Long-Term, Safe, and Reusable Batteries

I just watched this video posted by Geoff Lawton



Guys, I'm confused by this. I was planning to get lithium for my system, now it seems its actually quite bad. I dont get, aren't lithium batteries suppose to have more cycles than lead-acid?

Nickel-Iron sound great, too bad you cant find them anywhere (not where I live, at least)

If you want a long lasting battery and are willing to maintain it regularly, then Nick-Iron is probably the best one.
Looks like you can get them from the Kursk Battery plant.

Because a battery is classed as better at performance doesn't mean it's better for the environment.

Like everything in the RE world; it depends. Notice in the video when they talk about longevity of nickel iron batteries they are only showing you the original Edison batteries from 60 ish years ago. .. the current version of the nickel iron are made in Russia and china. In the us you would contact iron Edison or elsewhere probably through alibaba direct from the manufacturer. They do have problems though. They boil off a lot of water so produce more h2 then lead acid. They have greater internal resistance then lead acid so "loose"more of their energy then lead. They are expensive usually 3 times the cost...
In terms of embedded energy lead is common easy to manufacture and fully recyclable. Nickel is harder to mine and manufacture but will last longer. Lead is still the norm in the solar world. Nickel is probably a better option if you can afford a battery bank as large as the lead equivalent. Due to price the sales tactic for nickel is to say you can undersized it since it lasts longer... that is a mistake. Nickel does have a finite life it's just longer. Push an undersized nickel  bank too hard and it will wear out faster.
Lithium iron phosphate has potential but is currently not recycled due to low volumes and problems  in its composite nature. It's real advantage comes in its ability to take a huge inrush of current in a short time.
They all have strong points and weaknesses.
Hope that helps somewhat and does not make it worse.
Cheers,  David B

If you plan to buy batteries in the short term, and money matters, then lead acid is probably the best bang for the buck. It would be great if the nickel iron batteries become more competitive in the next 5 years, since I'll be looking to buy batteries in 5-6 years    

While we may make plans that we will be doing something for the next 20 years, it's pretty rare for that to be the case. But I think if you can afford nick-iron with that time frame, you would probably come out ahead vs LA.

thank you all for the comments.

I was planning to get this new BYD lithium batteries, which have a very convenient "box" to store them and allow for easy expansion.
My plan was to get just one 2.5kw module and expand later (if needed, because I dont really use that much electricity and we have lots of sun here). Considering that I can discharge it up to 90% vs 50% for lead-acid, I dont think the price difference is THAT significant(around 1000€), having in consideration the longer battery life and convenience of lithium.

makes sense?

So This is one of those sales techniques I mentioned. While lithium can be discharged to the 90 percent level you should avoid it. For lithium you can get EITHER 10000 cycles OR really deep discharge rates. The claims are mutually exclusive. I'm not familiar with the bank you quoted but at 90 percent discharge most of the lithium iron phosphate packs will last 1500 cycles. Ask your supplier to provide a cycle versus depth of discharge table. It is a standard industry measure and should be available to him... In the lithium world I like the blue ion system myself. Their cells have 10 years of test data behind them...
Cheers,  David B.

David Baillie wrote:So This is one of those sales techniques I mentioned. While lithium can be discharged to the 90 percent level you should avoid it. For lithium you can get EITHER 10000 cycles OR really deep discharge rates. The claims are mutually exclusive. I'm not familiar with the bank you quoted but at 90 percent discharge most of the lithium iron phosphate packs will last 1500 cycles. Ask your supplier to provide a cycle versus depth of discharge table. It is a standard industry measure and should be available to him... In the lithium world I like the blue ion system myself. Their cells have 10 years of test data behind them...
Cheers,  David B.

this is the datasheet I have access to: http://www.windandsun.co.uk/media/943876/BYD-B-Box-LV-Datasheet.pdf
doesn't seem to state a lot ... there's a round trip efficiency of 95%. In the shop where I got this info, they told me the 90% value was considering a 6000-cycles life. While a lead-acid was rated at 50% with 1400 cycles. thats a significant difference...

