Will these “guerilla solar” units that plug into a receptacle to back-feed get approved for use?
Like, I understand we have the technology to monitor if grid disappears and self-disable, and a lot of hard-wired rooftop solar does that, but unsure if any soft-wired units have been approved.
My fridge is inverter drive and likely operates off DC at its core. Hopefully Samsung or somebody in the future will put a 48VDC port and anyone can plug in a solar panel and it will soak up whatever juice comes off that and use grid for the rest. That avoids batteries (because the fridge does thermal banking), electricians (because 48V is usually excluded), and inverter drive fridges tend to be continuous drive, so running slower when the sun is marginal or full-speed when full works nicely.
And it puts some juice into the thing I really depend on if the power goes out (even if only during the day).
And consumers can cheaply add some phase change materials for a boost in thermal banking (like really salty water bottles).
Put a couple USB charging ports and 12V ports on it too that switch between solar & grid. My router and modem sit on the top of my fridge and use 12V
And then we do away with the increasingly unnecessary DC->AC->DC conversion cycles.
Seems like the lowest hanging fruit to inexpensive mass (mild) solarization.
I always question why we choose between 0kW solar installs OR multi-kW residential installs when we could do massive 250w solar rollouts at low cost with very high efficiency.
> Will these “guerilla solar” units that plug into a receptacle to back-feed get approved for use?
Not practical in the USA with split-phase 120/240 (or 120/208 open wye) as you need to connect to both hot legs of the system to feed everything. In 230V countries they mostly have 2 wire service with (I hear some have three phase 230/400) so its easier to evenly back-feed a 2 wire system.
> I always question why we choose between 0kW solar installs OR multi-kW residential installs ...
Agreed. I have a small home server setup that draws 40W idle and I toyed with the idea of replacing the UPS with a small 1-2kW battery inverter plugged into the wall.
My concern with rogue solar installs is how does that interact with the utility company? Their smart meters will see reverse flow of current and if I do not have an "official" solar install, will they force me to adopt one or disconnect my system as it is not approved? So I would only build a system which draws from the utility as needed (cloudy days) and dumps excess power - never back feed.
> Agreed. I have a small home server setup that draws 40W idle and I toyed with the idea of replacing the UPS with a small 1-2kW battery inverter plugged into the wall.
No idea if this would work in practice, but you might be able to backfeed your battery with a regulated 11.9V onto the 12V lines and backfeed at 4.9V on the 5V lines, so when the power supply shuts off and puts 0V on the 5V and 12V lines, the battery will start back feeding, but when the grids power supply puts out 5V and 12V, no current will move.
(Will need blocking diodes to avoid back-feeding the battery that’s kept topped off by its mains charger)
Saves you some DC->AC->DC conversions. You might need a 3.3V leg as well. And maybe negative voltages if those are used for anything anymore?
I have thought of using a DC-DC ATX supply and eliminate the inverter but I want 120V for other things if needed. But the cost and labor of going DC-DC is higher than DC-AC-DC so the goofy inefficient route it is :-/
It's not the low voltage system you are hoping to see but right now there's a push in Germany to have lots of small photovoltaics systems installed. These setups are called "Balkonkraftwerk" ("balcony power plant") and allow up to 600W (or is it 800W now?) to be feed into mains (via a special plug and receptacle, for safety reason as I assume) without any approval required (you are only required to inform your electricity provider of the fact that you installed one). People renting still need to deal with their landlord of course.
Drawback: any excess power that one does not use oneself is fed into the grid without compensation.
One of the main benefits of having a battery is backup power during outages. You can’t do that safely without adding a breaker between the utility and the house (to avoid backfeeding and killing linemen).
In California, touching a breaker box is at least $10,000, so to amortize the cost of the paperwork, you need to put in a multi kw system. On top of that, you need to anchor it to the ground somehow, so that it doesn’t fly around in 50-100mph winds (which will happen about once during the lifetime of the panels).
Portable systems exist, of course. You could get one of those.
Also, a multi-kw system isn’t physically that big.
Not coincidentally, 240W USB-C is 48V. It'll likely become fairly ubiquitous so I can totally see it becoming the power standard for things where DC is useful, like RV's and off-grid setups. 240W is enough to power a fridge with a slow start compressor.
> Will these “guerilla solar” units that plug into a receptacle to back-feed get approved for use?
They are approved at up to 600 Watts in Germany, and that will probably get increased to 800 Watts soon. You can just plug the inverter output into an outlet. This is called "balcony power plants" here, and lots of municipalties are subsidizing it currently. You can't get net metering, but you can offset some of your load with minimal cost and paperwork.
Why no net metering? Is the output too low to bother? I get net metering is not great for various reasons, but why 'discriminate' against what kind of setup it is?
