume he is doing some rethinking about what he has and how it could be better.

Suggestions? Should he wait a bit before investing in a bunch of new lead/acids.

Are there other materials, over and above the Zinc/Alluminum/Lithium that have promise? How available is Zinc...no shortage scenerio like you allude with lithium? (When Bolivia was mentioned, I saw scenes of Butch Cassidy and the Sundance Kid run through IRW's head (http://apollo.bloggingheads.tv/diavlogs/24630?in=16:53&out=17:15))

A side note...I worked in a coal burning power plant a couple decades ago and I remember they had a huge battery room...I can't remember the exact purpose but I would guess now it was purely for backup for lighting needs in case they themselves lost power.

Instead of preventing, can the Zinc fingers be effectively scrubbed?

graz
12-17-2009, 10:08 AM
Did I let everyone know that in the latter part of December I celebrate a festival that includes gift giving? So my nephew will be receiving lots of electronic toys and games that are sure to run out of "juice" or battery power sooner or later.
Is it possible to have one huge battery that can run all the appliances via radio transfer of power? Will the effectiveness of the power-pack be affected by an increase in global or regional temperatures?
If I were to live off the grid, does that mean that I won't post on the internet?

Francoamerican
12-17-2009, 01:55 PM
The giant battery sounds like a good idea, at least to someone who knows nothing about chemistry. Keep up the good work, Osmium. I hope you succeed in devising the super-duper zinc battery before humanity runs out of juice. I invested in a company that manufactures zinc batteries to replace lithium batteries in hybrid cars. Not a great idea...so far at least. Few people want to buy hybrid cars.

Baltimoron
12-17-2009, 07:31 PM
After watching this report on rare earth extraction and processing (http://www.pbs.org/newshour/bb/asia/july-dec09/china_12-14.html) for use in alternative energy technologies, I'm wondering if research isn't green enough. Are any of these rare earth elements a part of your research, Osmium?

Thank you for the diavlog.

JonIrenicus
12-18-2009, 12:55 AM
This seems to be the only way to make renewables work for 100% of our power generation. Even then though, it is still a good idea to have some base load power generation though that we can throttle up or down on demand right?

Do we ever want to get to a place where we are using nearly 100% renewables for power generation?

And if not, what base load options should we use?


The main ones seem to be

coal
natural gas
nuclear

And all but the last spew toxins into the atmosphere, and unfortunately, the last will always be prevented from the irrational, so what is left for base load power generation?

cragger
12-18-2009, 12:54 PM
Good discussion. I particulaly appreciated the description of the problem as being one of grid level energy storage. The types of storage you considered - chemical energy in batteries or fuel cells and possibly storage in fields using capacitors aren't the only ways to store energy, though it's understandable you concentrated on batteries since that is what you work on.

A few initial thoughts spurred by the diavlog:

Considering the relative costs of renewable sources vs. the various fossil energy sources, the crossover point seems to be approaching. Solar costs per KWH have been coming down over time, and fuels increasing in cost, particularly for oil and gas-fired plants. These appear subject to steep cost increases in the near-term future, though it will likely be a while before coal costs go up steeply. Of course in comparing the costs per KWH one must also remember that the figures are very distorted by the externalization of considerable costs from the use of fossil fuels, costs now coming home to roost though not through market economics directly tied to the causes of those costs.

A couple of additional factors in solar's favor include creation of a distributed source system that offers advantages in resiliance and robustness over a centralized source system. As a partial solution to energy generation, solar output is well matched to the demand curve. Distributed generation, such as at the home level, also gives the advantage of generation at the point of consumption, reducing both transmission needs and transmission power losses.

A couple thoughts on storage. Though the batteries Osmium is working on are hoped to last longer than the deep discharge cells typically used in off-grid systems now (say 8-10 years rather than "several"), the installation and maintenance costs of the system of cells and attendant electronics to control charging and do power conversion still don't sound likely to be trivial. It would take a pretty steep price curve for power depending on real-time demand to motivate much installation.

This suggests that like generation, there is likely a mixed solution set for storage that will be optimum, rather than any single magic-bullet techno fix. It was suggested that a homeowner might have storage batteries next to his water heater. Since energy can be stored as heat, it is likely that a partial storage solution would be a changeover from small tank and tankless hot water systems to storing energy in a big tank of hot water. This might easily act as a store that could also be used for home heating, as well as for hot water. (Conversion of the heat to electricity may be impractical at present). An insulated storage tank requires no maintenance, lasts a very long time, and seems likely to offer lower life cycle costs per joule of storage than any likely battery system. Again, not the whole solution, but part of the overall picture. Not glamorous, just cheap and effective.