Nuno Donato wrote:

David Baillie wrote:So This is one of those sales techniques I mentioned. While lithium can be discharged to the 90 percent level you should avoid it. For lithium you can get EITHER 10000 cycles OR really deep discharge rates. The claims are mutually exclusive. I'm not familiar with the bank you quoted but at 90 percent discharge most of the lithium iron phosphate packs will last 1500 cycles. Ask your supplier to provide a cycle versus depth of discharge table. It is a standard industry measure and should be available to him... In the lithium world I like the blue ion system myself. Their cells have 10 years of test data behind them...
Cheers,  David B.

this is the datasheet I have access to: http://www.windandsun.co.uk/media/943876/BYD-B-Box-LV-Datasheet.pdf
doesn't seem to state a lot ... there's a round trip efficiency of 95%. In the shop where I got this info, they told me the 90% value was considering a 6000-cycles life. While a lead-acid was rated at 50% with 1400 cycles. thats a significant difference...

Well... I don't want to be a naysayer. The charts I have seen show the values I quoted based on the iron phosphate cells most commonly used. The data sheet does not tell you the depth of discharge they used to achieve that result of 95 percent efficiency and 6000 cycles isn't mentioned anywhere. If you read the bottom of the sheet it does mention that to achieve the 95 percent efficiency rating they used a charge rate of .5 C . That is not a realistic test for an off grid battery a c10 rate of charge would increase the lead acid battery's efficiency up the the 80 percent range and is more common for charging. Batteries are kind of the wild west. Everyone has different numbers they throw around and it gets really confusing. The website looks good. maybe do some searches for reviews online not affiliated with the sellers site? Whichever system you choose try to size it in the 30 -50 percent per day range to give you ample reserve and long life. I wish you good luck.
Cheers,  David

My thought is to buy used EV battery packs.  The environmental cost has already been paid so there is no additional cost to reuse them as a house battery.

EV batteries might still have a lot of life left in them, but are replaced because they no longer provide the range required, or they are available because the original vehicle was wrecked, etc.

Even an EV battery with half it's useful life used up will have better performance and efficiency than a brand new Lead-Acid or Nickle-Iron battery (MUCH better efficiency than a Nickle Iron), and it will likely outlast the Lead-Acid battery pack.

Can I suggest the most renewable form of energy is photosynthesis via tree leaves and the most ethical batteries are the resulting wood. Billions going into solar panel rollouts and they have their place in the diversified solution, but just imagine if the same investment and manpower went into planting trees.

Peter VanDerWal wrote:My thought is to buy used EV battery packs.  .......
EV batteries might still have a lot of life left in them, but are replaced because they no longer provide the range required, or they are available because the original vehicle was wrecked, etc.

Peter, as the EV market is relatively new, is there a common source for these jettisoned batteries.....do they go to wrecking yards or are they relocated to some other distributor?  Thanks!

Peter VanDerWal wrote:My thought is to buy used EV battery packs.  

These are 18650 cells put together in series to add up to hundreds of volts. One fails and a hundred cells are seen as duff. The powerwall has some intelligence and switching to isolate bad cells but still suffers from this phenomena. So yes you can have an EV with a "dead" battery but lots of redeemable cells. These cells are amongst the highest quality 18650s you can find. But you are not just going to get a battery pack in a usable form, there will be ripping apart off enclosures and soldering and you will end up with something that has been separated from its charging circuitry which then gives you quite a fire risk.

Yeah. Personally, I dispense with convenience for a better performing product that will last longer, and one that's fully recyclable in current infrastructure.

The only reason to need a lithium-ion battery is portability, in my view. That's why they are used in everything from phones to laptops and tablets, to electric cars.

But a bank of batteries for a solar array only needs to be as mobile as the array itself, which is to say, not really, at all.

When the dust settles, I hope that we find we have a reliable, completely recyclable battery system, comprised completely of commonly-found and easily, cleanly-sourced raw materials, with an energy density and recharge rate comparable to that of gasoline in internal combustion engines. It will likely be less battery and more supercapacitor, in all likelihood, but whatever.

Sorry, Nuno, but it sounds like the battery guys you're talking to are trying to sell you on something you don't really need, and that won't do for you what you want, at least not as well as a cheaper, bulkier, lead-acid battery bank. I wouldn't trust a data sheet that doesn't conform to industry standard, and doesn't include basic information.

