There are two issues with the articles calculations, that end up making the already bad payback time even worse, before considering opportunity costs. Numbers are for Germany since that's the more favorable case:
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.
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:
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.
> Create a battery birthday club. Buy each friend a battery on their birthday until everyone has one.
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.
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.
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).
It's not cost optimization its payment on installments..
Personally, I find it less convenient to have more than 1 bill and a group of 30 paying on average every 12 days probably makes it less convenient for anyone. But there are some strange consumers who like to delude themselves.
I've heard of people doing this kind of rotating "Everyone pays $X in each week/month, a different person decides how to spend it each week/month" thing. It's mostly for building social connection/community.
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.
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.
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.
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:
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).
> 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 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.
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.
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.)
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).
Can confirm from years of load shedding in the past in South Africa where my area had 4 hour outages.
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.
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
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.
Ah, right I was picturing an oversized car battery that you can lug around. Extension cord then? Not sure but this seems surmountable without having to rewire the house and get a permit or licensed unit for feeding the grid
The size the article is talking about are usually around 100 pounds or ~50kg at least. My solution is the much smaller Anker Solix C1000 and it's outboard battery extension. It can output up to 1800W sustained with a 2.4 KW peak and the two units together have about 2100 Wh of capacity. They're small enough to move around by hand when disconnected but can't do the kind of peak shifting the OP article was talking about so they're purely backup or car camping power. I used them to power my WFH setup while my electrical service was being upgraded a while ago though and it worked well enough.
Must be nice. I live in Virginia, outside Richmond. For the past 8 years, the power company has failed to provide me with even 3 nines of power availability (that means at least 9 hours of outage every year for the past 8 years. Just had a 17 hour outage as of last night, lost everything in my fridge. Again.)
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.
[1] About 96 hours, major storm took down a ton of trees through the whole metro area that took days to clear.
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).
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 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
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.
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]
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.
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.
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.
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".
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.
> 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.
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.
> > 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.
> 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.)
Winter is a better use case, because losing power during deep sub-zero temps can lead to plumbing damage and even be dangerous, but doesn't require too much power if heat uses natural gas as the main power source.
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.
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.
What are you running that uses 30+ gallons of gasoline per day? Personal AI datacenter? I barely use that much in my car per month.
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.
What’s your point? How long are you getting on 5 gallons? Maybe 10 hours if you’re lucky. And I hope you’re not using your 30 year old generator on anything with an IC – the power is too dirty to use with electronics.
deferring the maintenance is your choice, but I wouldn’t recommend it.
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.
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 .
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.
Exactly zero plug in solutions should be outputing power during an outage, if designed correctly, because they will be backfeed out of the house and into a grid. Most legislation directly addresses this.
So you're back to getting a tranfer switch installed or lots of cords anyways.
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.
There's a pretty massive middle ground between "plug in a battery" and "rewire the house.
Switching the whole house is cheap compared to the generator or battery needed to run everything in the house. Of you can't run everything then you may as well have nothing. The important things need a lot of power.
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.
Alternative systems are closer to 5 years payback if you have access to off peak energy. 3-4%/year degradation is very high, battery packs available in the UK from Fogstar are rated at 8,000 cycles with a 95% depth of discharge.
FWIW my high voltage battery pack has almost 365 cycles and is still at 100% state of health.
Add in that my freezer probably contains over $500 of food (and the fridge has less, but not none.)
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.
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 helping 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.
Let's assume the calculation is correct and you actually earn back in 11-13 years. You are better off investing the money in something like the S&P 500 where you'd double your investment in about a decade without the hassle.
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.
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.
I read the book Poor Economics[0] around when it came out, and it described something similar.
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.
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.
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_.
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).
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.
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.
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.
The hybrid inverter that allows you to plug the battery into your house circuit (DC -> AC) seamlessly is around $2-3k + installation cost, cause you're touching the main panel. Why isn't that in the calculation?
Do any US states allow plug in batteries like this (I know some allow plug in solar)? The installation cost of a whole home battery is what has kept me away so far.
