17 comments

  • chris222 1 hour ago
    Bluetti already has a product for this available in the EU. I have been posting eveywhere that they need to bring it to the US.

    https://www.bluettipower.eu/products/balco-transfer-hub

    Balcony solar without storage is actually pretty dumb when we already have integrated battery/inverter/solar mppt units available for a few hundred dollars.

    All we need to do is have something like this hub inbetween to ensure grid isolation when an outage occurs.

    For crticial loads you would just plug those directly into the all in one battery unit. Almost all of them these day also have a <20ms UPS pass through function as well. When the grid goes down it can isolate the battery from backfeeding the house but the solar will still function and the critical loads will still function.

    With a solution like Pila is developing you could even use your homes wiring to transfer power (~1kW) around multiple small battery units (attached to independent circuits) each with some different critical loads and solar attached to them.

  • Animats 39 minutes ago
    There are several variations on this idea, and the web sites are confusing.

    First, there are ones that are just a big UPS. You plug them into the wall, and plug loads into them. They may try to level your power usage. No problem with that. Good for refrigerators. That seems to be what "Pila" is selling. This class of device seems to come with deceptive ads which do not show cords from loads plugged into the box.

    Then there are ones that purport to pump power back into their wall outlet. That has safety issues, starting with its male power plug being an output. It can't provide power when there's no input power, because it would try to drive the the whole grid during an outage. It's mostly for taking advantage of variable power pricing. This seems to be what "Regen" is selling.

    These are apparently available in Germany, but must be installed on their own dedicated circuit, so you don't have a load and a source on the same side of the breaker. Otherwise, you could potentially have an overload without a breaker trip. Regen is trying to get them into the UK, but old UK ring main wiring is a bad match to this. Gotta have a breaker between load and source.

    The trouble with these things is that, plugged into the wrong outlet, they create a gap in overload protection that won't show up until something goes wrong.

  • reenorap 1 hour ago
    Why bother? Power companies will complain they are losing money and regulators will allow them to buy energy from residential solar panels basically for free (NEM 3.0). This is California.

    California has spent decades convincing people to convert to solar panels and EVs and now that many have switched, they doubled electricity prices and told us not to charge when it’s too hot. Now they want solar panel owners to pay a surcharge for “connecting to the grid”, upwards of $100/month or more than my actual solar bill. It’s all a scam.

    • mkozlows 1 hour ago
      It's not a scam. Connecting to the grid has enormous value, and keeping the grid up has real costs. A model where your generation pays you retail prices doesn't make sense.

      California's current net metering system, which is more reflective of the true benefits and costs of solar to the power system, has been incentivizing people to add storage to keep their solar rather than get paid big money to feed back midday low-value solar, which is a big win.

      • zugi 1 hour ago
        > Connecting to the grid has enormous value

        Yet in most locales it's illegal to disconnect from the grid.

        If disconnection were legal for those who want to be energy self-sufficient, then charging just to connect would be more defensible.

        • bsder 55 minutes ago
          > Yet in most locales it's illegal to disconnect from the grid.

          That's kind of ... required?

          Otherwise you have a bunch of people who are off the grid until the sun doesn't shine for a week and they run their batteries down and then they all try to connect simultaneously and collapse your grid.

          Most places I know of don't care if you never connect to the grid--you get your exemption and get on with life.

          However, once you are connected to the grid even once, the grid operator has to size things for the worst case when everybody is connected to the grid and drawing power and work things out for stability when everybody disconnects and they have to back off generation. At that point, the grid operator is well within their rights to demand that you comply with cooperative regulations like making a request to connect/disconnect from the grid itself.

          • labcomputer 48 minutes ago
            Are you being deliberately obtuse?

            It is illegal to discontinue your relationship with your local electrical utility. As in, completely disconnect from the grid, cut the wires and never look back.

            As the previous poster said, charging for the “privilege” of connecting to the enormously-valuable grid would be a little bit defensible if having a connection were not legally required in most places.

            • hparadiz 6 minutes ago
              You know I can just not use that grid electricity, pay the absolute minimum, and then do everything off grid right?
            • DANmode 6 minutes ago
              Depending on jurisdiction.

