> Create a battery birthday club. Buy each friend a battery on their birthday until everyone has one.<p>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 think the point is that breaking it up makes the cost more palatable. It's also easier to convince people to spend a bit of money for people they care about than a bunch for themselves that they don't strictly need. People also often struggle to think of gift ideas for birthdays.
True, but you're still buying an entire battery yourself in the course of a calendar year.<p>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.
Best gifts are sub $5 and from a thrift store, like a funny shirt or mug.
But then you still have to buy birthday presents on top of that
If everyone's giving everyone the same gift, it's not really a "gift" any more, more of a p2p buy-now-pay-later arrangement (which isn't a terrible idea, but it's suboptimal for those with later bithdays).
Yeah this pretty much just a “tanda” except everyone pitches in to get the battery instead of paying out to the birthday person.<p><a href="https://en.wikipedia.org/wiki/Tanda_(informal_loan_club)" rel="nofollow">https://en.wikipedia.org/wiki/Tanda_(informal_loan_club)</a>
Might as well just have an annual theme and try to negotiate a bulk discount.
it's simple. if i were part of an economy, we would all just act rationally. that way everything would be efficient
Not everything needs to be optimized. Probably only rich people would engage in such a scheme anyway.
It's just fantastically naive on so many levels.
That's step one, next is your friends.
No. This is how building societies work.<p>You may not have £100,000 but if you get 1000 people with £100 then you can buy a house.<p>Obviously the birthday system doesnt address the interest, but I'm sure your friends would be ok paying interest right?
Yes, but I think the missing ingredient is that building societies "bid" to decide who gets to go first. Whoever is willing to take the smallest loan/pay back fastest gets preference.<p>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.
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It is like an energy storage cost cutting rotating potluck. blitzar mentions bulk buying in a comment, which is a great idea to drive down cost. Not sure what the EU version of that looks like, the US versions are:<p><a href="https://solarunitedneighbors.org/" rel="nofollow">https://solarunitedneighbors.org/</a><p><a href="https://www.brightsaver.org/" rel="nofollow">https://www.brightsaver.org/</a><p>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).<p><i>Solar Power Is So Big in Europe That Electricity Is Being Wasted</i> - <a href="https://www.bloomberg.com/news/articles/2026-05-13/europe-solar-power-wasted-as-electricity-grids-fail-to-handle-surge" rel="nofollow">https://www.bloomberg.com/news/articles/2026-05-13/europe-so...</a> | <a href="https://archive.today/nAdiA" rel="nofollow">https://archive.today/nAdiA</a> - May 12th, 2026<p>> 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.
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> You are also safer during a power outage. The STREAM 5000 provides up to 3 kW of off-grid output. Keep essential devices on its backup output and reserve some battery capacity, and your refrigerator, lights, router, and laptop can keep running when the grid goes down. An ordinary grid connection does not back up the whole house automatically; the backup output must be configured correctly.<p>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.
And the proposed battery solution only works at up to 3kW. My electric range uses more than that, and my water heater, clothes dryer, and aircon each come close.<p>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.<p>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.<p>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.
Not necessarily the point. If it provides a normal wall outlet I'm happy to plug essentials around for the one time per 1-2 decades this happens for longer than 4 hours and the fridge/freezer/laptop needs a boost
As long as you're not opening the fridge / freezer during the outage (and you have sufficient thermal mass of food in it) you don't need to worry about "boosting" it during a power outage of only 4 hours. I don't recall the rule of thumb off the top of my head, but for at least 6 hours I'd expect the contents of normal fridge / freezer to be just fine (as long as there's thermal mass there).
Yes, thanks, indeed I'd start doing this *after* 4h if I have such a battery since fridge, freezer, and laptop are all in different places and they'll run for 90 minutes to cool or charge and it's probably not bad to get around to all towards the end of the first day with no stress. It was just an arbitrary starting point really. Freezer contents are also all fine after 24h but maybe some edges got towards the thawing point. I've not tried it out and simply wouldn't care to find out
Can confirm from years of load shedding in the past in South Africa where my area had 4 hour outages.<p>That duration was tough for various reasons, but fridge and freezer were not really an issue.<p>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.
They said longer than 4 hours
The issue there is the plug would be on the battery which you're unlikely to have mounted in a convenient location for things like your main fridge, router, and computer. For me all 3 of those are pretty far away from the most likely places I'd put a battery bank. I have a mobile one I keep charged up for emergencies and long power outages and have a small portable solar panel for it for multiday outages.
