The "Allen Lab" YouTube channel is teeny-tiny, and has bare-bones presentation, but it has some of the best actual science content -- especially if you actually paid attention in science classes in school and are a bit tired of the "Mr. Wizard" level gee-whiz YouTube science stuff that covers material you already know. (That said, if you find those videos informative and fun, then knock yourself out! Each to their own.) (His channel's name is actually just "Peter Allen.")
I like tiny channels like these. Just need a good sound and stable video and content.
GreatScott, AvE, JeruGarcia lots are simple but they give a lot. Also there's guy like Robert Murray Smith but 1) he toys with you to make you search a lot 2) the framing is too wide and sound not smooth enough. Anyway.
I like this idea. For many off grid situations energy density and weight is not that big of an issue compared to cost. If instead of the size of a 'Powerwall' you had to have something the size of a coal bunker or compost bin, that wouldn't really be an issue at all if the materials were very low cost and I could build it myself.
You can build nickel-iron batteries yourself, and they use reasonably easy to source materials. The nickel is expensive though, so they can’t easily compete with lead-acid.
You can beat lead acid on lifetime. I looked into that for a remote installation instead of a half ton of lead acid every 8 years. I elected to do lead acid once more and then hope for a suitable lithium solution. I swear that half ton feels heavier every 8 years.
This could be a good stepping stone towards creating DIY batteries that have a useful level of power storage. Seems to tick a lot of boxes; cheap, abundant materials, non-toxic. Whilst it's not likely to be a good fit for all cases, it could help the growth of off-grid energy solutions, as well as being an interesting science project.
I wish there was a text explanation, I don't have the patience for video most of the time. How does this technology compare to already-commercialized nickel-iron batteries?
Unfortunately, there were no details about the proposed battery chemistry in the video either.
From memory, nickel-iron batteries have the following limitations for stationary storage:
- Relatively high self-discharge rate (though this isn't a big problem if you're buffering renewable electricity on a daily basis)
- Comparatively low energy efficiency, ~70%
- Hydrogen evolution by water electrolysis during charging -- a potential hazard, and one of the main loss paths driving the low efficiency
- Electrolyte water loss from electrolytic evolution of hydrogen during charging requires regular compensation with additional water
There have been a number of approaches to improve efficiency/suppress hydrogen evolution in nickel-iron batteries by the addition of organosulfur compounds. I don't think that any of those approaches are on the way to commercialization yet, though.
You're true on all of your points. But there's other factors that make them very interesting.
1. Since the electrolyte is a base (Sodium/Potassium hydroxide) you can make it out of wood ash in a pinch.
2. The batteries can handle all sorts of catastrophic damage - have a charged battery and run a gutter nail through every plate? It'll fizzle and discharge in the nail.
3. You can severely overcharge and undercharge with no ill effect. Our current NiMH, Lithiums and the like all have really bad effects when you under/over charge them. Blowing up is one such... err, "feature"
4. These batteries are known to last over 100 years. They were some of the first ones that Ford and Edison put in cars. Chalk this up to longevity (and no acid eating consumable lead plates).
Oh, and for your electolyte losses- true that you do need to top off with distilled water. But 'regular changing' is actually around 6 months to 1 year. I wouldn't be listing that as a major downside. I'd much rather add a few pellets of NaOH and some distilled every 6 months than pay for a new lead-acid battery every 2-3 years.
Also, it's worth noting that this is a research project. Test cells have been produced, but experiments are ongoing, so the final design is not set in stone.
Oh, great! I see that the separate YouTube channel's videos discuss the chemistry though the fund raising page's video doesn't. That won me over -- $100 donated. It looks like I have a bunch of videos to watch this weekend :-)
Can you just store the hydrogen? Or is it just so inefficient as to be useless?
Seems like batteries to cover 95%+ of your use case then having hydrogen backup for for covering rare weather conditions might work well for off grid setups.
On second thought, you realllllllllllly dont want to store H2 gas.
Having worked some in welding (I considered doing it instead of programming for a while), the problems with H2 are numerous. Firstly, it seeps out of any container you put it in. And I do mean any. Hell, even glass ampules in the chemistry have a hard time sealing H2.
Another major issue, is that H2 does "fucky" things with metal. Ever heard of hydrogen embrittlement? (1) You have cracks in your metal. Well, hydrogen, being as tiny as it is, also can bond with the metal. Gets in there, makes cracks bigger. Creates weird metal acids (H2FeCO4) and they attack more metal.
And if you're storing H2 gas in a regular container, you just made a time detonating fuse, and.... you don't know the time.
But yeah, H2 gas creation may be easy, but storage is super hard and really dangerous. And unless you can get H2 in liquid form, it's pretty low power density compared to things like octane.