A more centralized grid level storage option that similarly requires no new technology would be to build dams with a second catchment basin, or add such catchments to existing dams. The second basin need not provide the "head" that the upper dam uses for power generation, it is simply a store of water that has gone thru the dam and powerhouse. During times when power generation exceeds demand, water is pumped from the lower catchment back up to the reservoir above the dam. When demand exceeds generation, the dam releases water through the powerhouse. Water could be recycled through the dam and powerhouse any number of times without affecting the overall river flow.

cragger
12-18-2009, 12:55 PM
Do we ever want to get to a place where we are using nearly 100% renewables for power generation?

The answer is in the definition. If it isn't renewable it will eventually run out.

osmium
12-18-2009, 12:57 PM
After watching this report on rare earth extraction and processing (http://www.pbs.org/newshour/bb/asia/july-dec09/china_12-14.html) for use in alternative energy technologies, I'm wondering if research isn't green enough. Are any of these rare earth elements a part of your research, Osmium?

Thank you for the diavlog.

Thanks everyone--I know this was a snoozer unless you *really* want to know about big batteries. Natural selection and the big bang are much more interesting, but this is rubber meeting the road kind of science. :)

Baltimoron, I don't use any rare earths (http://en.wikipedia.org/wiki/Rare_earth_element), but other odd elements do come up in my work. I used to use osmium (obvs) which is a tightly regulated "middle of the periodic table" element, although not technically a rare earth. These materials are useful, so the way I see, the mining and recycling operations have to be made cleaner over time. And once we can "tag" everything made, it'll be easier to recycle things like rare earth elements with no hassle to the general public.

osmium
12-18-2009, 01:08 PM
Good discussion. I particulaly appreciated the description of the problem as being one of grid level energy storage. The types of storage you considered - chemical energy in batteries or fuel cells and possibly storage in fields using capacitors aren't the only ways to store energy, though it's understandable you concentrated on batteries since that is what you work on.

A few initial thoughts spurred by the diavlog:

Considering the relative costs of renewable sources vs. the various fossil energy sources, the crossover point seems to be approaching. Solar costs per KWH have been coming down over time, and fuels increasing in cost, particularly for oil and gas-fired plants. These appear subject to steep cost increases in the near-term future, though it will likely be a while before coal costs go up steeply. Of course in comparing the costs per KWH one must also remember that the figures are very distorted by the externalization of considerable costs from the use of fossil fuels, costs now coming home to roost though not through market economics directly tied to the causes of those costs.

A couple of additional factors in solar's favor include creation of a distributed source system that offers advantages in resiliance and robustness over a centralized source system. As a partial solution to energy generation, solar output is well matched to the demand curve. Distributed generation, such as at the home level, also gives the advantage of generation at the point of consumption, reducing both transmission needs and transmission power losses.

Completely agree. Didn't mention it, but distributing generation downward, closer to the end user, will shift the grid to an "internet" model, rather than a "broadcast" model. Making the grid more like the internet makes it more robust, more difficult to attack, etc.


A couple thoughts on storage. Though the batteries Osmium is working on are hoped to last longer than the deep discharge cells typically used in off-grid systems now (say 8-10 years rather than "several"), the installation and maintenance costs of the system of cells and attendant electronics to control charging and do power conversion still don't sound likely to be trivial. It would take a pretty steep price curve for power depending on real-time demand to motivate much installation.

This suggests that like generation, there is likely a mixed solution set for storage that will be optimum, rather than any single magic-bullet techno fix. It was suggested that a homeowner might have storage batteries next to his water heater. Since energy can be stored as heat, it is likely that a partial storage solution would be a changeover from small tank and tankless hot water systems to storing energy in a big tank of hot water. This might easily act as a store that could also be used for home heating, as well as for hot water. (Conversion of the heat to electricity may be impractical at present). An insulated storage tank requires no maintenance, lasts a very long time, and seems likely to offer lower life cycle costs per joule of storage than any likely battery system. Again, not the whole solution, but part of the overall picture. Not glamorous, just cheap and effective.

A more centralized grid level storage option that similarly requires no new technology would be to build dams with a second catchment basin, or add such catchments to existing dams. The second basin need not provide the "head" that the upper dam uses for power generation, it is simply a store of water that has gone thru the dam and powerhouse. During times when power generation exceeds demand, water is pumped from the lower catchment back up to the reservoir above the dam. When demand exceeds generation, the dam releases water through the powerhouse. Water could be recycled through the dam and powerhouse any number of times without affecting the overall river flow.

The extra plumbing, control, and balance-of-plant type stuff is why I emphasize the bigness of the battery--since the smaller the battery gets, all that stuff might not be justifiable anymore.

re: Heat. Do you work here in this building somewhere?--because you know all our talking points. :) The heat made in big power plants is mostly a waste--it goes into cooling towers or rivers. But at the local, distributed level, you could use that heat to make hot water or for home heating. Heating oil isn't cheap these days, so being able to capture power generation waste heat and store it is another big reason to change the way the grid works.

osmium
12-18-2009, 01:12 PM
Interesting.

