Buy Your Friends Batteries
domenkozar.com
domenkozar.com
Being able to cut over your entire house from grid power to a battery requires an invasive, expensive change to most connections. I wish people would stop breathlessly promoting batteries (which are good! we need decentralized storage!) because "you can use them to run your fridge, router, etc". Yes you can, but for almost all consumers it's an order of magnitude more effort and cash compared to just buying and plugging in a battery.
https://duckduckgo.com/?q=Uninterruptible+power+supply+refri...
it's the easiest, safest , most affordable and most reliable emergency solution ever available.
Running HVAC is usually more of a concern, especially in winter or peak of summer, and those aren't device that you can hot-plug, and a small battery wouldn't help there anyway.
I like the idea of whole-house batteries, but to really make it practical you're talking about thousands of dollars to the battery, install, etc. And you still don't have extensive run time, which is why I think you see most people still leaning towards permanent or portable generators way more than batteries.
But I would advocate that "zero resiliency" needs to be seen as being socially irresponsible. It is socially irresponsible that as soon as a service goes out that you are immediately in an emergency. You should not offload basic resiliency on to emergency services. Yes, if you take a direct hit from a tornado you're going to be leaning on emergency services, but the house a quarter mile from touchdown that may be out for three or four days needs to be able to deal with that. If nothing else, emergency supplies are a lot cheaper when it's not an emergency.
Don't let the perfect be the enemy of the good, and especially so when perfect is so much more expensive and so much less relevant than the good.
Sure, but that's not a remotely accurate description of a house without a backup battery or generator.
I grew up in hurricane country and weathered many bad storms. Losing power does not put you immediately in an emergency. If you don't open the fridge much, your perishables will last a couple of days. Non-perishables will last much longer. Having a battery is the difference between "we can hang out and grill dinner for 5 days before we need to hit the road" and "we can hang out and grill dinner for 6 days before we need to hit the road". That distinction does not significantly change your strategy.
Losing water is a much bigger emergency but is thankfully rarer and a backup battery won't help.
Climate change will change this story somewhat in the South. If you are in a very hot climate, elderly, or have other health issues, then losing electricity and air conditioning in the summer can be an immediate emergency. Again, though, A/Cs consume so much electricity that a backup battery won't help you much.
I think you're significantly overestimating the emergency value of a battery backup. Loss of electricity is rarely a rapid emergency. In cases where it is, a generator will at least give you as much power as you care to store fuel.
For $2k you can buy 3 Ankers and distribute around the house. With a propane camp stove you can cook. So the only utility failing during a power outage is your air conn. If it’s winter you can run a gas fireplace to keep warm.
In my area we have power outages in the fall and winter wind storms due to trees falling. We need electricity for the fridge, fireplace, lighting , internet & devices. Lithium batteries work great. We get a few outages every season, usually for 2-6 hours .
My neighbors have a generator for “emergencies” and don’t end up using it because it’s such a PITA. He has it for SHTF, but then he will have to consume the gas from his cars (and siphon it), which means making the decision between home comfort and evac.
My point is that every solution covers a range of scenarios based on convenience, cost, resilience, versatility and more. There is no one size fits all .
And now these lithium battery backups provide a broad amount of coverage that is safe and convenient for novices to run.
1 - https://www.homedepot.com/p/Generac-14kW-Air-Cooled-Auto-Sta...
You should be able to expect at least 4-6kwh per gallon at the generator output. So $25 worth of gas in a 5 gallon can stores 5x the energy of a $2000 battery. The only maintenance I've done on my generator is to drain the fuel lines after use. Maybe change the engine oil once or twice per decade. Apart from that, it runs just as well as 30 years ago when it was new.
True, the gasoline doesn't last that long in storage, but I just use it to fill my car every now and then, and get new gas.
deferring the maintenance is your choice, but I wouldn’t recommend it.
So do lawnmowers and chainsaws.