I dunno. TBH I'd rather just let the food go bad than bother with the expense and hassle of having a battery and keeping it charged. I guess other locations may have less reliable grids than I do, but I've only experienced one power outage that lasted so long[1] that our food went off in my entire 40 years living in the Twin Cities area.<p>[1] About 96 hours, major storm took down a ton of trees through the whole metro area that took days to clear.
The device's primary use would be using excess solar power from during the day, or excess wind on rare occasions. This would just be a nice benefit and I just meant that it doesn't have to keep up with the whole house during an outage to still help out in a pinch
I can't even remember the last power outage we had that was not self-inflicted (a year ago our old microwave oven permanently tripped the residual current device).<p>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.
The cost/invasiveness of cutover is dropping. There is a relatively new category called "plug in solar" where the inverter/battery is smart enought to detect, sync and use grid power.<p>The Stream system: <i>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.</i> [0]<p>0. <a href="https://manuals.ecoflow.com/us/product/stream-ultra?lang=en_US" rel="nofollow">https://manuals.ecoflow.com/us/product/stream-ultra?lang=en_...</a>
I disagree. During an outage, you need your fridge and a few other essential items. A novice can plug into the back. The device tells you the load and whether you are exceeding. And you can test it at any time. For $600 you can get started without an electrician.<p>it's the easiest, safest , most affordable and most reliable emergency solution ever available.
For a relatively small battery like that, it's not going to last for days. In the typical outage where that battery would carry you, you can typically just leave the fridge closed and it will stay cold enough to prevent 99% of your stuff from spoiling. For most people (at least the US), it's not super easy to get at the plug in the back of the fridge anyway.<p>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.<p>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.
People need to make decisions about how much resiliency they want. A medium-sized battery greatly enhances your options in an outage. A "solar generator" expands them yet farther. A whole-house generator somewhat farther. It's a lot easier and cheaper if you don't insist that your "resiliency" be "I live my life with no compromises whatsoever".<p>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 <i>cheaper</i> when it's not an emergency.<p>Don't let the perfect be the enemy of the good, and especially so when <i>perfect</i> is so much more expensive and so much less relevant than the good.
<i>> 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. </i><p>Sure, but that's not a remotely accurate description of a house without a backup battery or generator.<p>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.<p>Losing water is a <i>much</i> bigger emergency but is thankfully rarer and a backup battery won't help.<p>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.<p>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.
> > 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.<p>> Sure, but that's not a remotely accurate description of a house without a backup battery or generator.<p>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.<p>It should be a social expectation that you can survive a reasonable 2-3 power and whatever other service outage you have without draining the stores or drawing on emergency services. I do not care exactly how you achieve that.
Generators don’t work that well. They need regular use and maintenance. Fuel storage is complicated (you will need 30+ gallons a day, or about 2 sedan tank’s worth. Connecting to your panel is expensive at least $2k+. They are smelly and noisy. And if it’s a real emergency, everyone will know you have one , and eventually come knocking.<p>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.<p>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 .<p>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.<p>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 .<p>And now these lithium battery backups provide a broad amount of coverage that is safe and convenient for novices to run.
People here buy natural gas generators[1] and just connect them into the existing gas lines. (I realize natural gas is not part of the utility mix everywhere.) Gas still flows when power is out, and common generators are big enough to power even A/C.<p>1 - <a href="https://www.homedepot.com/p/Generac-14kW-Air-Cooled-Auto-Start-on-Natural-Gas-or-Propane-Whole-House-Generator-with-Smart-Mobile-Monitoring-7258/337955897" rel="nofollow">https://www.homedepot.com/p/Generac-14kW-Air-Cooled-Auto-Sta...</a>
Fair, but I live in a wooded, semi-rural area and have had 7 outages this year, with one lasting over 8 hours.
sure we can quibble over convenience, but it's an outage, and you have to make it work. Look at the testing for the Anker Solix S2000 they are getting 2+ days of regular refrigerator use , which is what people care about primarily .<p>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.<p>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.
I really get where you're coming from, but I'm approaching this from the ~$1500, 5 kWh battery in TFA, which weights 50-60 kg, should be installed somewhere out of the way in a non-fire-hazardous manner. They're great, they can load-shift a meaningful chunk of daily consumption for most european homes don't just move these around to your freezer. They don't magically make you independent in case of grid failures, it's just not what they're for. And to get the average consumer to adopt these, the messaging about what they can and can't do should be crystal clear.