I may have mentioned that I exist off the grid for much of the winter months. Now I happen to do so in a tent, but that tent is set up a couple hundred yards from a buddy's log cabin. His cabin is what falls right into this discussion. Also off the grid, he has a system that utilizes wind power( 1, 6ft? turbine), solar power (4 3'x6' panels) , and a gas or diesel (dependant on which one is working) generator and a rack (a 12-20?) of lead/acid batteries.

I have not done a study of it but from him I know that although things are working, he is disappointed in much of it and the generators are running quite a bit. Personal observation has me being disappointed also as his needs are seemingly small yet he seems to have to be on constant vigilant watch...and I see that rack of batteries in the basement and it just seems like one should be able to run off them for a few days without any kind of regeneration...and that is just not the case. I will do a closer study this winter...usually I am already there by now, but although its been cold, they are lacking the snow that is my draw.

He is in the midst of building a larger log cabin next to the original as his wife is expecting and while I assume he is going to hook into much of the existing I also assume he is doing some rethinking about what he has and how it could be better.

Suggestions? Should he wait a bit before investing in a bunch of new lead/acids.

Are there other materials, over and above the Zinc/Alluminum/Lithium that have promise? How available is Zinc...no shortage scenerio like you allude with lithium? (When Bolivia was mentioned, I saw scenes of Butch Cassidy and the Sundance Kid run through IRW's head (http://apollo.bloggingheads.tv/diavlogs/24630?in=16:53&out=17:15))

A side note...I worked in a coal burning power plant a couple decades ago and I remember they had a huge battery room...I can't remember the exact purpose but I would guess now it was purely for backup for lighting needs in case they themselves lost power.

Instead of preventing, can the Zinc fingers be effectively scrubbed?

That's all really cool. I think a lead-acid rack is your buddy's only option right now (someone might prove me wrong, I dunno). But that's just proof that there would be a market for such things, not only from utilities, but also from people living off the grid in logs cabins and skiing.

The zinc dendrites could be sort of scrubbed with a burst of fast, turbulent flow of the electrolyte. But then you lose them, and they're part of your stored energy. I think the only option is to figure out how to discourage their formation in the first place.

osmium
12-18-2009, 01:13 PM
Ian, I think you got the cool masking technology colors. Dude, you look like an Avatar warrior something-or-other.

osmium
12-18-2009, 01:15 PM
Did I let everyone know that in the latter part of December I celebrate a festival that includes gift giving? So my nephew will be receiving lots of electronic toys and games that are sure to run out of "juice" or battery power sooner or later.
Is it possible to have one huge battery that can run all the appliances via radio transfer of power? Will the effectiveness of the power-pack be affected by an increase in global or regional temperatures?
If I were to live off the grid, does that mean that I won't post on the internet?

I am not afraid to admit I don't fully understand radio-transmission of power. I should become educated.

osmium
12-18-2009, 01:33 PM
This seems to be the only way to make renewables work for 100% of our power generation. Even then though, it is still a good idea to have some base load power generation though that we can throttle up or down on demand right?

Do we ever want to get to a place where we are using nearly 100% renewables for power generation?

And if not, what base load options should we use?


The main ones seem to be

coal
natural gas
nuclear

And all but the last spew toxins into the atmosphere, and unfortunately, the last will always be prevented from the irrational, so what is left for base load power generation?

There probably has to be a long period where there's some fraction of renewables, for knowledge about them to get built up, and to prove they work. Work out the bugs, get people used to the idea.

look
12-18-2009, 07:16 PM
Thanks everyone--I know this was a snoozer unless you *really* want to know about big batteries. Natural selection and the big bang are much more interesting, but this is rubber meeting the road kind of science. :)

I appreciated your no-nonsense, precise teaching style. I'll bet you've taught thousands of undergrads.

look
12-18-2009, 07:50 PM
Did I let everyone know that in the latter part of December I celebrate a festival that includes gift giving? So my nephew will be receiving lots of electronic toys and games that are sure to run out of "juice" or battery power sooner or later.
Is it possible to have one huge battery that can run all the appliances via radio transfer of power? Will the effectiveness of the power-pack be affected by an increase in global or regional temperatures?
If I were to live off the grid, does that mean that I won't post on the internet?
Ah, yes, time to drag the Festivus pole out of the attic.

Whatfur
12-18-2009, 08:17 PM
I am not afraid to admit I don't fully understand radio-transmission of power. I should become educated.