That’s a good point. I had assumed the states allowing plug-in solar also allowed batteries, but according to https://pluginsolarguide.com , it’s only Utah so far.
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.
There are numerous systems available for this type of system that are professionally designed and built, and satisfy all kinds of local codes.
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.
Welcome to Ukraine where local people installed around 8GWt of batteries at home mostly because of huge outages after missile and ballistic terroristic attacks.
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
You don't really need this, if you have an EV with V2X technology. There's already charging products that work seamlessly: https://www.youtube.com/watch?v=H0WGl_U5azs 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.
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 thing about the EcoFlow Stream is that has things like phase alignment which allows it to be plugged directly into a household outlet without transfer switches to segregate grid phase from the phase of power created by the V2X inverter's phase. It also handles solar input.
I suppose that future V2X systems will incorporate direct plug-in tech, but note the transfer switch used by the system in the video.
As the post already mentioned, also great for blackouts, of which more are coming for the developed world given climate change and infrastructure failure
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.
Remind me why I should buy the battery? It clearly can't be because it makes financial sense to just have the battery.
Yeah, at the core it suggests each person lends €1600 (~$1850 USD) distributed in an unofficial and impromptu way, hoping to get it all back as a home-improvement good. That has some implications like:
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.
And everyone makes enough money that something going wrong with their €1600 payment/expectation isn't going to ruin relationships.
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.
Why can't renters plug a battery into their socket, too? As long as the electric house grid is rated for the specified power (might not be the case on some countries, or in extremely old homes).
I'm not an expert. But a Tesla Powerwall type battery is a big thing to install for a renter, is it not? I would argue it's more than installing, say, a washer or window AC; probably more like installing a wall heat pump?
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.
I'm not an expert here, but I don't think you're supposed to backfeed electricity into your panel while you're connected to the grid. Doing something like this (historically at-home solar) you'd need a way to disconnect from the grid physically, at least if you wanted to reuse your home wiring.
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.
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 at all, 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.
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.
I think the people that can easily put aside €100 for the birthdays of a dozen or more friends could also just pay the €1600 and buy the battery for themselves outright without having to wait for a birthday "surprise"
Call me old fashioned, but I just bring a can of gasoline and a pile of super soakers.
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.
In Germany you can use a "Balkonkraftwerk" that just plugs into any outlet and contributes up to 800W. You can also hook up solar panels to it up to 2000W (makes most sense with batteries). No need for the landlord to agree.
There are two issues with the articles calculations, that end up making the already bad payback time even worse, before considering opportunity costs. Numbers are for Germany since that's the more favorable case:
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.
> Create a battery birthday club. Buy each friend a battery on their birthday until everyone has one.
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.
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.
The first friend gets to share their experience with the group, that can then decide to keep buying for other members or not.
“Sorry y’all, now that I have mine I gotta say, not worth the price”
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.
https://en.wikipedia.org/wiki/Tanda_(informal_loan_club)
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.
The whole premise here is cost optimization.
It's not cost optimization its payment on installments.. Personally, I find it less convenient to have more than 1 bill and a group of 30 paying on average every 12 days probably makes it less convenient for anyone. But there are some strange consumers who like to delude themselves.
I've heard of people doing this kind of rotating "Everyone pays $X in each week/month, a different person decides how to spend it each week/month" thing. It's mostly for building social connection/community.
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.
That's step one, next is your friends.
No. This is how building societies work.
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?
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.
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.
It's just fantastically naive on so many levels.
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:
https://solarunitedneighbors.org/
https://www.brightsaver.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 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.
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.
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.
Why do you need to segregate them? Can't you switch the rest off? Or is the problem that otherwise you'd supply neighbors as well?
Just because it's the real world. :)
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.)
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).
Can confirm from years of load shedding in the past in South Africa where my area had 4 hour outages.
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.
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
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.