Sounds reasonable. Here in NL, everyone must get a new smart meter that has a separate counter for delivering back to the grid. IIRC, the grid company replaced it free of cost, if done before some date.
The old ones (Ferraris meter?) just ran backwards, which is attractive of course. Our new meter has a P1 port which can integrate into eg. Home Assistant
> Like, I understand we have the technology to monitor if grid disappears and self-disable, and a lot of hard-wired rooftop solar does that, but unsure if any soft-wired units have been approved.
Would you mind explaining this sentence? I know very little about these things but I'd like to, are you saying that rooftop solar switches itself off if there's no grid power? And if so, why?
Yes, typically rooftop solar doesn't output when the grid is down. If the inverter doesn't get an AC sinus at 60 or 50 Hz, it won't do anything by default. Some systems can, in a so called 'island mode'.
But this is so that they don't supply power when eg an electrician flips a breaker to safely do work. Then better not have the system still energized by solar...
I guess the risk with smaller, plug in systems is that they're simpler without such precautions? And you would have 2 live prongs sticking out, which would be bad of course
There’s a lot of intelligence in a transfer switch that allows island mode - because it has to generate a sine wave when no utility one is present and sync back up with it when one returns.
The cheapest ones just cut power when the sine is lost and then make their own, and cut power when they see it return and then sync.
The much cheaper and covers many/most use cases alternative would be a unit that disconnects anything on-grid, and has some in-unit/on-unit sockets you can use during grid-fail at point of device or run extension cords to.
An issue you may not have considered: if there's enough 250w solar installations to make a regional dent, there's probably enough 250w solar installations to electrify the regional grid sufficiently that the 250w solar installations think there's still utility power and so continue to provide their 250w of solar power to the grid.
My idea doesn’t backfeed to the grid but instead utilizes a load that’s “ON” continuously. Inverter drive fridges can vary their power so they don’t cycle on and off like older fridges with AC motors that only operate at one speed.
Is there even a proper full size DC plug standard suitable for residential use? Besides USB I mean, since USB-C is designed for dainty little gadgets, not full blown appliances.
I find most 12V stuff like modems and routers run off a 2.1mm or 2.5mm barrel jack. (And of course it doesn’t imply 12V). You’d need to bodge a double ended connector.
Maybe screw terminals would be ideal so you can cut your wall wart cable and wire it up. Most devices will have a bridge diode inside (total waste of electricity, but not going there right now).
I guess a cigarette lighter port could make sense but now we might be asking too much on the BoM.
When I say full-size, I mean a plausible NEMA 5-15 replacement exclusively for DC power; something that you could reasonably run at least a kilowatt or two through, and with a mechanically robust design. It should be able to power a toaster oven or stand mixer, and be mechanically robust enough to survive people tripping over the cable many times and being generally rough with it.
Those little barrel jacks are fine for what they are, but I can't imagine powering a toaster oven with one. Cigarette lighter ports might fit the bill, at least mechanically. I haven't seen one of those in many years and forgot about them.
Plenty of options exist in adjacent industries. Stage rigging has a lot of nice stuff for powering lighting/effects (like Neutrik powercon) as does automotive (deutsch dtp or dthd).
Really depends on what kind of amperage you want to run through it.
A kilowatt at 12V is going to be 85 amps and too hot for something rated for 15 amps.
Not sure what’s approved for DC use in general. Standards bodies will probably disagree with using something typically used for AC with DC because of the risk of plugging the wrong thing into it.
Phase change materials are a way to store lots of energy at a given temperature.
You might have noticed how much time it takes to freeze something - that's because lots of energy need to be extracted from liquid water to turn it to ice. And that without even changing temperature - it all happens at 0°C. With other materials, you can have a similiar effect at other temperatures. This can be used to create a system that keeps a certain temperature even if energy flows into or out of it (until the phase transition is complete).
You can do it with hot water too - heat your water to near boiling, and merge it with cold to make the desired temperature. The heater won’t turn on until the temperature drops below a threshold.
Using this you can avoid hearing water during high demand times.
A phase transition can store lots of energy without the inconvenience of changing temperature.
Melting water ice into liquid water at 0°C takes approximately as much energy as heating the same amount of water from 0°C (assuming that it is already/still liquid) to 80°C.
With a material that has a transition temperature of e.g. 21°C, a room could be kept at a very pleasant temperature even when energy is flowing into or out of it.
fun story. I know a guy who designed a high precision refrigerator for storing vaccines. These fridges need to be able to maintain temperature to within some relatively small margin to avoid destroying the vaccines, and they needed to be able to withstand extended periods of no power since they would be stationed in places with questionable infrastructure. The main solution was to use a large water reservoir, it would "store most of the cool" while the power was out, also helped a lot with keeping the temperature stable when there was power.