-CK

EDIT: I forgot about the ethical component. I wouldn't consider it ethical to use lithium at all, in the current socio-political environment. Where is all that lithium coming from, China? How well are they caring for the earth in the course of mining, and in disposal of waste products, both of manufacturing, and at the end of the product's life? In addition, there are many operations that are producing what will likely be termed "conflict lithium," either for reasons of questionable compensation and damages to property owners, or for reasons of "eminent domain," or whatever authoritarian dictatorships call such things. If there was a cheap, local alternative, I would choose that, and not touch lithium again.

Steve Farmer wrote:

Peter VanDerWal wrote:My thought is to buy used EV battery packs.  

These are 18650 cells put together in series to add up to hundreds of volts. One fails and a hundred cells are seen as duff.

Only Tesla uses 18650 batteries in their EVs.  All of the other companies use MUCH larger cells in their EVs.  

The Chevy Volt, for example, used 288 batteries (each weighing almost 2 lbs) in the first generation Volts, and fewer, heavier, batteries in the current generation.
The Nissan Leaf uses cells that weigh about 2.5 lbs each.

I'm not sure about Teslas, but with all the others it's relatively simple to replace a single cell, so one bad cell won't get the whole pack replaced.

Most of the used packs that are available now are from wrecked EVs.  In the near future I expect to start seeing used packs available because they no longer have enough range left in them.  This is especially true of the early model Leaf's because they didn't do anything to prevent 100% discharges so many of them already have less than 1/2 their original range.

I think the best packs to look for are ones that came from a wrecked Volt.  The battery management system on them never allows the battery to be fully charged or fully discharged which greatly increases their lifespan.

Chris Kott wrote:
EDIT: I forgot about the ethical component. I wouldn't consider it ethical to use lithium at all, in the current socio-political environment. Where is all that lithium coming from, China? How well are they caring for the earth in the course of mining, and in disposal of waste products, both of manufacturing, and at the end of the product's life? In addition, there are many operations that are producing what will likely be termed "conflict lithium," either for reasons of questionable compensation and damages to property owners, or for reasons of "eminent domain," or whatever authoritarian dictatorships call such things. If there was a cheap, local alternative, I would choose that, and not touch lithium again.

Actually the biggest lithium mines are in Australia, Chile and Argentina.  Combined they produce about 80% of all lithium.  Australia alone produces almost 1/2 of that.

China only has some very small mines, but they were smart enough to BUY most of the other available mines (and various other rare mineral mines)

Mining lithium generally has very little impact on the environment.  Lithium is typically found in salt flats and brine pools, "mining" it mostly involves scraping it up off the ground, or separating it from the brine.

I've been dying to ask this  but the thread is a tad young. Ethically sourced batteries can be construed to mean many different aspects .

Here goes.. I live in Great Britain so things might be a bit different to what is in place in the USA.

I have an on grid solar PV system . it's been very good to us paying for itself in about 4 years instead of the estimated 6 years .

Going through our production figures and the data available on the internet for the average output of such set up in the area it seems we are 18%  above the average output …

I've put this down to the adjacent bungalow's ( four feet higher up the hill than us )  large white wall and 30 degree sloping roof some 30 feet away, thus it's reflecting a lot of UV/sunlight back on to our panels .  There are also two 8 x 4 foot double glazed windows in that wall, when it's getting sun..07.00 till 1530 the yard between us is blindingly bright and very hot in our  side of the fence .  So I'm also guessing our panels are sort of preheated to maximum efficiency .

We have been running an Outlander PHEV for four years using excess day production for day recharging or low cost metered night rate company electricity on a time clock to top things up from 0200 till 06.00 hrs.

It works well , has dropped our transport costs to a few gallon per six months instead of a tank of fuel every ten days  . Adjusting all figures to take all modes of fuel into account means we are way ahead/ in pocket than the paid for in " four years" statement already mentioned above.

OK that's the set up .
For quite a while I've been interested in the possible addition of a rechargeable battery bank that will have some serious storage and at nearly 70 yrs old don't really want to try and install or maintain I myself as I'm also 80 % crippled.  They have only comparatively recently been allowed to be installed on the British electricity grid system plus they are slightly different to the USA's way of being wired up internally and externally.

One of the systems I looked in to is the Tesla power wall .. seems  it has now ben stated that the cycling rate is almost infinite .. so could well extend to more then 30 years ( that would most certainly see me  off this mortal coil  ) .