              This is not ubiquitous. It is common.

      • perpetuallunch 45 minutes ago
        Since all we’re doing is opinions, and all opinions are equal.

        It’s a scam.

        All that money we’re coughing up for rooftop solar and batteries at home would be better spent investing in grid scale electricity generation, of any technology.

        That way the best ideas generate more profit than the lesser ideas, and market discovery can solve problems.

        Maybe governments could incentivise renters and home owners alike by discounting tax liabilities on new power generation investments. Or share holders could be offered discount rates. I’m open to ideas.

        Rather than government picking winners, which seems to have a terrible track record.

        Therefore, I posit my opinion is more valuable than yours.

        • mullingitover 15 minutes ago
          > All that money we’re coughing up for rooftop solar and batteries at home would be better spent investing in grid scale electricity generation, of any technology.

          In my city we literally can't buy any more grid scale solar. We rely on the county for transmission, we're buying all we can, and we're maxed. So you either get solar installed or you're paying some of the highest rates for electricity in the country.

          I'm installing the max balcony solar the law allows the day it's legal. It's the biggest no-brainer every, it'll pay itself off in ~2 years in my case because it's knocking out the most expensive part of my power bill.

    • pkulak 7 minutes ago
      If being connected to the grid is a "scam", then disconnect. Buy 100 grand worth of batteries (which still may not get you through the winter), and pull the ol' plug.
    • jampa 1 hour ago
      The new rule here requires you to pay for part of your imports (up to ~60%), even if you export more. I know people who installed batteries in the inverters because of this. It is more expensive overall (hybrid inverter + LFP batteries) but has other benefits (blackouts are not a problem, most months you don't even use the grid). I imagine that once sodium-ion battery production scales and costs decline, this will become the "default" option for a solar installation.
    • perpetuallunch 58 minutes ago
      Similarly here in Australia.

      Electricity prices keep increasing, daily supply charge keeps increasing (this ones supposed to pay for the transmission network), while the solar feed-in tariff keeps decreasing.

      With the added stupidity that, obviously the sun works during the day and so do you.

      Now tax payers are forced to subsidies residential batteries as well as rooftop solar, which results in a wealth transfer from everyone else to home owners, and isn’t a policy that helps low income earners and / or renters.

      It’s also government picking winners, which historically has never worked, rather than letting private enterprise pick winners, and potentially failing, in an open and free market.

      Wild.

      • chris222 52 minutes ago
        Australia has been a great success for solar and battery storage.

        Your statement about a wealth transfer is putting no value on climate change or good air quality which benefits all.

        • perpetuallunch 13 minutes ago
          No it hasn’t.

          What it has done is resulted in ridiculously high electricity prices, such that manufacturing anything in this country has become progressively less viable.

          The Net Zero story sold to Australians is, and always was always will be, complete bs, as evidenced by three facts:

          1) It’s no longer the narrative, because “data centres”

          and

          2) even when it was the narrative, it was always bs because Australia exports huge amounts of gas, and a metric ship load of coal, so other countries can have affordable electricity. So why don’t we just use it. There’s only one atmosphere.

          and

          3) Australia could double or triple its emissions and it would have approximately no additional impact on total atmospheric carbon dioxide concentrations.

          We haven’t reduced our emissions, we’ve merely exported them.

          In before you say “shut up Pauline”, yes I did vote One Nation at the last federal election.

          And if you’re so sure I’m just drowning in koolaid, how certain are you you aren’t?

          Remember the good old days when governments weren’t to be trusted and we criticised them when they laid out idiotic policy?

          • vvbull 1 minute ago
            Australia emits 1-1.5% of greenhouse gases. Tripling that would absolutely impact global concentrations, especially over human time scales.

            But agree, Australia exporting fossil fuels should be reflected. If you counted their export of fuels it would be closer to 5% of global emissions.

            IMO, getting to zero would knock over a whole integer percent off the global goal, that's notable. And if you stopped exporting oil, we'd be 1/20th of the way to the goal already!

      • theshackleford 33 minutes ago
        > Wild

        Calm down Murdoch.

        • perpetuallunch 12 minutes ago
          Very convincing argument.