Sorry osmium, but wherever I seem to travel I bring with me the possibility of attack by a rather small "Fur Troll". He is not as so much interested in any type of enlightening discussion as he is with attempting to insult me. You see, he has never quite gotten over past embarrassments nor has he been able to reciprocate, so he thinks that a constant harrassment of me is the next best thing. I feel kind of bad because there was a time when he attempted almost adult-like posts and I seem to have affected him so deeply that he now pretty much just Trolls for Fur.

I had hoped when I saw he performed the public service of providing the link here that he was taking a step in the right direction and even finding some purpose in his life, but unfortunately it was just an aberration.

But maybe we can take his post and turn it into something positive. First, it IS positive that he speaks of needing to provide gifts for his nephew and not his own children...(if you know what I mean). Second he does bring up a concept that is rather interesting although radio transference of power is certainly not the most effective means of wireless power transfer. Third, it provides me a segue to talk about almost taking a job with a company that was looking at utilizing radio waves to transmit, not power, but data to remote computers traveling around cities (of course cell phones and internet made their attempts mute and the company disappear). Glad I did not take the job. Lastly, I can answer his question...why YES I can and do access the internet from off the grid via satellite...look up the company "Wild Blue"...my buddy subscribes. I can actually log into my PC at work from off the grid, 250 miles away, and subsequently support customers around the world from a log cabin near the Canadian border. Technology is amazing. With a generator (or an effective battery) I could probably do it from my tent. However, its only amenity is a wood stove.

AemJeff
12-18-2009, 10:05 PM
Thanks everyone--I know this was a snoozer unless you *really* want to know about big batteries. Natural selection and the big bang are much more interesting, but this is rubber meeting the road kind of science. :)

Baltimoron, I don't use any rare earths (http://en.wikipedia.org/wiki/Rare_earth_element), but other odd elements do come up in my work. I used to use osmium (obvs) which is a tightly regulated "middle of the periodic table" element, although not technically a rare earth. These materials are useful, so the way I see, the mining and recycling operations have to be made cleaner over time. And once we can "tag" everything made, it'll be easier to recycle things like rare earth elements with no hassle to the general public.

This was really informative and just plain cool. I wonder about simply using gravity to for energy storage. Something like 10,000 or 100,000 gallon water tanks on stilts in a closed loop with a second tank on the ground. Use pumps to lift the water, and drive a turbine or something on the way down. Too inefficient?

Whatfur
12-18-2009, 11:03 PM
This was really informative and just plain cool. I wonder about simply using gravity to for energy storage. Something like 10,000 or 100,000 gallon water tanks on stilts in a closed loop with a second tank on the ground. Use pumps to lift the water, and drive a turbine or something on the way down. Too inefficient?

Are you not kind of describing what is already being done tapping into hydro and tidal...yet they don't need the pumps?

Personally, I have always felt that a full embrace to telecommuting by companies would have a huge impact. My company about 5 years ago moved in and took over 5 stories of a 7 story building for 400 employees or so. Probably 90% of those employees could do everything they do now from home. I am one of a small number who works about 60% from home...most drive in every day. I would say the average commute for most is at least 15 miles one way and that 15 miles on average probably takes people 25 minutes of driving. So just saying they work at least 200 days that equates to over 2 million miles traveled by people in this one company. There would be power distribution also as people would be supplying some of their own and it would be tapping multiple sources. What is currently being housed by 5 stories could be reduced to at most one thus also reducing lighting, heating, and air conditioning needs.

We have the technology. Of course some manufacturing and retailing could not tap into this but many many could.

AemJeff
12-18-2009, 11:15 PM
Are you not kind of describing what is already being done tapping into hydro and tidal...yet they don't need the pumps?
...


Yeah, but this is about storage, not production; and doesn't require a river or an ocean as an energy source. And it doesn't necessarily have to be installed on an industrial scale. A single house, or a neighborhood, could use a system like this to bank whatever transient energy sources might be available to them.

Btw, I've just been moved from 95% work at home to a mostly on site presence. Feugh.

look
12-19-2009, 08:47 AM
But maybe we can take his post and turn it into something positive. First, it IS positive that he speaks of needing to provide gifts for his nephew and not his own children...(if you know what I mean). Second he does bring up a concept that is rather interesting although radio transference of power is certainly not the most effective means of wireless power transfer. Third, it provides me a segue to talk about almost taking a job with a company that was looking at utilizing radio waves to transmit, not power, but data to remote computers traveling around cities (of course cell phones and internet made their attempts mute and the company disappear). Glad I did not take the job. Lastly, I can answer his question...why YES I can and do access the internet from off the grid via satellite...look up the company "Wild Blue"...my buddy subscribes. I can actually log into my PC at work from off the grid, 250 miles away, and subsequently support customers around the world from a log cabin near the Canadian border. Technology is amazing. With a generator (or an effective battery) I could probably do it from my tent. However, its only amenity is a wood stove.You'll do anything to get away from the in-laws, won't you?

