Discussion
The Libre Solar Project
danw1979: > Unless stated otherwise, none of the published devices has passed regulatory certification, so use them at your own risk and responsibilityThis somewhat limits the usefulness of the hardware anywhere you need to be insured, e.g. your house, boat or van.
fred_is_fred: How hard is it to get stuff certified by UL? I would assume expensive and time consuming but don't really know.
aeblyve: I don't know much about UL but I can say that FCC certification (also technically required) for electronics can range from about $3k to something like $30k depending on what you're doing.($3k would be for "unintentional radiator" device, i.e., not supposed to be a radio, $30k would be for "intentional radiator" device, i.e., supposed to be a radio)
Joel_Mckay: Because of customs product import rules, that FCC stamp is often not optional. Now if it was a dodgy seller, the stamp will not match the physical devices on rare occasion. =3
Joel_Mckay: In general, almost all insurance companies will demand UL stamped hardware, and most mortgage/lease/commercial property requires insurance.A hobby BMS is usually a bad idea, as most kits from unknown origins prioritized cost over safety. Depending where you live, prior to roof installation there may be additional zoning and signed engineering drawing requirements.It is not hard to find UL equipment, but expect to pay about another $600 for the BMS. Yet, it is better than a house burning down, and the insurance provider denying coverage.Have a look at local certified installer companies, and make sure to get some real references in your town. Just like most HVAC companies... some installers are just over priced scams. Best regards =3
jacquesm: This is a very nice development, but it is tackling the easy stuff. I'd love to see an open source inverter that can operate in stand-alone mode or in grid connected mode. All of these grid connected devices with closed source are a massive risk, especially given how small and cheap a WiFi or cell modem is nowadays.
Rebelgecko: Deye/Solark famously bricked a bunch of inverters remotely not long back
boringg: Glad to hear it - but cost of renewable energy isn't the software or hardware locked behind vendors. Its installers, wholesalers and permitting. Pricing is set to about where homeowners will be willing to pay and installers will make a good profit. If only it was a 5 year payback - we'd see it everywhere in NA.
progbits: Not sure cost saving is the priority.I got solar installed by the local power company and while it's well done and was a great deal regarding the price, the inverter stats are locked behind a really terrible app. At least there isn't a subscription cost but I wouldn't be surprised if they add one someday.Would gladly pay more for fully open and serviceable replacement.
jacquesm: I opened up all inverters here and disabled all remote access hardware physically. I'd rather not have a warranty than the risk of either seeing my critical hardware hacked or bricked by the manufacturer. And given the size of these (one is a 17KW unit) the risk of real damage to my home circuits and/or the feed is not imaginary, just rapidly turning it off and back on would already be a big problem, especially on a really sunny day. I try everything I can to not trip the breakers on the inverter around solar noon on sunny days because the amount of current is non-trivial, even on a 960V system. It will generate an absolutely spectacular arc.
westurner: Why ZephyrOS?ZephyrOS: https://github.com/zephyrproject-rtos/zephyrWould there be value in modeling this system with TLA+?Why build another open product?There are a few GitHub topics for solar electricity:solar: https://github.com/topics/solarphotovoltaic: https://github.com/topics/photovoltaicpv: https://github.com/topics/pvbattery-management: https://github.com/topics/battery-managementups-management: https://github.com/topics/ups-managementinverter: https://github.com/topics/inverterPhotovoltaic system: https://en.wikipedia.org/wiki/Photovoltaic_system
bityard: > Why ZephyrOS?They say right here: https://libre.solar/software/
lentil_soup: A meta comment and really don't want to distract from the product but as a Spanish speaker, the word "libre" for open source projects really grids my gears. It's specially bad when used with "libre" before the subject (like LibreOffice or Libre Solar). It sounds a bit like Brad Pitt saying "bonjourno" in Inglourious Basterds.Libre does mean free as in freedom, but it also means available and released from prison.
jacquesm: It's from French, not from Spanish, and besides, everybody knows what the intentions are here so I don't think you need to feel offended in any way, that's your choice.
martinjaeger: That's basically what most software Open Sorce projects state in their licenses as well: Use at your own risk. As someone who publishes design files openly you really don't want to be liable if someone uses the hardware in a wrong way.That being said, the Libre Solar components are also meant to be used as the basis for customization (hence, called building blocks). Some of the devices are used with minor modifications in certified commercial products.Apart from boats/caravans, DC systems are used a lot for rural electrification in the global south. This is also where the communication features of Zephyr RTOS are very important.
boringg: I get that - but also solar should be cheap. If we lower the cost of power we knock off a lot of the bad externalities of power production and allow people to be more inventive with their power use.Agreed - a lot of the inverters do some real BS moves around data management clearly a way to extract more value in a subscription mode. Its mind numbingly frustrating.