PG&E offers plans where off-peak rates are substantially cheaper than peak. So, for example, currently Peak rates are 56 cents/kWh while off peak are 25 cents/kWh.[0]
Not sure if the economics will work out, as in a really long ROI for most people, but even without Solar some of these battery packs can potentially time-shift power for homes, reducing effective rate to be the off-peak rate.
56 cents/kWh? Wow, that's shockingly high. Where is this? For context, in the Wllamette Valley in Oregon we're presently paying 15.7 cents fully loaded. Absent regulatory charges, it's only about 13.4 cents. People in Oregon would, I think, riot if energy prices quadrupled. Surprised there's not more noise wherever you are (California?).
It’s strange that these articles compare to power walls, but not the many other competitors on the market.
Tesla has been aggressively doing everything it can to lose in this market. Other options are LG, Enphase and Generac. (Ordered roughly in increasing size of target install.)
These anker units look pretty impressive, based on kWh, but the article doesn’t mention kw.
One problem with enphase is that you can’t keep scaling kwh without also scaling peak amperage, and their biggest distribution bus only supports 40kwh of batteries.
I’ve found Anker’s small batteries to be of high quality. I own a Tesla Powerwall which works well and has nice integrated software and seemed like the best option without a heavy DIY lift as of a few years ago.
Great to see competition here as it will drive more innovation. It will be interesting to see how the software picture will evolve:
Smarter appliances and electric vehicles that talk to the power controller to charge or do more work when there is excess power would be a big level up for these systems.
It's difficult to get large battery packs right. In order to limit the possibility of catastrophic runaway of the pack you have to have extremely robust inter-cell or inter-module thermal isolation and heat rejection. These features are basically non-existent at the handheld power bank scale.
It'll be interesting to see Anker enter this space of large batteries. Either they'll work really well and you'll see them quietly get installed in lots of places, or they'll be in the news when they have a series of runaways and light some balconies on fire.
That being said, a lot of the risk gets taken out with lower charge and discharge currents vs a vehicle application.
I know next to nothing about these but a friend of mine was grumbling the other day about why can't he just use his electric car's huge battery to power his house. It sounded like a great thing? During the day his solar panels charge his car and at night it could power the house (to some extent). I remember him saying something like this is being trialled in Japan maybe? Anyone knows more about this?
That functionality is called "vehicle-to-grid" or V2G sometimes. The F-150 lightning has that capability built in, and there are several companies working to bring devices to market which will act as an interface between the vehicle and your home's electrical panel.
It’s coming soon. Our car’s battery capacity is comparable to the house batteries, so during extended rainy power outages, I’d love to be able to fast charge the car, drive it home, and top off the house battery. (Adding 50% per trip.)
The only other alternative is installing and maintaining a propane generator, but that’s more time then a few round trips into town per year (especially since the grocery store has a fast charger, and we invariably need to purchase food during these events).
Also, they ended up rationing propane this year, since the delivery progress with the big trucks was hampered by road conditions, and demand was unprecedented.
warranty 5 years on this one. theoretically even if breaks 1 day more than 5 years, there is no recourse so why assume it will last 15? tesla offers 10 years warranty on their powerwall so they are confident it will work at least for 10 years.
After about 600 0-100-0 cycles a lithium battery will be down to about 80% capacity, which is enough to trigger a warranty claim. And 600 cycles once a day is only 2 years. Also using the battery at an extremely hot or extremely cold temperature will also reduce its lifetime.
OTOH, if you keep that battery between 20-80% and only use it at indoor temps, you can probably cycle it daily for 20 years.
Climate can be addressed with proper battery management.
For instance, nissan leaf batteries used to die after a few years (I think they fixed this in recent years), but battery failures for other cars of similar age are unheard of.
I wonder if the batteries in India are being produced domestically, and the manufacturers are trying to catch up.
I find their products hit or miss. I've burned through half a dozen of their USB-C to USB 2.0 adapters for my mouse (low power draw, how could it even burn them out?) Thankfully those adapters are dirt cheap, and the other products I've gotten from them have worked fine.
Was going to come say the same. I feel like Anker is just killing it on many dimensions right now. I'm always happy with their products and they're quite innovative, too.
I've liked Anker products, starting with being able to get quality batteries for older laptops and handhelds. Today, I'll lean towards the Anker brand for any product, when I see it in Amazon search hits (amidst the hundred random-brand-spam listings for the same cheap product, and the handful of hits for real brands likely commingled with counterfeits).
If it turns out that Anker only made the mistake of hiring a stereotypical criminally-negligent/insidious IoT product team, then healing could begin by Anker dragging every person responsible out to the parking lot, and telling them to go defecate on some other brand. Because the value of Anker is trustworthiness.
They're very high on my trust-o-meter too. Never bought a bad product from them, and if someone asks me a question that should really have a very long and boring answer like "which USB-C cable should I buy?" I tend to just tell them to buy Anker.