At first this seemed a bit far fetched.. then I remembered that the website for the Outlander has recently been added to , changed to state the Outlander PHEV drive battery is now warranteed for 10years ( didn't give an  ..at what percentage efficiency figure though ).

From my engineering apprenticeship days , doing things like engine development and component testing to destruction I realised that for a big company to be able to put that out in their sales literature the battery will have been tested to at least double the proffered warrantee to get a safe set of numbers that are not likely to be called to account if things fail .
I have two original Japanese made Makita  rechargeable hammer drill  batteries that are almost forty years old and still  take a decent charge to give me 25 minutes 20 x 8 mm concrete drilled holes from each battery so that kind of helps a bit,  but does not reflect the true picture.

Indeed it was put to me that Elon Musk would personally hop on his jet complete with installation team and bring a new battery to me if mine failed .. are the reliability figures really that good ?


So , I guess what I'm looking for is some sensible technically orientated views as to the sense in using one of the Tesla Powerwall's as my power store, that may / may not last 30 or more years.
I'm not really interested in the merits of one sort of battery compared to another as all are polluting to a fair degree . I'm looking for fit for purpose effectiveness instead .

Thanks
Dave  

Aquion energy salt water batteries are cradle to cradle certified and made of none toxic materials.
They can be fully discharged and left like that for months, they don't burn and should last a long time.
I have them for over 2 years and very happy with them....

As we all know that coin has two faces; similarly, whatever type of battery you choose, each will have some advantages and disadvantages. Before you choose a battery, you need to decide some parameters that can help you to make the right decision like how much you want to spend, do you want to take hassle of maintenance, do you need an eco-friendly battery or not, what is your daily usage, which brand do you prefer for your battery, etc. Once you know these parameters, you can easily choose the best one.
However, I have made a research where I found some benefits of lithium-ion batteries and lead-acid batteries. Here are some reasons to choose lithium-ion batteries and lead acid batteries:
Lithium-Ion battery:
• require low maintenance
• have high energy density
• can store more amount of energy in less amount of lithium
• consume less space as compared to others
• do not leak, hence they are safe
• have less charging time as compared to others.
Lead-Acid batteries are:
• able to withstand frequent discharging.
• cheaper than other kinds of batteries.
• more rugged durability.
• able to deliver more consistent performance than other batteries.
During my research, I have found that lead-acid batteries are best for an electrical storage in off-grid energy systems, whereas, lithium-ion batteries are best for the solar panels. So, you can make your decision according to the type of energy system you have on your premises. If you need some more information about which battery storage is best, then check out this blog: https://www.sunpowersource.com/best-battery-storage-for-solar-panels/

I tried to find out more about those salt water batteries .

It seems that the only company who made them went through a chapter 11 bankruptcy sometime in June / July 2017 .
I'm not very encouraged by the info I found on line that says they will be coming back like the proverbial Phoenix & that the batteries need further development & redesigning . Nor  the knowledge that a Chinese company has  purchased the company.
Think I'll give it a miss for a decade or so .

Steve Farmer wrote:

Peter VanDerWal wrote:My thought is to buy used EV battery packs.  

These are 18650 cells put together in series to add up to hundreds of volts. One fails and a hundred cells are seen as duff. The powerwall has some intelligence and switching to isolate bad cells but still suffers from this phenomena. So yes you can have an EV with a "dead" battery but lots of redeemable cells. These cells are amongst the highest quality 18650s you can find. But you are not just going to get a battery pack in a usable form, there will be ripping apart off enclosures and soldering and you will end up with something that has been separated from its charging circuitry which then gives you quite a fire risk.

Reportedly, there are quite a few electric vehicle batteries to be had through the v yards. BMS can be intact and/ or made to operate as safely as in the car.

Safer really, the charge and discharge rates are much lower in battery based residential power systems. The articles have great informaton, and i look forward to reading them when they come out.

Here are some links to salvage batteries. I think nissan leaf batteries are also available.

http://evtv.me/2018/06/100kwh-tesla-power-wall-on-steroids-the-powersafe-100/

http://store.evtv.me/proddetail.php?prod=TeslaBattModule

I have had solar with battery back up for over 20 years, my panels, inverter and charge controller are 21 years old.  A few years ago, I needed to replace my small battery bank and looked into the options.