I mean, yes and no. Switching your whole house over automatically? Yeah, ok, that can get invasive and expensive. Running an extension cord from a battery/inverter or generator a multiport plug then to to your fridge, router and a couple of lights? That's about 5-10 minutes of effort.<p>There's a pretty massive middle ground between "plug in a battery" and "rewire the house.
If a fridge is your only concern, they make UPSes specifically for fridges.<p><a href="https://duckduckgo.com/?q=Uninterruptible+power+supply+refrigerator&ia=web" rel="nofollow">https://duckduckgo.com/?q=Uninterruptible+power+supply+refri...</a>
Germany is unfortunately not a good place to do this. The additional fees that you need to pay on top of the actual energy price are simply too high. And currently there is Katharina Reiche in charge which is actively fighting concepts like Energy Sharing.
11-13yr payback on something that is going to degrade ~3-4%/yr for 10 years (and limited terminal value) doesn't seem like the greatest investment unless you think the arb is going to widen a ton.
And any arbitrage is also trivially exploited by the electricity company, who has a much greater financial incentive and scale, so there's really no reason to think that it's going to widen in the future either.
Until grid-scale batteries are more established, you're <i>helping</i> the electric company, and that's why they're exposing the arbitrage. They're providing the incentives to nudge demand, so a home battery is doing exactly what they want (use more at time X, use less at time Y). Otherwise they'd just have the 24/7 price be whatever it currently costs when the supply and demand curves are tightest for them (when demand is highest and/or supply is lowest).
You could exploit it yourself, but only if you have several million to invest, less than that and it isn't worth the bother for the electric company to talk to you. Even at ten million invested you really need to have this is round one in your proposal with the understanding you intend to invest a lot more when it proves in the real world to work like you expect.
At my mother's workplace, there was a group of coworkers who each donated an amount of money per paycheck. Each paycheck, one coworker would get the lump sum that was collected for that paycheck. Similar concept to the one described here. They called it "susu" or something to that effect. If I remember correctly, it got messy when people would leave the workplace or when, occasionally, someone would get robbed on the way home.
Strange article, even though the idea is nice. $200 birthday presents might be a thing in America in some circles, but for German standards that is ludicrous (even 50 bucks is quite a lot, and then you need 32 people).<p>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.
>thirty-two people contribute €50 each.<p>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.
> 2. Confirm that their home, meter, and electricity contract are compatible.<p>This seems like the hardest step. The costs of "just a battery" are much lower by comparison.
You don't necessarily need to export power, especially for a small battery like tihs. Charge it up when power is cheap, and then configure it to discharge when power is expensive but only to match your current usage. You will need a CT on your main feed for it to balance against, but it can be done.
People don't tend to buy people large furniture because it's rude to assume that theyll want to keep something large and relatively permanent, much less something that requires an electrician to install.
How does 12 years required for this scheme to pay for itself stack up against the typical house battery's lifetime?
Also, as more batteries get added to the grid, the difference between the "cheap" and "expensive" energy prices ought to reduce.
Eh, there’s a tension there, becuase on the other hand as more renewable power is added to the grid, you’d expect divergence. Especially in countries which are letting people buy at spot price; that can be horribly expensive, or go _negative_.
Sounds like that's roughly the average usable lifetime for the battery, so you will break even on average.
I think most electric car batteries are still at over 80% capacity after 10 years usage, so hopefully you can use them much longer than that.<p>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).
Roughly the usable lifetime? Based on what?
> €1,600 for 5 kWh<p>Those prices are high. You can get 2.56kWh for 270€ on Aliexpress, delivered locally from Germany.
I don't think installing this kind of system at home is a good idea, especially considering the risk of fire. The amount of energy contained in a 5 kWh lithium battery is terrifing.
A Marstek Venus A 2.12kWh expansion module currently costs 180€ with a bunch of special aliexpress discounts.<p>The whole system is.. not great, but it's even cheaper to have a battery than this post makes it sound.
The 12 year payoff IF you manage the arbitrage properly really made me wonder why on earth you would buy one of these.<p>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.
This is what government subsidies/rebates are for - <a href="https://news.ycombinator.com/item?id=49298910">https://news.ycombinator.com/item?id=49298910</a><p>Gift should be ... gifts
You don't really need this, if you have an EV with V2X technology. There's already charging products that work seamlessly: <a href="https://www.youtube.com/watch?v=H0WGl_U5azs" rel="nofollow">https://www.youtube.com/watch?v=H0WGl_U5azs</a> and you have 100kWh of capacity, so you could sit out an outage for a long time. You can also configure the % cut off for the EV, so you still have enough left to drive if you need to leave.<p>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.