> In Germany [...] Just plug Anker’s inverter directly into any standard home power socket to feed energy back to your appliances with any excess diverted to the battery.
That's legal?
In the US, at least for generators, it is illegal in most jurisdictions to do that. You have to add a transfer switch that disconnects your house from the grid before you supply non-grid power to your house wiring.
That's so people's generators won't energize the lines that the linesmen are trying to fix during a power outage.
I might be about to wade into solar for my place (So Cal). But home equipment reviews on the Internet are..mixed at best. How to evaluate what's the latest/greatest and most reliable, etc? Tesla has the biggest name but reports of support post-install are...mixed at best.
Thanks to NEM 3, you will want batteries. Find an installer that has been around for 5-10 years, and that has a good reputation. Even the best equipment can be installed improperly, and the installs are complicated. (You wouldn’t rewire a house by first choosing the brand of circuit breakers and outlets; instead, you’d pick a good electrician, then follow their advice).
Different equipment brands specialize in different types of installations, so I won’t recommend anything without more information.
But does it spy on you? I investigated solar installs for a bit where I live, and out of the two main bids, both of them required an Internet connection at install time, and one of them required a persistent connection. This is horrendous.
> now European apartment and condo dwellers can get in on home energy storage by sacrificing the walk-out space that was totally worth the extra monthly rent or mortgage.
These battery + solar controller + inverter all-in-one things are very overpriced. You can DIY one for 1/4th of the price, with better components, and learn something along the way. I will say the software/apps they come with can be nice.
I'm in this camp and looking into DIY. I'm in MA. I get installers stopping by all the time because I have great roof space... but the orientation is horrible for solar so it ends up being a super expensive system that is losing half of its effectiveness because of roof orientation.
So I've been looking into DIY my own "small system" on a spot that is oriented perfectly. Problem is I can only get like 2KW worth of panels. Too small of a job for an installer but even more perfectly suited for a DIY project.
I know reddit is a dicey topic these days but found the r/DIYSolar to be a useful sub to ask questions and get great answers and/or clarification as to where to look for answers.
These also store a lot of energy and can burn your house down. If you know what you're doing sure, but your home owners insurance might have something to say if it is the cause of a fire.
We need as many options so that this market can get jump started. My risk adverse brain wins out over my nerd brain on this one. I love the idea but want a professional product that isn’t priced by space karen so affordability can increase.
LiFePO4 batteries can help in that respect - they also have superior cycle life. I wouldn't jump into an entire home solar setup as a noob, but a simple 100w panel with a small battery can be fun and accessible.
Maybe Europe is different, but in Canada (and maybe US), you often don’t own your condo balcony. You get exclusive use of it, which means the HOA/condo corp/strata gets a lot of say in what you can or can’t have on it.
My Canadian province doesn't allow battery storage in homes. At best if you have a garage you can put one there but other than that no other choice. Outside is not an option since it gets to -20C here in the winter.
One local person spent thousands of dollars only to find that out. The electrician and province should be sued by the homeowner for lack of info and lost money.
Heated sheds are not common here. Most if not all don't have any power. I guess if batteries were in it then it could heat using the same batteries.
But you'd still need to run a line from the shed to the house anyway to distribute the power. Minimum three feet deep the correct gauge and encased in the appropriate conduit sent to a subpanel then the main panel.
Honestly, if you can do this, you should start a lifestyle business. You could undercut the incumbents by 25% and still have a 66% profit margin, which is insanely good.
I don’t think the power companies like it when you feed power into a system like that (basing off their balcony solution). Definitely curious how their solution ends up costing though.
Like, I understand we have the technology to monitor if grid disappears and self-disable, and a lot of hard-wired rooftop solar does that, but unsure if any soft-wired units have been approved.
My fridge is inverter drive and likely operates off DC at its core. Hopefully Samsung or somebody in the future will put a 48VDC port and anyone can plug in a solar panel and it will soak up whatever juice comes off that and use grid for the rest. That avoids batteries (because the fridge does thermal banking), electricians (because 48V is usually excluded), and inverter drive fridges tend to be continuous drive, so running slower when the sun is marginal or full-speed when full works nicely.
And it puts some juice into the thing I really depend on if the power goes out (even if only during the day).
And consumers can cheaply add some phase change materials for a boost in thermal banking (like really salty water bottles).
Put a couple USB charging ports and 12V ports on it too that switch between solar & grid. My router and modem sit on the top of my fridge and use 12V
And then we do away with the increasingly unnecessary DC->AC->DC conversion cycles.
Seems like the lowest hanging fruit to inexpensive mass (mild) solarization.
I always question why we choose between 0kW solar installs OR multi-kW residential installs when we could do massive 250w solar rollouts at low cost with very high efficiency.