>Fuel storage is complicated (you will need 30+ gallons a day, or about 2 sedan tank’s worth.
You put it in containers and put them in your garage.
>Connecting to your panel is expensive at least $2k+.
You don't have to do that. Just run some extension cords through your house.
> They are smelly and noisy.
So is everyone after a couple of days in the South without air conditioning!
> And if it’s a real emergency, everyone will know you have one , and eventually come knocking.
This is a feature, not a bug. It's how communities take care of each other.
> Sure, but that's not a remotely accurate description of a house without a backup battery or generator.
I don't mean it as one. Resiliency is my end goal, and "a reasonable amount" at that, not "I can reboot civilization from the zombie hordes with just what is in my shed". If you are already resilient with just a house and what it will naturally do without power, hey, great. A battery opens up options, but if it is not worth it, it isn't worth it.
It should be a social expectation that you can survive a reasonable 2-3 days without power and whatever other service outage you have without having to immediately hit the stores or drawing on emergency services. I do not care exactly how you achieve that. I don't care if you're carrying on like nothing happened in a well-lit house with AC on full blast or if you're eating beans out of a can and drinking bottled water. I just care that people should be expected to be at least a little resilient, for all sorts of pro-social reasons, that if you have your additional needs like an oxygen machine or necessary medicine that you have the buffer in place, and so on. (Which does imply certain perscription practices keeping you on a short leash are in violation of this, but that's another discussion.)
My point is just that a cheap battery backup does not have a significant effect in the resiliency strategy for most people.
I am certainly not a prepper, but even viewing that scene from the outside, it is absolutely rife with what I would call "preparedness theater". Things you can buy (it's always about buying stuff) that would save you in some imagined horrific scenario but where the odds of the scenario happening in just the right arrangement where that object helped are infintesimal.
Like, yes, if your car drives into a freezing cold deep lake and you are somehow too incapacitated to open your seatbelt but not too incapacitated to use a knife, then keeping a dive knife in your glove box next to the ceramic "break windshield" thingy might be worth it, but you're more likely to win the lottery than have that happen.
There is a set of people whose brains are wired such that they are easily nerd sniped into obsessing about these sorts of things. When they do, they are also compelled to share it and spread it like some kind of mind virus. It takes a certain amount of mental discipline to not fall down every one of those rabbitholes. I believe the author telling the world to arrange joint battery buying parties for friends is well along that path of crazy.
Don't waste time and money organizing a joint battery purchase for your friends. Keep some non-perishables and a few gallons of water in your house. Fill your gas tank before it gets all the way to empty. Learn how to cook and some basic first aid.
What other option is easier or more affordable? A generator has to remain outside, so it needs panel connection ($$) , lots of extensions ( $, hassle), needs a generous fuel supply, and regular maintenance.
And plug-in solar is becoming legal in the usa. within 3 years everyone will be running these little things, and you'll come around.
So you're back to getting a tranfer switch installed or lots of cords anyways.
That duration was tough for various reasons, but fridge and freezer were not really an issue.
I was very happy when they changed to 2 hour outages (albeit twice as many), and then even happier with not having load shedding for about 2 years now.
It's clunky and haphazard, but it can work well-enough for rare use.
But one of the big sells in the article for this device is that it can be used to buy power when it is cheap, and sell power when it is expensive (at least in markets that support that kind of operation). This can be good for the owner (who can make some money doing it), and also good for the grid (the price fluctuates when supply and demand aren't well-balanced, and this function helps to balance things).
That kind of functionality, on its own, can tend to require some real wiring changes and permitting.
(Or not. Electricity rules vary wildly around the world. They aren't even necessarily consistent within one nationality.)
[1] About 96 hours, major storm took down a ton of trees through the whole metro area that took days to clear.
Also, according to the article, it seems to pay itself back in 11-12 years. I'd rather pay the little extra to not have a huge lithium battery in our appartment that cannot be extinguished with a normal fire extinguisher if it decides to ignite itself.