          Thank you for your contribution.

    • Aurornis 1 hour ago
      In more well-run locations, power companies are providing incentives to install batteries because they help reduce the load on the grid.

      These are plug-in solutions, though. The whole idea is that a permit isn’t required. If approved in your area, you don’t need to work with the power company at all. You just buy one and plug it in.

      The plug-in stuff doesn’t play by the same rules as the big installs.

      • skew-aberration 1 hour ago
        Yes, and non plugin-in batteries don't just need a permit - typically the power company also directly controls the battery, via a web API that the manufacturer provides (at least in Australia, this is a condition for access to the incentives).
    • labcomputer 36 minutes ago
      > Why bother? Power companies will complain they are losing money and regulators will allow them to buy energy from residential solar panels basically for free (NEM 3.0).

      The way I would see this working is that you charge the batteries when electricity is cheap (generally, midnight through early afternoon), and then run the house (not supply the grid) the rest of the time.

      LFPs are cheap enough now that a strategy like this would pay back after about 2 years.

      If they try to adapt with a “NEM 4.0”, the whole thing will collapse because solar and LFPs are so cheap that everyone will just pay their mandatory $50/month grid connection fee and not buy any electricity from the grid.

    • appplication 1 hour ago
      The solar situation in CA is truly mind boggling for a state that is ostensibly progressive.
      • labcomputer 43 minutes ago
        It’s not just solar.

        Property taxes increase at a rate legally-mandated to be less than inflation. Not just that, you can inherit your parents (or grandparents) property tax rate.

        Didn’t have parents who owned property in 1978 (shortly after racial covenants were declared unconstitutional)? Well, why don’t you just go fuck yourself?

        Everywhere you look are policies that are ostensibly progressive, but actually quite regressive.

        • hparadiz 8 minutes ago
          That doesn't really matter when you're buying a house in CA. It's a relatively small percentage of a difference in my overall mortgage. I'd rather have Prop 13 even if that means some people inherit a tax break. Homes that stay in a family have less administrative churn and keep neighborhoods more stable in the long term.
    • thelastgallon 1 hour ago
      Completely agree with you, Govts sacred duty is to protect the super rich and utilities are the biggest monopolized cash cows (Eg: Warren Buffet). However,if people work with their local governments and change the building code to allow plug-in solar and plug-in batteries, that will continuously upgrade every home to become more and more energy independent and with the explosion of products, eventually be grid free. The biggest costs are labor, permits and delays; if its just products that people can plug and play, the adoption will be faster than just rooftop solar (or rooftop + batteries).

      Also, most utilities have tiered rates (higher utilization at higher rates), if you can have plug in systems that can bring the total kwh down, it immediately lowers the peak rate.

      The only bottleneck is making products that are safe to plug in, and this will happen as building code creates a standard to plug-in.

      • alwa 34 minutes ago
        So… @lazide replied with a hahaha. It got flagged to death, understandably.

        If it were anybody but @lazide I’d have flagged it too, but… I can’t help but grimace and nod.

        To hazard a somewhat-informed guess at their subtext… and politely ignoring your opening salvo of calorie-free populism… there seem to be elements of “not even wrong” here.

        * code, especially in the huge fundamental aspects, tends to flow from the NEC downward, rather than from municipal experiments in playing with literal fire. Not insurmountable, I guess, but it seems like a pretty big chicken-and-egg kind of obstacle to your proposed course of action;

        * individual household demand is several orders of magnitude removed from the considerations informing grid design and operations;

        * the last thing a grid needs is a meaningful amount of random feed-in that it can’t centrally (and near-instantly) manage;

        * the costs of home-scale labor/permits/whatever are only the biggest ones from the perspective of toting up individual homeowners considering uneconomical projects, not from utility-scale (much less whole-polity-scale) scratchwork… would an army of volunteer homeowners’ labor really still outperform specialist labor installing hundreds-of-homes’ worth of capacity per day at an energy facility somewhere?