I didnt want lithium ion for home energy storage here.  Lithium ion has issues like mining the lithium, fire danger ( I have been evacuated twice for woldfire) and it likes a certain temperature range, likely in my location I would need to run a fan on it all summer, and they are expensive.  The advantage of lithium-ion being lightweight and less volume is important for mobile uses, like cars and cell phones and laptops, for stationary use we dont need lightweight.

Other options were to get another set of Trojan lead acid, and these are fine, and the lead cores are recycled and I already had a battery box and cables that would work.  I would like longer life though.

I looked into Iron Edison, these look like a good battery for home use, and people change the electrolyte and they go forever ( or at least a very longer time)

Then I came across the most environmental or ethical home use batteries I have seen (they are not in production right now, but they say they will be again) and I bought a few 3 years ago, Aquion. The criteria when they were developed was to only use plentiful and inexpensive raw materials so that we wouldn't be constrained to make alot of them.  The 2 materials for anode cathode are one is carbon and the other is manganese , the electrolyte is salt water, the material separating the plates is cloth and is the part that wears out.  There is no instructions, so no way to do it, but as far as the technology goes, you should be able to unstack the cells and rebuild ( although the company never planned on this) maybe not at home, maybe in a shop, but totally an easy to rebuild system if any society is ever interested in such.  The cells are in plastic cases that stack, so that one battery has a footprint of 1ft by 1ft and they are each, I dont want to go measure, 3ft tall or less. Each battery is 48 volt, I think they also sold some that were 24Volt, the stack was just half as many cells and shorter.  I have a 48volt solar system so getting 48 volt batteries worked out.  I have been very happy with them, just wish I had bought another one, I only have 3.  Ran everything off them when the power was out in Feb.for 3 days, but I was being too carefree with the power, did ALOT of hours of recreational use, house stereo on loud, used my electric appliances like the refrigerator, toaster and electric kettle, and I left the house pressure pump circuit on, this used to be ok, but I forget I have a small 2nd unit here now.  Next long outage I will switch off the pressure pump, the water tank is uphill enough, just takes longer to fill up stuff and no showers.  Or not use the big stereo....  The other advantage of the Aquion batteries is that they can be run down to zero without doing any damage.  http://aquionenergy.com/technology/deep-cycle-battery/

Its interesting to get feedback from an aquion owner. My understanding is after they declared bankruptcy the whole production facility was bought and transferred to China. They have advantages as mentioned, but some drawbacks. They do take up a lot of floorspace for the amount of energy they store and have a low rate of charge and discharge so maybe not great for large solar arrays or high draw situation unless you have many strings to pull from. Total lifespan in the real world is still unknown.
Cheers,   David

The property I bought recently has Aquion batteries. I also have a module of backup batteries, so hopefully I won't need new ones for years. All of the solar equipment and two of the generators on this property are stored in a detached two car garage that we call the solar building. i am slowly learning all the systems, including the solar on the property. Glad to know that the batteries are not terrible for the environment. My understanding of one of the big advantages is that they don't require an equalization charge, they are virtually maintenance free.

David Baillie wrote:Its interesting to get feedback from an aquion owner. My understanding is after they declared bankruptcy the whole production facility was bought and transferred to China. They have advantages as mentioned, but some drawbacks. They do take up a lot of floorspace for the amount of energy they store and have a low rate of charge and discharge so maybe not great for large solar arrays or high draw situation unless you have many strings to pull from. Total lifespan in the real world is still unknown.
Cheers,   David

yes you do not get alot of amps at once, but plenty to start up eiher of my pumps and my well is at 220ft.  floorspace is not more, overall cu ft is more as they are taller.  The height is a good height, I am going to make a table top on the top of mine so the space will be more useful than when I had the Trojans, the shorter batteries.  The batter box for the Trojans would gt stuff put on top inevitably, and hten You would need to  open it to do maintanance.  The Aquions do not need any maintanance.  I only have 3 in parallel, but I do think idealy 4 in parallel would be better ( the more in parallel the more amps) but, I have not seen a problem with just the 3, maybe a very slight light flicker in the house for part of a second when a water pump starts up, barely noticable, so 3 work fine.  I run a full house on this

Ex-telecommunication batteries can be a good choice, if you can find them. Over here, the telephone companies use sealed lead acid ones for backup in case of grid failure, and often they've hardly been cycled at all, but they just replace them after they've been sitting there for a certain number of years, so it is possible to get perfectly good batteries this way.