Whatfur
12-19-2009, 09:56 AM
You'll do anything to get away from the in-laws, won't you?

;) Close though...I will do anything to get away...period. I was born in the wrong century. Actually there is a bread company around whose slogan is "100 years behind the times" that I have readily adopted.

cragger
12-19-2009, 10:15 AM
Jeff,

I also think storage using water as a potential energy source is a good idea as indicated in my comment below. There is a question of how small this scales efficiently though. There are a couple aspects of that - technical and economic. Technically, the amount of energy depends on the height and larger installations typically operate more efficiently than small ones for other factors. Probably hydraulic flow issues related to the diameter of the pipes, etc. if nothing else.

Economically, you come up against the question of dollars per joule of storage per year over the life cycle of the system. At a small scale the cost of the installation may drive toward other storage methods, and water as potential energy may be better suited for large (e.g. dams) or medium scale, community applications. Many towns have water systems, using reserviors or water towers. Combining the provision of water with operation of an energy store might mean only that the system should use the highest practical storage rather than what is probably the lowest storage (in the case of water towers) that maintains the flow. Addition of a second tank or catchment below the tower or reservoir would allow recycling of water beyond the supply flow to make the energy storage function work better of course.

Just what scale is efficient and how it compares to other energy stores would make a nice little study. Ideally one that somebody could cage a way to get paid to do. Maybe you or someone else here works in a location that hires coop students or has other contact with an academic community and it would work as a student project.

osmium
12-19-2009, 10:45 AM
Yeah, but this is about storage, not production; and doesn't require a river or an ocean as an energy source. And it doesn't necessarily have to be installed on an industrial scale. A single house, or a neighborhood, could use a system like this to bank whatever transient energy sources might be available to them.

Btw, I've just been moved from 95% work at home to a mostly on site presence. Feugh.

Re: gravity and water as energy storage: Yes people do it, but I think it is necessarily a large project. Dinorwig power station's wikipedia entry is an interesting read (http://en.wikipedia.org/wiki/Dinorwig_Power_Station). I'll look around for more examples. I remember a friend of mine telling me about this being done recently, but I don't remember the location.

look
12-20-2009, 12:47 AM
;) Close though...I will do anything to get away...period. I was born in the wrong century. Actually there is a bread company around whose slogan is "100 years behind the times" that I have readily adopted.Me, too.

Whatfur
12-20-2009, 09:12 AM
Re: gravity and water as energy storage: Yes people do it, but I think it is necessarily a large project. Dinorwig power station's wikipedia entry is an interesting read (http://en.wikipedia.org/wiki/Dinorwig_Power_Station). I'll look around for more examples. I remember a friend of mine telling me about this being done recently, but I don't remember the location.

This IS cool and the use of the caverns inside the mountain to hide the workings is amazing...but it proved to validate my first feeling when I read Jeff's proposal...that it would take more energy to raise the water than it would produce by its lowering. Sure costs of such can be offset by time management but seems to still be a bit counter-productive to overall goals.

I guess the same can be said about batteries right??...if it takes 10 mw to store/charge 8 mw which it turn becomes 6mw of usable energy we only gain something if the energy was going to be lost or shed in the first place. Unless we are talking $$$ where 6mw during the day may be >= 10mw at off-peak. (My numbers are guesses...osmium might have some actual)

osmium
12-20-2009, 11:08 AM
This IS cool and the use of the caverns inside the mountain to hide the workings is amazing...but it proved to validate my first feeling when I read Jeff's proposal...that it would take more energy to raise the water than it would produce by its lowering. Sure costs of such can be offset by time management but seems to still be a bit counter-productive to overall goals.

I guess the same can be said about batteries right??...if it takes 10 mw to store/charge 8 mw which it turn becomes 6mw of usable energy we only gain something if the energy was going to be lost or shed in the first place. Unless we are talking $$$ where 6mw during the day may be >= 10mw at off-peak. (My numbers are guesses...osmium might have some actual)

yeah, that's the general idea. You're always going to get less energy out than you put in, but the considerations are efficiencies and costs (both $$ and environmental, which in a perfectly operating market would be equivalent). Batteries can be 90% efficient, fuel cells can be 60% (reversible cycle with hydrogen), and turbines with fossil will be something less than 40%. But fossil fuel stuff is cheapest due to 100 years of optimization and the relative ease that you just take it out of the ground.