The only downside is that the battery won't last 11 years with daily usage
As the post already mentioned, also great for blackouts, of which more are coming for the developed world given climate change and infrastructure failure
And if you’re in the UK, wire them up to Axle Energy<p>(plug-in batteries aren’t actually legal here yet, but likely to become so next year!)
So I could buy a battery for ~$1,850 today that won't even break even in a decade (and hope everything goes well with this plan, not guaranteed in the slightest), or I can buy a 10 year US treasury note that'll give me another $1,000+ in profit at the end of the decade.<p>Remind me why I should buy the battery? It clearly can't be because it makes financial sense to just have the battery.
This is interesting, but is 3kW enough to be useful? What is the latest when it comes to home batteries? Has management gotten better to be smarter?
Call me old fashioned, but I just bring a can of gasoline and a pile of super soakers.<p>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.
>sixteen people contribute €100 each;<p>yeah sure everyone has 100€ to spend on friends, at least once a month.<p>What kind of reality does he live in ?
Yeah, TFA suggests you pay €1600 (~$1850 USD) to a loose group friends in one year, with the unofficial promise that those friends will "return" it to you in the form of a €1600 home-improvement.<p>Even if we assume <i>everybody</i> has a house, and <i>everybody</i> can float €1600 for home-improvements... For most people €1600 isn't so small that it won't hurt friendships if something goes wrong.<p>1. Does everyone in the group own a home where that good (the battery) makes sense? Do they unanimously want to invest in the battery?<p>1. Do you <i>want</i> your friend-circle to become a weird financing system? Are you OK with friendships getting ruined over money issues?<p>4. Would that circle be <i>any good</i> at the financing part, or does it start to collapse once any donor or recipient chooses--or is forced buy circumstance--to exit?<p>I could understand friends having good-years helping out ones having bad-years ("banqueting" [0]) but what's being proposed doesn't have those conditions or timescales.<p>[0] <a href="https://acoup.blog/2020/07/24/collections-bread-how-did-they-make-it-part-i-farmers/" rel="nofollow">https://acoup.blog/2020/07/24/collections-bread-how-did-they...</a>
And everyone lives in a house that they own, apparently.
You're getting downvoted, but for real this is so disconnected from what I'd say is feasible for most people. I and most of the people I know live squarely paycheck to paycheck, I can't afford to buy my friends birthday presents <i>at all</i>, let alone set aside that much per month just to put batteries in other peoples' houses. This feels like one of those things where the author doesn't grasp the privilege he lives with.
Surely not for _most_ people, but for people on Hacker News, in the correct age range to have a house, putting 100e aside really does not seem out of whack.<p>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.
Even where people probably could afford it I think spending €100 on a birthday gift would be excessive. It would be showing off.
Do they even have houses?
Does having a home inherently change disposable income?
In some cases yes, and they're not doing much better than I am.
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Most modern batteries like this are weatherproof and can be mounted outside the home. Most modern batteries use LiFePO4 chemistry, which while not perfect, is much less risky in terms of thermal runaway than older lithium ion batteries.
The Tesla Powerwall is only slightly larger than a pizza box and can be mounted directly on the wall. Most of the below images are outside the house, but some are also in the garage.<p><a href="https://duckduckgo.com/?q=tesla+powerwall&ia=images&iax=images" rel="nofollow">https://duckduckgo.com/?q=tesla+powerwall&ia=images&iax=imag...</a>
I have two Powerwalls mounted on my house and while I think they're fantastic and pretty compact for what they are, I would not describe them as anywhere near the size of a pizza box (unless you mean one of these things [1]).<p>[1] <a href="https://www.scottspizzatours.com/blog/worlds-largest-delivery-pizza/" rel="nofollow">https://www.scottspizzatours.com/blog/worlds-largest-deliver...</a>
Tesla powerwall is 44” x 24”<p>Where are you buying your pizzas?!
This battery uses a safer type of lithium chemistry that is less prone to overheating, though no large battery is risk-free. Water is used by firefighters to cool battery fires (they can reignite tho).<p>Install it outdoors or in a detached garage, away from anything flammable. Never in a bedroom, hallway, or escape route.<p>There are newer batteries tech that can't inflame.
Great piece and post, love the concept!
Anyone who can afford to own a home can afford their batteries and doesn’t need gifts. Renters are not allowed to modify their home in such a way.
No.