That's the "battolyser" concept -- store and use the hydrogen from nickel-iron unit charging instead of wasting it. But round-trip storage efficiency is lower via hydrogen (if you want electricity as the end form of energy) and it increases complexity/cost to add systems for hydrogen. So the economics may not be improved even though the energetic efficiency would be.
I think the main issue with hydrogen is just that it's crazy dangerous and sort of hard to work with safely. It's highly flammable, and becomes violently explosive when mixed with oxygen.
It's easy to make - just pass current through water - but while all batteries are basically bombs, a key factor in their design is that they should go off very slowly.
Okay, but now you just have some steam and heat floating around.
It's gonna dissipate pretty quickly, not a great way to store power for the medium-long term. Hydrogen separated from Oxygen is where the useful potential energy difference is.
The idea behind hydrogen fuel cell batteries is that you spend your cheap clean renewable energy to split H2O slowly when energy is available, and burn the hydrogen when you need bursts of power. If you burn the hydrogen right away, you're just un-doing the water-splitting reaction and you won't have anything to use for power when the cheap clean renewable energy is not available, like during the night for solar power.
I think that the usual way to get energy back out of the hydrogen is just to burn it and let the hot pressurized gas power a steam turbine, but don't quote me on that. Or try it at home; scalding and flash burns are good things to avoid.
Could you use the steam to drive a turbine to recharge the batteries? You'd not recover nearly everything clearly but I'd imagine it's more than nothing.
I saw a chart a decade ago that projected when the cost of rooftop photovoltaic panels would be be less than the install cost, and it was before now. Looks like that happened around last year ($3 per watt for panel, $3 per watt for install cost):
With free energy all around us from the sun, the difficulty is no longer in collection. The next big opportunities from a profit vs effort descending perspective will be in areas that are causing friction in adopting renewables:
* legalities
* inverters (currently priced 2-10x higher than they should be for non-technical reasons)
At this point, I'd expect large solar and wind plants to be competitive with fossil fuels. The problem would be with storing power, so that it will be consistent.
My previous post was referring to individuals, rather than businesses. For a homeowner to install a PV system, based on your link, it would cost around $18,000. You wouldn't break even on it for 20 years, and that's assuming that you're still tied to the grid.
Once renewables are both cheaper than fossil fuels, and in reach for the average person, mass adoption will quickly follow.
I may have been off a little, grid tie inverters used to be too expensive but it looks like they've come down a lot in the last year or two. It's currently about $50/kW for computer power supplies and $100/kW for grid tie inverters:
So still a factor of 2x but there is room there for innovation. They will likely always be more expensive due to safety considerations for line workers etc though.
IMHO this is the component that is most likely to bring renewables to the masses because they can convert any kind of power to the existing standard.
I don't like it when people sell renewable sources of energy as "the cheapest source of energy available". If it were actually cheap then why do you need a community funded project? The problem with solar is storage but hardly anyone discusses that in the total cost of energy consumption.
These projects need to be transparent up front. To achieve the "cheap" objective you need benchmarks such as existing technology vs future technology. For instance, i believe they should state "our goal is to achieve $X/Kwh compared to $Y/Kwh of existing technology". That way you can see something measurable, scientific, and objective oriented.
I like the project so don't get me wrong. I just think they've worded it all wrong as what they are trying to achieve.
“If it were actually cheap then why do you need a community funded project?”
Seems a bit daft to me. They need $5000 to buy materials for their university research. If the project is successful the energy they store will be cheap. But doing the research and acquiring the energy are totally different things, so even if the latter is free the former is not.
Lots of things are cheap if you can amortize a large capital investment made upfront. You might need a lot of people to fund the project upfront so it can be cheap later. I agree transparency would be good though.
There are other cheap, abundant, and non-toxic rechargeable batteries. NiMH in particular fits all of those, the only downside is that its (slightly) heavier than the standard Lithium Ion.
Indeed, NiMH used to be the standard before Li-Ion took over. NiMH can pack nearly the same energy as Lithium Ion, except do it in a safe, renewable, non-toxic way without any exotic, potentially non-ethical materials (like Cobalt). NiMH is still widely available as well, virtually every rechargeable AA cell out there is NiMH.
"One inherent risk with NiMH chemistry is that overcharging causes hydrogen gas to form, potentially rupturing the cell. Therefore, cells have a vent to release the gas in the event of serious overcharging" [0]
Li-Ion has extremely low self discharge rate and very high power efficiency. It can also reach thousands of recharge cycles as long as you don't discharge it too deeply and don't overcharge it and keep it cool. It has no memory effect, so it can be recharged frequently.