Lithium has been hyped up a lot recently, but it's fairly new technology, so hasn't been tested over time, and every small lithium battery I've used on laptops, cameras etc, has always degraded with use, so I imagine the larger version would have problems as well.

Nickel iron look good from what I've read about them, I especially like the idea of being able to discharge 100% without damaging them (but I wonder if that is marketing hype as well?). They will only last a long time if they're looked after properly, with electrolyte changed every so often. Also it is hard to tell whether the newly made ones from China will last as long as the older ones.

I am still interested in aquions. For newer tech, they have my attention. Toxicity is not what is claimed, basically edible or at least compostable active materials. Manganese can be quite problematic.

Better fire safety and general handling safety is always welcome.

Lithium needs a temp controlled environment and cannot be charged at low temps found at many installations.

Being able to charge 35kWh from empty in two hours instead of two days is awesome, however.... and being able to ebb and flow at low state of charge for a month or two without damage is also handy in our region.

Budget is nearly always the main determining factor in battery technology and size for a house battery. Budget spent on lithium could be used to properly size a lead acid one, ethical as they are and not have to recycle/re-purchase it as often, or it can be used to adopt new technology and see how it goes.

Lead toxicity is problematic and i look for phosphor-bronze terminals in order to avoid contamination during maintenance and installation. Usually found on agm or gel types.

This technology sounds very promising:

"World's first working thermal battery" promises cheap, eco-friendly, grid-scalable energy storage

Thermal battery

Fingers crossed it works out due to the low price and longevity without degradation

Interesting stuff Darren;   Lets hope they carry on and start mass producing!  Thanks for sharing!

Simon Allins wrote:Aquion energy salt water batteries are cradle to cradle certified and made of none toxic materials.
They can be fully discharged and left like that for months, they don't burn and should last a long time.
I have them for over 2 years and very happy with them....

The issue is having a very expensive system with no support including ability to get parts.

I thought these would be a great storage choice compared to what is available.

I was hoping the chemistry might be available in the patent so that people could build their own but it's probably not feasible. Just like my nephew and I can build batteries in Mason jars for the science fair but you would not want to run your house on them.

Is there a way to make ex-telco batteries last? A certain percentage we shouldn't let them get below?

Kate Downham wrote:Is there a way to make ex-telco batteries last? A certain percentage we shouldn't let them get below?

Keep them above, say, 90-95% and they should last a short while - though the telco presumably got rid of them for a reason.  If they were still perfectly good batteries, it's unlikely they'd be tossed out.

There are a wide range of design parameters you can tweak while building a battery, and the UPS/telco batteries simply aren't designed for cycling.

You see it in how lead-acid batteries are rated.  A typical car starter battery is sized and rated by cold cranking amps - they're designed to put out a ton of amps for a very short period of time, then be fully recharged.  They will have a large number of very thin plates (the surface area is how they generate current), but if you drain them significantly, they're damaged.  I've found that a typical car battery can handle being fully discharged about once and recover, but the second time you do it, the battery is shot.

A deep cycle battery (like I have in my office) will be rated in capacity - amp-hours.  They can be deeply discharged without much damage, though it's best to avoid it when possible.  But, because they have large, thick plates designed for cycling, they don't provide nearly as many amps.  Despite being the same size as my truck batteries, I seriously doubt my office batteries would start my truck in the winter.  They're just not built for it.

The "marine deep cycle" batteries live somewhere in between, but good luck finding a datasheet other than a price tag for them.  I won't consider buying anything for energy storage without a very nice datasheet to tell me what I can expect.

Telco/UPS batteries are far closer to starter batteries than deep cycle.  They're designed to bridge an outage, and (depending on the facility) may be running at a very high discharge rate for a short period of time while the generators spin up.  They're just not deep cycle batteries, and you can't expect much life out of them if you ask them to do it.

Russell, it's good to have a fresh voice contributing to these forums. Welcome.

I meant my statement as a wishlist, as you insinuated. I urge you to remember all the things once considered impossible, including human flight, landing on the moon, getting bananas in North America in winter, or at all, and having any control at all over epidemic disease.

The impossible is simply an indicator of our level of progress and understanding.

Instead of suggesting that such is impossible, maybe you could suggest what form of energy storage is best for each stated goal, and where each fall down. Perhaps hybridisation within systems is the answer, as opposed to a more panaceic option.