        * the thing holding back the “explosion of products,” consumerist-salvation overtones aside, seems more likely to be {physics vs the existing built environment} than permits—that, plus the lack of a mass market;

        * one barrier to “plug and play” is that said plugs are safe only because of an interlocking set of assumptions upstream of said plugs—which definitely do not contemplate feeding back in whole-home current from a random convenience outlet on your front porch;

        * Rate tiers are an economic device to influence consumption patterns under the status quo. As the Californians are learning, there’s a hard floor on the price of “having a grid” vs “not having a grid”; as consumption patterns shift, rate schemes can and must shift too;

        * building codes care about safety, grids and ISOs and energy providers care about capacity and stability. Players on grids can realize enormous economies of scale with respect to pretty much any generation or storage technology. The bottleneck you describe is…

        I dunno, man… the only bottleneck to energy too cheap to meter is fusion, obviously all we have to do is just go crack fusion and put a fusion pot on every stove!

        If my grandmother had wheels she’d be a bicycle. I love your sense of empowerment; I’d encourage you to bring it to bear at a scale where it matters— much bigger than a home, much smaller than a whole polity… I think there are benefits to decentralization and to independence but I don’t think those are the benefits you’re emphasizing here.

      • lazide 1 hour ago
        [flagged]
    • dghlsakjg 1 hour ago
      These are problems not inherent to solar, but to places that are underdeveloped and under-regulated.

      Plenty of places in modern and developing countries don’t have these issues.

    • searealist 1 hour ago
      NEM 3.0 is more fair. The grid is expensive and just as expensive if it is needed to be fully utilized 1% of the time or 100% of the time.

      The problem is California forcing new construction to buy overpriced solar from builders that makes little sense compared to commercial solar installations + grid.

    • fortran77 1 hour ago
      When we got our solar system in CA, our electric bill went to zero. We calculated the payback to be 9 years. Eventually, they stopped buying back electricity and changed the way they metered and our bill was as high as ever. We save a bit because we're able to charge our electric car at times of peak PV output.

      We left California last year for this and many other reasons. They just don't want anyone to be productive here.

      • chris222 50 minutes ago
        Dishonest post. When you bought your system you were grandfathered into either NEM 1 or NEM 2. Please provide proof that your arrangement changed.
        • hparadiz 5 minutes ago
          NEM 2.0 doesn't pay as much anymore but that could just be increased grid electricity costs.
      • aaomidi 51 minutes ago
        Literally one of the most productive states of the entire world btw
  • satiric 51 minutes ago
    Plugs and sockets have the wrong gender for this. On the battery, you'd have a male plug with live 240v contacts, ready to short against anything, or anyone, that's conductive. This is the same reason why male-to-male extension cords are labeled "suicide cords".
  • kazinator 30 minutes ago
    If "everyone" uses plug-in batteries, the peak demand curve will be flattened and the utility companies will likewise flatten the rate. Then there goes the arbitrage; everyone is left with just an expensive piece of emergency equipment for blackouts.
  • tempestn 1 hour ago
    I assume plug-in batteries are considerably more workable in the UK on 240V, since they could charge and deploy at double the rate of a plug-in system here. Of course 240V plugs exist in North America, but they're generally only installed for dryers, ranges, and EV chargers, so people don't tend to have one just free.
    • NavinF 1 hour ago
      What percentage of buyers do you imagine are gonna buy a battery big enough to saturate 15A*120V=1800W for long? The average home uses 30 kWh per day = 1250W. Batteries don't need to handle peak load. Approximately nobody has a whole home UPS.

      Also 240V power strips are fairly common in my circles because GPU server PSUs tend to be more efficient at 240V. They're marketed as PDUs, not strips. You're not gonna install a new outlet for every server. One dryer outlet in the garage is enough for most people

      • labcomputer 28 minutes ago
        > What percentage of buyers do you imagine are gonna buy a battery big enough to saturate 15A*120V=1800W for long?

        You can get 10kWh of batteries and a 5kW MPPT chargeverter for a little over $2k these days (UL certified). A 30 kWh system with inverter can be had for around $4k. That’s well within the reach of most households.

      • tempestn 50 minutes ago
        I'm not clear what point you're making about PDUs.