Ah, right I was picturing an oversized car battery that you can lug around. Extension cord then? Not sure but this seems surmountable without having to rewire the house and get a permit or licensed unit for feeding the grid
The size the article is talking about are usually around 100 pounds or ~50kg at least. My solution is the much smaller Anker Solix C1000 and it's outboard battery extension. It can output up to 1800W sustained with a 2.4 KW peak and the two units together have about 2100 Wh of capacity. They're small enough to move around by hand when disconnected but can't do the kind of peak shifting the OP article was talking about so they're purely backup or car camping power. I used them to power my WFH setup while my electrical service was being upgraded a while ago though and it worked well enough.
Must be nice. I live in Virginia, outside Richmond. For the past 8 years, the power company has failed to provide me with even 3 nines of power availability (that means at least 9 hours of outage every year for the past 8 years. Just had a 17 hour outage as of last night, lost everything in my fridge. Again.)
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.
[1] About 96 hours, major storm took down a ton of trees through the whole metro area that took days to clear.
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).
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 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
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.
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_...
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.
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.
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.
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".
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.
> 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.
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.
> > 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.
> 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.)
Winter is a better use case, because losing power during deep sub-zero temps can lead to plumbing damage and even be dangerous, but doesn't require too much power if heat uses natural gas as the main power source.
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.
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.
What are you running that uses 30+ gallons of gasoline per day? Personal AI datacenter? I barely use that much in my car per month.
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.
What’s your point? How long are you getting on 5 gallons? Maybe 10 hours if you’re lucky. And I hope you’re not using your 30 year old generator on anything with an IC – the power is too dirty to use with electronics.
deferring the maintenance is your choice, but I wouldn’t recommend it.
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.
1 - https://www.homedepot.com/p/Generac-14kW-Air-Cooled-Auto-Sta...
You’re right it’s more convenient than gasoline, but most of the other hassles apply (dirty/smelly, maintenance, noisy)
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 .
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.
Exactly zero plug in solutions should be outputing power during an outage, if designed correctly, because they will be backfeed out of the house and into a grid. Most legislation directly addresses this.
So you're back to getting a tranfer switch installed or lots of cords anyways.
The plug in technology available today accounts for that. Soon they will be available in all 50 states.
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.
There's a pretty massive middle ground between "plug in a battery" and "rewire the house.
Switching the whole house is cheap compared to the generator or battery needed to run everything in the house. Of you can't run everything then you may as well have nothing. The important things need a lot of power.
If a fridge is your only concern, they make UPSes specifically for fridges.
https://duckduckgo.com/?q=Uninterruptible+power+supply+refri...
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.
Alternative systems are closer to 5 years payback if you have access to off peak energy. 3-4%/year degradation is very high, battery packs available in the UK from Fogstar are rated at 8,000 cycles with a 95% depth of discharge.
FWIW my high voltage battery pack has almost 365 cycles and is still at 100% state of health.
FWIW i was just going off that fact that the warranty on the battery mentioned in the article only guaranteed >=60% after 10 years...
Add in that my freezer probably contains over $500 of food (and the fridge has less, but not none.)
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.
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 helping 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.
Let's assume the calculation is correct and you actually earn back in 11-13 years. You are better off investing the money in something like the S&P 500 where you'd double your investment in about a decade without the hassle.
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.
€1500 can already get you 16.1kWh.
The investment point still stands, though you could argue both come with risk/reward, energy prices aren't guaranteed to be stable.
But that makes you more dependent on externalities, a battery makes you more independent instead.
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.
I read the book Poor Economics[0] around when it came out, and it described something similar.
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.
[0] https://en.wikipedia.org/wiki/Poor_Economics
> 2. Confirm that their home, meter, and electricity contract are compatible.
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.
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?
The battery linked in the article (https://eu.ecoflow.com/products/stream-series-solar-battery) advertises a 15 year lifespan and 10 year warranty. Personally I would expect batteries to last longer than that but 12 years feels fair
> €1,600 for 5 kWh
Those prices are high. You can get 2.56kWh for 270€ on Aliexpress, delivered locally from Germany.
2.56kWh for 270€ on Aliexpress
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.
Most of these are illegal to install in Belgium though. Anything connected there needs national grid type approval.
It this ad from some battery company?
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).
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.
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.
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.