For pumped hydro storage (I am not an expert, but this is my impression), it won't scale down very far in size. I think you need a lot of gravity behind water to get that kind of power back out of it, so you essentially need a mountain. (But if you happen to own a mountain already, I bet it's pretty cheap.) Batteries, fuel cells, and turbines can all probably work on a scale small enough to distribute them fairly evenly through a city, and if one breaks, then the others can bring up the slack, much like the internet.

I don't know the numbers either, Whatfur, but those ones you give in your last sentence capture the idea.

osmium
12-20-2009, 11:10 AM
I appreciated your no-nonsense, precise teaching style. I'll bet you've taught thousands of undergrads.

Thanks, that means a lot to me, because that's the way I want to be. :) Not thousands, no, but maybe a few hundred over the years. I'm a research associate, not a professor, so I haven't had much chance to develop my own classes yet. Maybe soon, who knows.

AemJeff
12-20-2009, 01:34 PM
yeah, that's the general idea. You're always going to get less energy out than you put in, but the considerations are efficiencies and costs (both $$ and environmental, which in a perfectly operating market would be equivalent). Batteries can be 90% efficient, fuel cells can be 60% (reversible cycle with hydrogen), and turbines with fossil will be something less than 40%. But fossil fuel stuff is cheapest due to 100 years of optimization and the relative ease that you just take it out of the ground.

For pumped hydro storage (I am not an expert, but this is my impression), it won't scale down very far in size. I think you need a lot of gravity behind water to get that kind of power back out of it, so you essentially need a mountain. (But if you happen to own a mountain already, I bet it's pretty cheap.) Batteries, fuel cells, and turbines can all probably work on a scale small enough to distribute them fairly evenly through a city, and if one breaks, then the others can bring up the slack, much like the internet.

I don't know the numbers either, Whatfur, but those ones you give in your last sentence capture the idea.

I haven't totally given up the idea that smaller scales might be workable. The 75% efficiency achieved at Dinorwig surprised me. I have no idea how to quantify the amount of power that could be generated by a water tower size pair of tanks - but, if you powered the pumps with combination of solar and wind, e.g., the cost of storage seems pretty reasonable. If it's possible to generate useful power on that scale, then there might be the germ of a workable idea here. That said, I hear what you're saying.

Flaw
12-20-2009, 10:22 PM
I'm a fan of osmium and irw.

JonIrenicus
12-20-2009, 10:37 PM
Here is an old article from 1990 that seems to talk about some of the issues with zinc batteries.

http://www.lbl.gov/Science-Articles/Archive/battery-development-at-lbl.html


I wonder what mentioned there has been solved, and what has not. I guess the dendrites are still a big issue, is that the only big hurdle left?

osmium
12-20-2009, 11:34 PM
Here is an old article from 1990 that seems to talk about some of the issues with zinc batteries.

http://www.lbl.gov/Science-Articles/Archive/battery-development-at-lbl.html


I wonder what mentioned there has been solved, and what has not. I guess the dendrites are still a big issue, is that the only big hurdle left?

That's a pretty awesome article. You know, I work with a couple people from the Cairns lab, and there is a huge review paper on zinc batteries by Cairns and McLarnon that I used to learn my head from my ass when I started working on Zn batteries. I allude to it in the diavlog briefly, but I think a major shift in funding priorities effectively ended their research in the early 90s, and we are one of the first labs to pick up Zn batteries again after all those years. It's deep in the weeds, but our design is a flow battery that's a bit different than theirs. A friend of mine says if I want to ask Cairns any questions I can, but I'm holding off till I feel like I've taught myself as much as I can and made a couple advances myself. Dendrites are still the issue! But not a lot has been done since then. The world went lithium for 2 decades, seriously.

Cool! Thanks for the link.

Whatfur
12-21-2009, 04:08 PM
One thing lithium seems to have an advantage with is ability to keep its charge in cold weather.

How does Zinc do?

graz
12-31-2009, 09:01 PM
How does Zinc do?

Very well, thank you. (http://www.youtube.com/watch?v=lLp4DZmPqYE)

Starwatcher162536
01-02-2010, 06:44 PM
I don't have a problem with co-generation, but if the emissions are cooled to near ambient levels, convection won't occur and the emissions could become a local nuisance.

Are there industry standards for minimum heat levels for various emission types to make sure the emissions meet minimum dispersion requirements?

Starwatcher162536
01-02-2010, 06:45 PM
Is this diavlog still up? Whenever I click on the orange "View Diavlog" link, I just get a blank page with:


{/exp:weblog:entries}

bjkeefe
01-02-2010, 06:58 PM
Is this diavlog still up? Whenever I click on the orange "View Diavlog" link, I just get a blank page with:


{/exp:weblog:entries}

That's a bug with all Apollo diavlogs. For this one specifically, go here (http://apollo.bloggingheads.tv/diavlogs/24630). In general, the way to get to a given Apollo diavlog from its associated thread page is to added apollo. to the URL; e.g., in this case, you want to visit

http://apollo.bloggingheads.tv/diavlogs/24630

while the "View Dialog" link points to

http://bloggingheads.tv/diavlogs/24630

So, the kludgy way to get to the Apollo diavlog is to click the "View Diavlog" link and then modify the URL in your browser's location bar.