Winter storms tend to come in cold stretch’s that can cause major freeze havoc.
And, sure: I can get by very well with refrigeration, networking, computing and/or TV, and lights during a power outage. But those loads need to be segregated, or it just doesn't work. That adds more expense.
And since those segregated loads don't even come anywhere near 3kW, it isn't clear to me how I'm to be maximizing my local use of surplus power events.
There are grid-interactive battery solutions from companies like EG4 that can go betwixt the entire house and its grid connection, but this isn't it.
If things aren't segregated and the power goes off while I'm cooking, the aircon is running, the water heater is doing its thing, or whatever, then: I exceed 3kW.
3kW is the maximum that the device can supply. If load exceeds maximum, then something will (must) fail.
Hopefully it fails gracefully, but I mean: I've been married before and I understand how terrific and fantastic it can be when things go slightly wrong at home when I'm not around to address them. The less Rube Goldberg my creations are, the more peaceful my life is.
(None of this modern name-brand grid-tied stuff is any particular danger to linemen. It won't output anything on those terminals if it doesn't have an AC waveform to synchronize with.)
The Stream system: Connect the device to the grid to enable it to feed power into the grid or draw power from it when solar energy is insufficient. This can be done via a standard home outlet (if permitted), or through a circuit breaker. [0]
0. https://manuals.ecoflow.com/us/product/stream-ultra?lang=en_...
There's a pretty massive middle ground between "plug in a battery" and "rewire the house.
Who says? Say I need my fridge, freezer, router and a light or two. That's $4k. Whole house? $25-35k.
Also, I have a wood burning stove and piles of firewood).
It seems australia has very low friction
and US with our power companies, significantly more
- where you going to find an electrician?
- do you need someone to design your grid-tie plan?
- when will the power company approve your connection?
I've had friends wire their house, have to really work to plan the setup, and be stuck with a working system offline while PG&E approves slowly
Another point: People might be better served NOT buying a battery, instead getting an EV and wiring it into their house.
for example: https://www.tesla.com/powershare/
or just "bidirectional charging" for other brands
Things will start to get interesting where €1600 don't buy you 5kWh but double or triple the amount.
I can imagine most people are better off either investing like I said or in insulation.
The investment point still stands, though you could argue both come with risk/reward, energy prices aren't guaranteed to be stable.
FWIW my high voltage battery pack has almost 365 cycles and is still at 100% state of health.
Usually you can buy ice, but when I had a ~36 hour outage a couple years ago, I couldn't. Most stuff was fine for that long, but 2-3 days would've meant tossing pretty much the entire contents.
(Plus, I don't have cell service where I live, so being able to power my router is pretty useful.)
This is probably a bad move if you live in a city. It makes more sense in rural areas.
At that point, wouldn't it be easier if everyone just bought their own? And then whoever has the latest birthday doesn't have to wait a year to get theirs.
I love the spirit behind this but it's strange advice. I consider myself lucky to have a healthy roster of adult friends, and I still think getting 16 of them to spend significant money on each other's birthday would be a big ask to pull off.
https://solarunitedneighbors.org/
Europe has quote a bit of renewable generation currently that is curtailing or otherwise going unused, and needs all of the battery energy storage it can get (residential, commercial, utility scale) to convert curtailment into realized clean energy offsetting potential fossil energy usage (gas and coal).
Solar Power Is So Big in Europe That Electricity Is Being Wasted - https://www.bloomberg.com/news/articles/2026-05-13/europe-so... | https://archive.today/nAdiA - May 12th, 2026
> Hundreds of millions of solar panels have been installed in Europe, turning solar into the region's biggest source of power during summer months, but the system around it hasn't kept up. A record amount of electricity is being wasted because grids can't handle the surge in output, with about 40 terawatt-hours of electricity expected to go to waste in the coming months. The glut of solar power is pushing power prices deep below zero during peak solar hours, eroding returns for producers and forcing them to shut down plants, with consumers potentially paying twice for the subsidies and compensation.