> keep essential devices running when the power goes out
I guess it's very location-specific, but I haven't had a power outage longer than 1 minute in the past 5 years.
You are correct. My area has had 3 in the past 5 months.
The hybrid inverter that allows you to plug the battery into your house circuit (DC -> AC) seamlessly is around $2-3k + installation cost, cause you're touching the main panel. Why isn't that in the calculation?
You plug it into a socket.
Plugging a power-supply into a normal outlet like this is legal in many places, and illegal in many others.
Check local code before proceeding!
Do any US states allow plug in batteries like this (I know some allow plug in solar)? The installation cost of a whole home battery is what has kept me away so far.
That’s a good point. I had assumed the states allowing plug-in solar also allowed batteries, but according to https://pluginsolarguide.com , it’s only Utah so far.
The 12 year payoff IF you manage the arbitrage properly really made me wonder why on earth you would buy one of these.
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 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.
There are numerous systems available for this type of system that are professionally designed and built, and satisfy all kinds of local codes.
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.
A Marstek Venus A 2.12kWh expansion module currently costs 180€ with a bunch of special aliexpress discounts.
The whole system is.. not great, but it's even cheaper to have a battery than this post makes it sound.
How do I properly think about the fire hazard posed by a big battery in my house?
This is what government subsidies/rebates are for - https://news.ycombinator.com/item?id=49298910
Gift should be ... gifts
Welcome to Ukraine where local people installed around 8GWt of batteries at home mostly because of huge outages after missile and ballistic terroristic attacks.
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
You don't really need this, if you have an EV with V2X technology. There's already charging products that work seamlessly: https://www.youtube.com/watch?v=H0WGl_U5azs 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.
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 thing about the EcoFlow Stream is that has things like phase alignment which allows it to be plugged directly into a household outlet without transfer switches to segregate grid phase from the phase of power created by the V2X inverter's phase. It also handles solar input.
I suppose that future V2X systems will incorporate direct plug-in tech, but note the transfer switch used by the system in the video.
> EV battery degradation from this use case is irrelevant.
Nope.
And if you’re in the UK, wire them up to Axle Energy
(plug-in batteries aren’t actually legal here yet, but likely to become so next year!)
The only downside is that the battery won't last 11 years with daily usage
The example prices of kWH in this article are inconsistent
how often do I have to buy a new one? Batteries are one of the highest cost and most consumable items I can think of.
As the post already mentioned, also great for blackouts, of which more are coming for the developed world given climate change and infrastructure failure
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.
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?
>sixteen people contribute €100 each;
yeah sure everyone has 100€ to spend on friends, at least once a month.
What kind of reality does he live in ?
Yeah, at the core it suggests each person lends €1600 (~$1850 USD) distributed in an unofficial and impromptu way, hoping to get it all back as a home-improvement good. That has some implications like:
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...
And everyone lives in a house that they own, apparently.
And everyone makes enough money that something going wrong with their €1600 payment/expectation isn't going to ruin relationships.
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.
Why can't renters plug a battery into their socket, too? As long as the electric house grid is rated for the specified power (might not be the case on some countries, or in extremely old homes).
I'm not an expert. But a Tesla Powerwall type battery is a big thing to install for a renter, is it not? I would argue it's more than installing, say, a washer or window AC; probably more like installing a wall heat pump?
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.
I'm not an expert here, but I don't think you're supposed to backfeed electricity into your panel while you're connected to the grid. Doing something like this (historically at-home solar) you'd need a way to disconnect from the grid physically, at least if you wanted to reuse your home wiring.
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.
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 at all, 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.
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.
I think the people that can easily put aside €100 for the birthdays of a dozen or more friends could also just pay the €1600 and buy the battery for themselves outright without having to wait for a birthday "surprise"
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.
Call me old fashioned, but I just bring a can of gasoline and a pile of super soakers.
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.
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.
In Germany you can use a "Balkonkraftwerk" that just plugs into any outlet and contributes up to 800W. You can also hook up solar panels to it up to 2000W (makes most sense with batteries). No need for the landlord to agree.
Great piece and post, love the concept!
Let's go!
No.