P.S. All Apollo diavlogs are listed and linked to in the sidebar of the page at http://apollo.bloggingheads.tv/diavlogs/.

Whatfur
01-04-2010, 09:57 PM
Very well, thank you. (http://www.youtube.com/watch?v=lLp4DZmPqYE)

That was funny...but shouldn't you have been out with your friends at the time you posted it?

popcorn_karate
01-05-2010, 04:17 PM
I haven't totally given up the idea that smaller scales might be workable. The 75% efficiency achieved at Dinorwig surprised me. I have no idea how to quantify the amount of power that could be generated by a water tower size pair of tanks - but, if you powered the pumps with combination of solar and wind, e.g., the cost of storage seems pretty reasonable. If it's possible to generate useful power on that scale, then there might be the germ of a workable idea here. That said, I hear what you're saying.

i loved this idea for a while (water battery) but i do think you would need some good topography to make it work.

15 feet of head
10,000 gallon tank of water
5 cfs
= 3.5 kw for 5 minutes

head(ft) * cfs * efficiency (0.55 for a good system) * 0.085 = kw

1cfs = 448 gallons/minute

the only way to make it really work is to have something closer to 200 feet of head.

cragger
01-06-2010, 02:39 PM
The energy is dependant on the head, but that is not the only variable. There are many dams, including one near me, that don't have anywhere near 200 feet of head. More is good, but not necessary. Note that in your example, a 10k gallon tank is only about a 10 foot cube. It's not a lot of water for this application, though your figures do support your overall point, with which I agree, that the technique doesn't scale well down to individual home use.

On the other hand, playing with the numbers a bit you can see the merits of the approach. Even on a home level,

3.5 kW x (1/12 hr) x 30 (days/month) ~ 8.75 kWh.

so if one had for example a slightly bigger tank, 15' cube ~25k gallons, you would get nearly 22 kWh/month. Still obviously not a lot of energy, but for certain isolated applications that might be enough to say, keep the refrigerator and freezer running overnight and allow for some nightime lighting if one used solar/wind to fill the tank and did energy demanding activities during the daytime (assuming solar generation). Scaling up a bit more by considering a water store the size of a backyard swimming pool, and you now may have something pretty decent.

There is of course an advantage if you have even a modest topographic aid here. If you have a 20 or 25 foot slope to work with, one could use something like swimming pools for the store - i.e. the dig a hole and drop in a liner type pool, for cost reasons. This would save you having to build a big strong tower and buy steel tanks. It's not hard to picture a system that would store 100 kWh or more per month, probably enough for most home users without worrying too much about being careful about usage.

Without costing out systems, I suspect cost efficiency is one limiting factor in doing this at the individual home scale, though again of course not necessarily the only problem for those on flat, 1/4 acre lots in the local subdivision. I also wonder about the efficiency factor of the energy recovery turbine. At a home use level, one would generally want to draw power at a pretty low rate, well below the 3.5 kw figure you used, and I suspect that there is a minimum flow rate that is required for any given turbine to reach its theoretical efficiency rating. Batteries being expensive and of limited service life, perhaps some hybrid system involving a smaller battery store augmented by a water-based potential energy store would be best, reducing both the dynamic range of efficient output required for the hydro system and the number, size, and attendant cost of the batteries.

All a somewhat long winded way that while one doesn't want to dismiss this out of hand as an option for some users, the method seems better suited in general for larger scale applications at the community level and above.

popcorn_karate
01-06-2010, 05:11 PM
The energy is dependant on the head, but that is not the only variable. There are many dams, including one near me, that don't have anywhere near 200 feet of head. More is good, but not necessary. Note that in your example, a 10k gallon tank is only about a 10 foot cube. It's not a lot of water for this application,

here's a 10k tank you can buy - check out the dimensions and price.

Part Number: T10000IW
Capacity: 10000 Gallons
Size: 141"D x 160"H
Weight: 1803 lbs.
Ships From: CA, AL

(oops - $2400.00 is the price)

so, you would be elevating 82,000 pounds. by the time you build something to support that amount of weight and buy the tank - you are already deep in a financial hole that will probably never be filled.




3.5 kW x (1/12 hr) x 30 (days/month) ~ 8.75 kWh.

given the assumptions in the original calculation, you would need a 180,000 gallon tank - the cost of the tank would price you out before you tried to elevate it.