You may not have £100,000 but if you get 1000 people with £100 then you can buy a house.
Obviously the birthday system doesnt address the interest, but I'm sure your friends would be ok paying interest right?
Reinventing building societies seems very cool to me -- it's a little more nuanced than the birthday thing, but it's a system that can work with assets that generate value.
Think about it like a secret santa with a $20 limit - wouldn't it be more efficient for everyone to just do what they want with $20? You're "purchasing" time and connection with friends.
I also don't get his example calculation. He mentions that average price in Germany is 38c/kWh, but in the table it's suddenly 4c min vs 13c max (or 40 vs 133?). That doesn't compute.
For people who don't have access to banks, they form "savings clubs" where there will be, say, 12 people who put in $100 per month, and one person takes the pot every month. The idea is that if you keep the money yourself, then you're socially pressured to spend it when there are holidays or guests, but if it's locked up in the savings club, you can't spend it, and then you get a big lump sum to spend on a large purchase that would be otherwise hard to save for.
1 - degradation: assuming the 15 years battery life / 10.000 cycles number from the datasheet is accurate, and that the manufacturer considers 70% capacity end-of-life, this pushes the payback time from 11.1 to 12.7 years.
2 - The article calculates the savings with:
> daily saving = 4.5 × expensive price − 5 × cheap price
but this is wrong because it assumes that grid charges fully cancel out. The article generally does a poor job at explaining this, but essentially it proposes you overbuy electricity when it's cheap and use it when it's expensive. The difference of those two, €0.133/kWh - €0.041/kWh is much smaller then the average electricity price of €0.3869/kWh because the latter also includes taxes and grid charges. So with 90% efficiency they end up with the formula above, but completely ignore the fact that from the grid's point of view, the total electricity consumption increased. On the flipside, it's also taking EPEX prices directly, pre-VAT, so you actually save 19% more then the difference 0.133 - 0.041 = 0.092. So the actual formula should be:
> daily saving = 1.19 × (5×0.9 × expensive price − 5 × cheap price) − 5 × (1−0.9) × grid charges
At a average rate of 21 cents/kWh for total grid costs (including VAT) that comes out to a payback time of 13.71 years.
So yeah, buying batteries alone doesn't make sense. You need solar or wind to charge them, so you actually avoid the grid charges. So that instead of saving 10 cents you save 40.
This seems like the hardest step. The costs of "just a battery" are much lower by comparison.
If you only cycle then in the 20-80% range, they'll last much longer (at least for NMC cells, not sure how LFP works).
Tons of EVs these days are being made with what, 200-300mi range of battery pack with some internal buffer as well so they're never really going 0-100%? So what, we'll be generous here about the 20-80% and think 160mi of range used every day. That's 58,400mi of driving per car! The average US car does closer to 14,000mi. Being generous, that's 4x the wear cycles of a normal US automobile.
Those prices are high. You can get 2.56kWh for 270€ on Aliexpress, delivered locally from Germany.
What could possibly go wrong? The things that people do.
Personally, I'd like the company to be in the EU so that I can at least sue them if it burns down the house.
There are even cheaper ways of starting a fire.
I guess Europeans have more friends than Americans -- I can't think of 32 people I'd invite to a birthday party, and certainly not 32 people that I'd expect to give me a €50 gift. I haven't received a real birthday present from friends (beyond a cheap gag-gift) in decades.
I guess it's very location-specific, but I haven't had a power outage longer than 1 minute in the past 5 years.
Remind me why I should buy the battery? It clearly can't be because it makes financial sense to just have the battery.
I want one, yes. But it sure as hell wouldn't be to save money. It'd be to have something if and when the grid falls over due to negligence.
I remember having to replace the lead acid battery in my UPS every 2-3 years, which seemed like a waste of money considering my country's power grid is fairly stable apart from the occasional blackout from lightning strikes.