        Re 120V outlets, while batteries don't need to supply the full peak load, they are more effective the more of it they can supply. And a home with a heat pump or baseboard heaters, electric range, EV charger, or dryer for example is going to at times significantly exceed the capacity of the 120/15 outlet. Doesn't mean the battery would be useless, just that it wouldn't be as effective at its primary purpose of load shifting as a 240V system, and therefore less economical.

    • Scoundreller 48 minutes ago
      What makes it easier on 240v systems is that your entire household is on the same “circuit”.

      If you’re on a 120v system, there’s a ~50/50 chance that your load is on the wrong side (except for 240v loads where you’ll imbalance things a tad but it should average out).

      Unless you’re in an apartment/conso and have 208v instead of 240v… dunno what happens then.

      • Symbiote 3 minutes ago
        [delayed]
      • bob1029 23 minutes ago
        Every US household has at least some big circuits across both lives. You could theoretically put the battery in the laundry room and use the 240v outlet. This is effectively what I did when my power was out during a hurricane. I backfed my entire house through my laundry room. Not to code but nothing was that week. The circuit wasn't rated for enough to handle the HVAC load so I eventually installed a separate 50A inlet on the side of the house.
  • shusaku 59 minutes ago
    As someone with a poor background in electrical engineering, this is really cool. It’s amazing that you guys can make something like this work.
  • yhcehb38r 55 minutes ago
    UK-based reader here. Homeowner, with no solar or battery, but interested in getting some decent, independent advice, how would I go about it?

    We are a two EV household, with oil central heating. Don’t mind paying for solid unbiased advice.

  • guidedlight 1 hour ago
    I thought plug-in solar was coming 10+ years ago.
    • internetter 1 hour ago
      Millions of households have plug-in solar. The payoff is something like 1.5-5 years. Of course, this should be tens or hundreds of millions, but this isn’t vaporware
  • hkt 43 minutes ago
    I've been following this for a while: Regen have a beautifully designed product. The idea that people need to be able to access time of use tariffs in a way that yields lower energy costs makes a lot of sense. But this is about energy costs rather than infrastructure, and the actual problem is that products like this are a) a bit scary to have indoors and b) a hack to compensate for deficiencies in the UK energy market.

    I'm also a member of the lovely https://kirkhillcoop.org/ - an energy coop. I own around 1kW of potential overall production from a number of pretty big turbines in southern Scotland, for which I paid around £1k. The benefit to me is I pay opex cost for energy according to the performance of that farm. I believe this is projected at around 5p per kWh - we're getting our first payouts this year.

    The coop model means I don't need anything in my house. It is also, sadly, not accessible because of companies like Ripple Energy collapsing. They facilitated the coop being started in the first place. No more of them can be founded. Starting these things in the first place was just too hard and too slow.

    Whereas batteries.. are an incentive to use domestic headroom to balance the grid at considerably lower costs than if a commercial operator did it. High costs generally mean time of use tariffs give an incentive to people to do what ought to be grid scale investments, but there's the problem: the only way individuals can capture the benefits of grid scale investment is via specially designed shareholdings in those investments.

    Nobody is offering that chance now that ripple is gone. Buy shares in companies operating wind turbines, or retail energy suppliers, and your gains are so much worse than with a Ripple co-op like Kirk Hill. They're worse than a battery, too.

    I'll be getting a plug in battery when the time comes, but it is truly insane that I have to personally take on that responsibility to feel the benefit, and that there is no easy route to buying at grid scale. Ripple were a very brief oddity I'll derive a small benefit from for a long time, but now they're gone, and all we have instead is the prospect of storing pretty scary substances in our homes instead, on time of use tariffs which also don't let us reap the full benefit from our investment. It sucks. Cooperativism and mutualism would be a nicer alternative.

  • luxuryballs 1 hour ago
    Wild that we have to ask permission to be able to make this stuff.
    • dghlsakjg 1 hour ago
      The power grid has the potential to be insanely dangerous. We largely have eliminated that danger because of tight regulations and codes.

      Look up backfeeding, which is a huge concern with this stuff. It is entirely possible for anyone sharing a transformer with you to send power back up the lines to your house in a dangerous way. That’s why you shouldn’t just plug a generator in with a suicide plug when the power’s out.