All a somewhat long winded way that while one doesn't want to dismiss this out of hand as an option for some users, the method seems better suited in general for larger scale applications at the community level and above.

or someone with significant topography on their property. you could build a holding pond, skipping the expense of a tank, and use the topography for the head, avoiding the need for a tower.

i was totally stoked on this idea for about 6 months before doing the calculations and realizing i really needed to get onto another idea, at least in my location.

cragger
01-06-2010, 06:21 PM
You miss the point of the "x 30 days" in the calculation. Using the example of solar generation, you would re-fill the upper water store every day using solar power. You need to store enough energy to get you through to the next generation period, not build up a month's-long store at once. Looking at things on a month long scale just seemed to be useful since we typically get electric bills on a monthly basis, so there is a little "feel" to that sort of timescale.

This neglects extended periods of bad weather/no wind or whatever of course, just back-of-the-envelope stuff that shows theoretical potential, though not necessarily at a $/kWh cost that is attractive. On the other hand, a large energy store using current deep discharge batteries isn't what you would call cheap either.

This leads to the point Osmium was alluding to in looking at this as a grid-level question. Like many things, a cooperative approach is likely the most efficient. I favor a hybrid system, with millions of small points of power generation going down to the home level, combined with large generation sources on the grid as well - dams, wind farms, wave power, etc. once the inevitable transition to renawables happens. I would envision the majority of storage for load leveling would be at scales above the home.

Afterthought: one readily sees that combining the functions of conventional dams with the addition of recycling of water as energy stores provides obvious synergy as a very efficient partial solution.

popcorn_karate
01-07-2010, 05:04 PM
You miss the point of the "x 30 days" in the calculation.

or perhaps you missed that you would need a 180,000 gallon tank to run it for 1.5 hours each day of the month as you suggested?


Using the example of solar generation, you would re-fill the upper water store every day using solar power. You need to store enough energy to get you through to the next generation period, not build up a month's-long store at once. Looking at things on a month long scale just seemed to be useful since we typically get electric bills on a monthly basis, so there is a little "feel" to that sort of timescale.

This neglects extended periods of bad weather/no wind or whatever of course, just back-of-the-envelope stuff that shows theoretical potential, though not necessarily at a $/kWh cost that is attractive. On the other hand, a large energy store using current deep discharge batteries isn't what you would call cheap either.

This leads to the point Osmium was alluding to in looking at this as a grid-level question. Like many things, a cooperative approach is likely the most efficient. I favor a hybrid system, with millions of small points of power generation going down to the home level, combined with large generation sources on the grid as well - dams, wind farms, wave power, etc. once the inevitable transition to renawables happens. I would envision the majority of storage for load leveling would be at scales above the home.

Afterthought: one readily sees that combining the functions of conventional dams with the addition of recycling of water as energy stores provides obvious synergy as a very efficient partial solution.

agree with this stuff. distributed energy generation and storage is where we need to be going.

cragger
01-07-2010, 08:27 PM
or perhaps you missed that you would need a 180,000 gallon tank to run it for 1.5 hours each day of the month as you suggested?

Perhaps. From your BOE calculations, the 10k gallon tank delivers:

3.5 kW for 5 min - close enough for BOE for sure

3.5 kW x 5 min /60 min/hr = .2916667 kWh/day reflecting the energy recovered each time you run the upper tank through the generator.

.291666. kWh/day x 30 d/mo = 8.75 kWh/mo

for the 10k gallon tank you suggested. Perhaps you are referring to my suggestion that with a slightly greater head, and a larger water store one could easily envision a home system with a storage capacity in the neighborhood of 100 kWh/mo?

100/8.75 ~ 11.4

suggesting you need a bit more than an order of magnitude increase in head, gallons of storage, or some combination thereof. i.e gallons x N and head x P with N x P ~ 11.4 < the factor of 18 as you suggest. (i.e. 1.5 hours/day = 90 min at 5 cfs = 18 x 5 min) , presumably how you got to the 180k gallons figure). As I recall I suggested that a combination of a modest increase in head (20' vs. 15' gives a factor of 4/3, and a larger water store such as swimming pool size: 11.4 x 3/4 x 10k gallons ~ 85.5k gallons for example). Or bump the head up to 25 feet. So on.

Now my algebra and ability to click the right buttons on Microsoft's calculator are both always suspect so please feel free to expound in greater detail on what error I am making here. Lacking such, we could pretend to be physicists who, being within an octave let alone an order of magnitude, could consider ourselves to be in agreement that the technique seems applicable, but of questionable economic efficiency at the household scale outside of specific users with strong economic motivations and/or situations likely including topographic advantage in reducing implementation cost. On the other hand, a technique of such efficiency at larger scales that we are a rather sad and stupid bunch if we fail to use it collectively at the grid-level scale.