Check local code before proceeding!
The whole system is.. not great, but it's even cheaper to have a battery than this post makes it sound.
Gift should be ... gifts
Many are in use all over the world in off-grid cabins and similar.
You do need to take care that they are installed correctly, and maintained properly, but that isn't much different than a natural gas connection, or even normal everyday electricity.
EV battery degradation from this use case is irrelevant. EVs are consistently hitting 300,000 miles with 90% capacity, so let's not belabor this point.
Nope.
I suppose that future V2X systems will incorporate direct plug-in tech, but note the transfer switch used by the system in the video.
While I do like the idea in theory, I don't love the inherent nudge towards off the shelf productized energy storage that will be placed somewhere without much of a plan, and then basically invites rewiring with extension cords. I get how those things are appealing for camping or determined apartment DIYers at the like, but moving them from a seek-them-out "pull" dynamic to a here-you-go "push" dynamic seems like asking for problems from people not thinking too much about storing 5kWh.
(plug-in batteries aren’t actually legal here yet, but likely to become so next year!)
yeah sure everyone has 100€ to spend on friends, at least once a month.
What kind of reality does he live in ?
Maybe the author is privileged and it's fine, it's not because you personally can't afford any gift that the author is disconnected, he might not just be talking to everyone on earth.
1. You have ~15 friends and you all have houses.
2. All of you can confidently allocate €1600 this year towards one major component of the upgrade, and believe you will benefit from it in the next ~15 years.
3. All the friends make enough money that they're confident anything going wrong with €1600 loans/debts won't cause pain or problems in the friendship.
How rich do you need to be for the mentality of that last one? AFAICT that's ~3% of yearly salary (pre-tax) in Germany.
Personally, I do not want my friend group to be tangled up in a financing scheme, and if I wanted a financing scheme I wouldn't do something half-assed that could explode into acrimony if anyone chooses (or is forced by circumstance) to exit having contributed without receiving or vice-versa.
I could understand friends having good-years helping out ones having bad-years ("banqueting" [0]) but what's being proposed really doesn't map to that.
[0] https://acoup.blog/2020/07/24/collections-bread-how-did-they...
You would certainly need the owner's permission, and investing in the kind of adaptations needed might not be something most renters are interested in when it's not their own place. A battery has to be integrated into the whole electrical feed, and a responsible owner might insist that this is a permanent installation and something you can just take with you when you leave. Or if you do, undoing the install will be similarly costly. And who knows if your next place will allow you to install a battery as well.
I don't think you can realistically install it in an apartment, due to fire regulations, and it needs a lot of space. Personally, I live in a 74 m2 apartment, and there's simply no room anywhere. Wiring is another matter; electricity comes through shared risers I don't control.
Now, you could use the battery as a pass through power source, but then you'd have to change all the wiring in your home.
It might not actually be "buy one-another new cars" territory, it's closer to that than paying for your friend's coffee or buying an appetizer for the whole table.
Batteries installation is not about money , average LiFePo4 battery life is around 10 years, so you will save nothing, unless you have some local generation like solar panels. In this case you could shrink payback time to 5 years instead of 10 and it makes some sense.
But the biggest problems here 2: 1. there a critical point after installing a huge amount of balance batteries the diff between day/night hours would be mitigated. And prices may down 30%. As result economical factor of installing energy storage systems would be very questionable. However cheap energy will increase energy usage by homes and industry and this may/might/probaly/i_hope. boost economy
2. The second factor riskier because when many people are installing energy storages and become independent of power grid, or even disconnects from the grid, there still exists power grid you have to support. Right now the price of grid support included in energy bill for electric company. The grid usage price is stable , it doesn't matter you support 1 person or a 1mln residents city. So the less people are using THE GRID - the higher prices for the rest people. And those high price forces rest people to disconnect from the grid. In general we may/I_hope_not to have situation with plenty energy islands and no more national grid systems