And on another note, does anyone have information on the new cryonic hydrogen fuel cell technology? I will try to find the article I was just perusing.

-CK

This is a great discussion.  I just watched this video and nickel-iron batteries sound good but also some drawbacks (mining of nickel?) and space/weight?   Nothing seems perfect that's for sure but I appreciate learning the possibilities that are being tried and proven.        

Chris Kott wrote:Russell, it's good to have a fresh voice contributing to these forums. Welcome.

Thanks.  I hold less "techno-utopian" views than many, so some of the tech forums and I don't get along quite as well.  Off-grid (and even on-grid) power systems are an interest of mine, but my views don't line up quite as well with the mainstream on those points.  I'm far more on the side of, "You know, these problems get an awful lot easier if you don't demand as much power as you want, 24/7/365, regardless of the environmental conditions outside."

I meant my statement as a wishlist, as you insinuated. I urge you to remember all the things once considered impossible, including human flight, landing on the moon, getting bananas in North America in winter, or at all, and having any control at all over epidemic disease.

The impossible is simply an indicator of our level of progress and understanding.

That's not a particularly useful way of scoping the problem, though.  First, I don't care too terribly much about what may or may not come down the road, maybe, at some point in the future, if it can manage to escape the lab (see graphene).  I'm more interested in practical energy storage designs with today's proven technology.  If one goes by press releases about battery tech, I should be able to propel an ocean liner across the ocean at hydrofoil speeds with a battery roughly the size of a dorm fridge.  Very few of those advances ever make it out of the lab.  I pay enough attention to that realm that I'm regularly asked about them, and my response is always the same: "I bet it won't."  I'm almost always right.

With the exception of diseases, all the things you list are simply a matter of being able to throw more energy at problems.  We knew how to fly (glide) long before we could get an energy dense enough solution to sustain flight.  I'm less than convinced that throwing yet more energy at the problem is going to be a good solution for energy, going forward.

We've also done a pretty complete job of exploring the problem space for many varieties of reactions, batteries included.  There are remarkably few secrets left in chemistry.  The book "Ignition!" is a fascinating (and occasionally horrifying) read on the history of the liquid rocket propellant program.  It was a massive amount of work during the 50s and 60s, but has largely tapered off because we found just about every combination that works, depending on conditions.  If you eliminate stuff that's an unholy nightmare to work with, is liquid and stable at workable temperatures, and has good performance, there are only a few combinations one ends up with - and if you look, modern rockets are using just a handful of propellant combinations these days.  It's because they're the best set of compromises - and, importantly, they're affordable.  You could build super expensive exotic propellants, but they don't tend to perform enough better to justify the costs.

Batteries are similar.  We know what works, we know what might work (see lithium sulfur for one that's having a hard time getting out of the lab with more than a couple hundred cycles worth of lifespan), and we iterate on the previous ones (the last decade or two of lead acid has actually been fairly exciting).  But there just aren't that many chemical combinations you can get good energy/power density out of, and a lot of the ones battery engineers look longingly at are stubbornly resistant to actually working.  Metallic anodes are an example of one that we know will improve density, but they simply don't work well in practice - you get dendrite buildup, and shorting out a lithium cell is the sort of excitement best left to other people on YouTube.

Instead of suggesting that such is impossible, maybe you could suggest what form of energy storage is best for each stated goal, and where each fall down. Perhaps hybridisation within systems is the answer, as opposed to a more panaceic option.

I did just that.  Does it move?  Use lithium of some variety.  Is it stationary storage?  Use a modern lead acid chemistry.  I could go deeper into the variants of lithium, but they don't matter for stationary storage because I don't think it's the best set of compromises.  Flooded lead acid, in particular, is quite tolerant of abuse, is easy to monitor (a voltmeter and something to measure specific gravity will tell you just about anything you want to know), and lacks the energy density to be exciting.  If you really abuse them hard, you might manage a hydrogen explosion - but even that's difficult.  And that tends to rapidly disassemble things, not light them on fire with toxic fumes (see a lithium runaway - ideally from far upwind).  If you have halfway decent venting, you don't even manage a hydrogen explosion.  The chemistry simply lacks the energy density needed to be exciting.

