The Most Ethical Batteries for Renewable Bill Mollison explains a Trompe 1 day ago   03:22

Geoff Lawton: Permaculture Online
The main thing in renewable energy systems is the embodied energy: the energy over the lifetime of the product versus the energy of manufacturing it. Lithium batteries are used a lot because they are lightweight, but they don’t last. Lead-acid batteries, like car batteries, are also short-lived. An old technology, the nickel-iron battery, lasts a long time.

Lithium batteries are great when there might be a space or weight issue, but they are consumable products. Lead-acid batteries decays as they give energy. The nickel-iron battery powered the first electric cars, some of which had batteries that worked over 100 years later. These are not acid, but alkaline, made with a potassium hydroxide mix.

While they are only 1.2 volts, which means a lot of batteries and a lot weight, in a stationary situation, such as a house, the embodied energy is much, much better in nickel-iron batteries.

Key Takeaways:

- Renewable energy is best judged via embodied energy: the amount of energy it provides over a lifetime versus the amount used to produce the system.
- Lithium and lead-acid batteries both have short lifespans, decreasing their embodied energy, and as a result, they create more waste.
- Nickel-iron batteries, a very old technology, lasts an incredibly long time and have much more embodied energy.
- In a stationary situation, such as powering a house, nickel-iron batteries, though they require more space and weigh more, are a more ethical choice.

Comments 54 Comments

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john mcfadden
I just checked the price of these batteries which is a bit pricey although over time that evens out , but there is a chemist on YouTube that has developed carbon based batteries that are relatively easy to make . He is currently constructing a small scale production unit to start making them. His name is Robert Murray Smith well worth a gander
James Gant
Graphene super capacitors?
John Otvos
The challenge one might make to this video's suposition is if nickel-iron batteries are so great, why then has no major manufacturer designed a house charging system with them in mind?
The big down-side to NiFe cells is that they absorb CO2 from the atmosphere and it destroys the electrolyte. Here in the US, the chemicals needed to replace the electrolyte cost as much as replacing the cells with new. The basic cell has the lowest embodied energy, but replacing the electrolyte every couple of years is an embodied energy and wallet killer.
Manas Marthi
The link in Friday five mail for choosing "what's new priority emails" is redirecting to here.. not an email subscription page..
WOW - this is amazing!!! Please can we have a video on how to fix them up, or of great people like this man who can help us fix and use them?
C Carrier
Couple of important points that were missed out. From the previous research I did for my off-grid system, is that these battaries have a relatively high self discharge rate meaning that they will lose the energy stored in them even if you haven't used the energy. Also the electrolyte is quite caustic (KOH) much like caustic soda (NaOH) so would need to be handled with care and properly neutralised with an acid before being discharge onto your plants. Current availability and prices are not reasonable and finally they are quite bulky and heavy.
Santiago Nogueira
Betty Montgomery
Yess!!! This is a question that's been bothering me!
john mcfadden
Any body interested in new carbon based batteries that an be made by oneself should checkout Robert Murray smith channel on YouTube
sarah kuhr
Thank you for that information. I knew in my heart that there had t be something better than batteries we commonly use.
Richard Swan
Question and comment : The electrolyte, potassium hydroxide ( KOH ) is a strong alkali, as strong as sodium hydroxide ( NaOH also known as caustic soda ). Unless the hydroxide ions ( OH^- ) of the electrolyte have been adequately neutralised by a suitable organic type acid, or other chemical process ( through ageing ? ) that has the same effect, it is not be safe to put the old electrolyte in the garden without it being harmful. The potassium ions ( K^+ ) are good for the garden as stated in the video, in the correct doses. You can test the electrolyte pH to ascertain how alkaline it is for older ( unusable ? ) batteries, and hopefully they will be safe to tip when the pH is around 7. They may be close enough to 7 when they have expired, so I recommend testing for that just to be sure, when there may be some doubt. Maybe the authors of the video may just like to clarify that issue for me and also their viewers ?
Super cool. Hadn't heard of it to date, but will keep in mind for the future. Thank you for the education
Brandon Price
Any one know where - who commercalizes them..?
Marcus Busby
Great vid thank you! How about these Saltwater batteries, made in USA, can be scaled up to grid-scale applications:
*You left out too many details for the video to be useful.*
For a simple kickstart in understanding the NiFe Batteries, I would appreciate a rough comparison in size and weight to a 12V lead acid battery with 100Ah.
Pia's Permaculture Edu
Shaun Richter
Edison Nickel Iron Battery patents: US678722 & US692507 :)
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Bill Mollison explains a Trompe The Most Ethical Batteries for Renewable 1 day ago   07:23

To get Geoff's commentary on Bill's trompe, feel free to check out the more extensive video ("Hold Back the Rain" - thank you, Duran Duran) at The Permaculture Circle (TPC):

If you're not already signed up for TPC, what are you waiting for? It's free and takes 15 seconds (and you'll be able to enjoy an additional 100+ valuable videos / media resources on all things permaculture, ask questions to our teaching assistants, and join a worldwide community of permaculture enthusiasts). Full details + the 15-second sign-up box here:


Bill Mollison explains a Trompe:

Beginning with a small stream, we can let it out, leading it towards a box tunnel into which the water can free fall. At the top of this tunnel, we can install a large funnel apparatus with holes drilled into it and pipes, like drinking straws, leading to the holes and creating tiny air bubbles. As the water falls through the funnel, it pulls air with it into the tunnel, and because the water is falling faster than the tiny air bubbles, the air becomes trapped below. We can design a large underground chamber into which the air bubbles collect and become highly compressed with the water moving on unused. This air is isothermically compressed.

Isothermically compressed air is tremendously useful. It’s very clean, free of the vaporized oil found in air out of compressed, which means it could be used for scuba diving. More significantly, though, a little pipe could be run to the chamber, and isothermically compressed air can be attached to a shop with a spigot to give access to it. That air could then be used to drive any machine, i.e. power tools. It could be led into an insulated room and released as refrigeration and freezing. It could be bottled and used to run motors, actual cars, with the exhaust being cold rather than hot.

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