      A grid tied battery without the right protections is electrically identical to a generator with a suicide plug. We want some standards here.

    • Aurornis 1 hour ago
      Not really. If it was off grid it wouldn’t be a problem, but connecting to the grid requires that all of the power generating equipment get along and operate safely.

      Anything that starts getting into shared territory requires regulations. Similar to how wireless equipment needs to comply with regulations so we can use the frequency spectrum.

  • wang_li 1 hour ago
    If one is not modifying the house wiring how does this prevent backflow into the grid? Does it shutdown completely on power loss from the mains?
    • eleventen 1 hour ago
      The standard governing this is UL 1741 in the US or VDE-AR-N 4105 in the EU. both require certified inverters to detect grid loss and immediately cut off.
    • trial3 1 hour ago
      yeah, it’s called anti-islanding. UL 3700 is the thing to look at if you want to read more about some of the safety precautions
  • slackfan 1 hour ago
    This will lead to some new and exciting ways of starting a housefire.
    • alexjurkiewicz 1 hour ago
      How many houses in Britain have wiring that is less than 800 W away from starting a fire? How many of those houses have the disposable income to buy a plug in battery?

      Yes, more electricity means more risk of fire. But 800W batteries do not seem like a major safety issue

    • xbmcuser 1 hour ago
      The new sodium batteries are a lot safer than the lithium chemistries. And we already do have type of home batteries they are just called UPS systems. The real game changer will be when 3-5kwh plugin batteries fall below $150-200pkwh as at those prices batteries will make sense even for apartment owners/renters with no solar to use it to demand shift as time of day electricity prices get more common.
      • hkt 1 hour ago
        Why that number in particular? Are you thinking of payback period of something else?
        • xbmcuser 53 minutes ago
          Yes payback period batteries as at those prices payback period falls below 5 years with just 4-5c arbitrage so even if you don't have solar like most apartments it is still useful. And the price is low enough that it can be made mandatory for all new home construction without inflating home prices.
    • kibwen 1 hour ago
      While the potential for fires shouldn't be dismissed, for batteries designed to be stationary rather than mobile (such as in an e-bike), you can use a chemistry optimized for stability rather than optimizing for compact weight and size.
  • cyberax 1 hour ago
    Why? Just make it possible to buy "shares" in a larger battery bank, if you must.

    Home batteries make total sense for off-grid systems or as a backup power source. But plug-in batteries are not designed to do either.

  • lukeify 1 hour ago
    I can’t help feel without ampacity and voltage upgrades to most domestic home circuits this is like a fart in the wind.
  • My_Name 1 hour ago
    "the battery pays back from around 2.5 years onwards"

    So around 1000 charge/discharge cycles?

    That is roughly the ability of a battery. By the time you break even, it's time to spend again.

    • 0xR1CK 52 minutes ago
      LiFePO4 batteries generally sit upwards of 3000-8000 cycles to 80 percent original charge.... Depends on what your chemistry is.

      As the batteries improve, you'll probably want to upgrade every 8-10 years or add/swap out a 1/4 to 1/2 storage by that time, still able to use effectively even if a little lower top end. Depends on your usage and if you're still on grid.

    • protimewaster 55 minutes ago
      I assume these would be batteries that are relatively robust in terms of cycle count, like LiFePO4.
    • jauntywundrkind 50 minutes ago
      Lithium irons are often 4000 cycle now. For full cycles.

      I forget who but I really want to say I was looking at some cells a year or three ago that were 10k cycle count.

      And it's not like the battery is worthless at that point. It just means the battery is down to 80% max capacity. You can down cycle it, find some other consumer to use it, replace it, if you need the capacity. But should keep running for a long time.

  • pudgywalsh 1 hour ago
    What was the breaking point for modern British society where housing unwieldy and potentially hazardous electrical equipment in your living room seems like a completely normal and just thing to do?
    • slyall 1 hour ago
      I guess you've never come across electric heaters or if you want to go into the bedroom electric blankets ( 5000 fires per year in the UK in 2011 )
    • hkt 1 hour ago
      Presumably it helps that these things have their own fire suppression systems, time of use tariffs are cheap, and everybody needs a win.

      (I'll be putting mine outside)