Plus, it's nearly 100% recyclable.  Reprocess the containers, smelt the lead, purify the acid, replace a couple bits of separator, and you've got a brand new battery for fairly little energy.

http://www.trojanbattery.com/pdf/TBSALES_recycling.pdf is an overview of the process.  Lithium recycling is far from that well established.

And on another note, does anyone have information on the new cryonic hydrogen fuel cell technology? I will try to find the article I was just perusing.

It's almost certainly not useful for small scale.  Anything involving cryogenics, or high pressures (or both) doesn't tend to scale down very well at all.

Marta Meengs wrote:This is a great discussion.  I just watched this video and nickel-iron batteries sound good but also some drawbacks (mining of nickel?) and space/weight?   Nothing seems perfect that's for sure but I appreciate learning the possibilities that are being tried and proven.        

Space and weight don't matter much for stationary storage.  Round trip energy efficiency matters somewhat, and nickel iron is dreadful on that front.  Maintenance also matters, and they come up quite short on that front.  They operate as quite effective oxygen/hydrogen generators, though!

The most ethical batteries or a renewable energy system will be high capacity storage batteries made from the kenaf plant. Kenaf is renewable where I don't see lithium or nickel-iron as being renewable at all. Please correct me if I am mistaken. Preliminary tests with industrial hemp high capacity storage batteries took place in an electric vehicle that traveled 200 miles before needing recharging. What surprised me is that the time it took to recharge was 5-6 seconds. Preliminary experiments with kenaf show promise of being capable of being a resource for kenaf solar nano sheets. In theory 3 nano sheets thick, stronger than Kevlar and 75% more efficient. It is expected to have a workable prototype with manufacturing specs in the near future. Once the specs are available we will be able to evaluate the overall process and determine just how ethical kenaf may be, and if it should be used in renewable energy systems.

Aquion is out of business, but Greenrock is a company in Austria that uses the same technology:
http://www.bluesky-energy.eu/en/greenrock-saltwater-energy-storage/

Made in Europe
Advantages: low environmental impact, high temperature tolerance, low- zero maintenance
Disadvantages: big/heavy, expensive

I am considering this for an off grid use in Portugal, I will not be there frequently, so the no- maintenance component is attractive to me

Took a look at this from the daily post. The first question that pops into my mind is: What is Ethical? Honestly, for many people Ethical means "anything we can get away with." I worked for a (government owned) company for years who called themselves "Ethical" but I saw things that I would not class that way. One small example: Hire a company to build some plant infrastructure then delay paying until the company they hired went bankrupt... get the cheque back in the mail and go "Oh well." Ethics is an interesting subject, but so poorly defined that use of the word is almost meaningless.

Two types of batteries I would like to see mentioned, one new and one older. The new one is liquid metal with two dissimilar metals, one floating on top of the other. The case does have to be able to stand heat as the metals used have a higher melting point. However, heat input is not required as both charging and discharging create the heat required. Only of use for stationary applications, but still interesting. Lifetime not known really, time will tell

The old? Flooded NiCad. I know the "Cad" is a problem, but they have a life similar to NiFe, can take abuse similar to NiFe, can provide much higher instantaneous output current. May be had used from either the air industry or the mass transportation industry as they are used in trolley buses and and light rail transit. I would suggest that with attention to charging with a similar to what is required for LIon batteries, even sealed NiCad could last a long time.

We are of course all waiting for small high storage supercaps (ultrasupercaps?) for which I am keeping my fingers crossed...

Another thought, not really efficient either, is energy storage as heat. Not water thank you, but something with a higher boiling point (oil has been used). Insulation is a problem, but in a stationary use, 10 feet of insulation is not troubling. Recharge can be either from solar or dead solar (aka trees). Some of the highest energy use is heat anyway, especially in cooler climates. In warmer climates it is interesting that many chillers can be run with heat directly.

And finally, not a battery at all, are projects like the Kilowatt. A 1 to 10K thermonuclear generator being developed by NASA for use off world. They last 10 years... at full output, but can be throttled. Probably safer than any of the batteries discussed above. Capturing the waste heat rather than radiating it would probably double it's effective output. Sunshine or rain not a problem, no snow removal needed. I suspect the liquid salt reactor would be too big for the average homestead, but probably ideal for a small community. (it would also be an ideal place to get rid of spent fuel from kilopower generators used on local homesteads.