SoftTalker: Price isn't determined by the cost of supply but by the value provided to the buyer.
bityard: This is for DIYers and enthusiasts, not someone looking for an off-the-shelf box.(Also, Amazon is where most people get their solar equipment these days and you would be amazed how much of it is not UL certified either.)
ktm5j: DIYers and enthusiasts should still worry about their house burning down because one of these boards started a fire. An insurance company would investigate and find any excuse they can to deny payment.
lentil_soup: chill, I'm not offended, just thought it was worth mentioning it sounds bad to native speakers. Wouldn't you mention it if someone was misusing a Dutch word?Also, it comes from French and Spanish [https://www.gnu.org/philosophy/free-sw.en.html], it's the same word and same grammar, subject before adjective.
bityard: They are pretty clearly targeting DIYers and enthusiasts who like tinkering with off-grid solar.Grid-connected is an entirely different ball game. You will not see any open source projects there, or at least not any that anyone will want to use.Let's think about why not. Anything grid-connected, you REALLY want a licensed electrician to plan and install. And competent electricians will NOT go anywhere near a piece of equipment that is not UL certified. A company producing equipment is NOT going to go through the expense of getting UL certified and then just release their design, PCB, and schematics for free.And I want to be clear that I am a strong proponent of open source hardware, there are just certain situations where the incentives in reality just don't line up. This is one of them.
repparw: Could the inverse process work? Design, then (crowdsource?) pay for UL certs? Don't know the process for certification, but in the software side, I've heard from foss projects asking for money for, e.g, security audits
Dan_-: Should is doing a lot of work there. The reality is most don’t. These are people who don’t understand minimum conductor size trying to DIY a solar system.
jacquesm: Bollocks. I've been making grid connected hardware for decades, there is nothing magical about any of that. You just need to be careful, use proper fusing and you need to know how to read the electrical code.Competent electricians are licensed professionals who (1) stand to make money on selling gear and (2) have customers that hire them simply because they don't want the hassle or the liability. Obviously a licensed professional is not going to install your home brew inverter, but at the same time if you can design a homebrew inverter you probably don't need a licensed professional anyway.I've rewired lots of homes and have never had an issue with any of this and designed my first inverter when I was 17 to power my room when my betters decided I should go to sleep and cut the power.This stuff is not magic. If someone designs a modern open source inverter I'm definitely going to build and install it. Fortunately insurance companies here are reasonable: if your homebrew device wasn't the cause of the mishap then you are still insured.The one thing they are very strict about is gas, because there is no such thing as a 'fuse for gas'. But if you've properly designed and fused your gear then it should be no less safe than any other grid connected device, even if the magic UL or TUV mark isn't there.The big one is EMI, that can be hard to get right and you need some gear for this, which is why it pays off to pool the money for an open source design to be certified. And once certified of course the design is 'type approved' and frozen, so you can't change any of the hardware without going through recertification. This is expensive, but if you don't do it every other week should still be well within the means of a properly set up open source project.Why the fearmongering? It's not as if we're 12 here.
hn_acc1: >Bollocks. I've been making grid connected hardware for decades, there is nothing magical about any of that. You just need to be careful, use proper fusing and you need to know how to read the electrical code.I would say that rules out about 80-95% of DYI users.
jacquesm: This is 'hackernews', not 'consumersRus'. Though on odd days you might think differently.
jacquesm: > Wouldn't you mention it if someone was misusing a Dutch word?Not a chance. Language is a tool, not some kind of holy house. If the meaning comes across that's already more than you could hope for.The whole idea that language is something to be condensed and frozen is relatively new, it used to be much more fluid which made it harder to have a decisive set of words (sorry, Scrabblers (tm)) but language could adapt faster to circumstances. What we consider the 'final form' of all of these languages isn't final at all, it is just what we are used to and more of a convention than anything else.Some countries (including mine, unfortunately) have groups that will go out of their way to harass people to use the 'correct form' ignoring that what those forms are is subject to change and that not everybody grew up with the currently agreed upon preferential way to spell things, and meaning is so much more complicated than spelling.I think the easiest way to deal with these kind of frustrations is to see them as compliments: at least someone was aware enough of your language to name something in it, that's more than you could say for many other languages, if only because the scripts are different.
MisterTea: > This somewhat limits the usefulness of the hardware anywhere you need to be insured, e.g. your house, boat or van.Same goes for all the random Chinese inverters people are buying and installing in their Homes, Boats and Vans. Doesn't seem to stop them.
throawayonthe: those are usually certified?
mindslight: Insurance covers the insured's own gross negligence. This trope is up there with believing the "warranty void if removed" stickers.The real reason this should give you pause is that you don't want your house to burn down regardless of an insurance payout. That is how your incentives are aligned with the insurance company.
hamdingers: > Anything grid-connected, you REALLY want a licensed electrician to plan and install.Have you heard of balcony solar?It's a solar panel, a microinverter, and a standard wall plug. It doesn't need an electrician to install any more than anything else, you just plug it in. Outlets work both ways.LibreSolar doesn't seem to be working on any inverters, but a complete open source system like this would be great.https://en.wikipedia.org/wiki/Balcony_solar_power
bityard: If that wikipedia article is right, then balcony solar is not legal where I live (in the US). Here, we require a hard-wired, permanently installed automatic transfer switch that disconnects the solar generation from the grid when the mains power goes out. This is to protect line workers when working on downed lines.
mcbishop: Not that this is accepted by insurers or AHJs ("authorities having jurisdiction"), but one can use UL-certified components in an (open-source) _assembly_ that itself isn't UL certified. This at least supports the argument that the overall product is safe if thoughtfully designed and assembled. An example is the OpenEVSE level-2 car charger (which I had a really good experience with).
hamdingers: It's probably coming soon for you, 30 states have bills announced or introduced legalizing plug-in solar and one (Utah) has already passed. They should be fairly uncontroversial.Also, there's no need for a transfer switch in any grid-tied system, whether plug-in or hard-wired. Grid-tied inverters shut off automatically if there's no grid frequency to sync to.
goodpoint: > Libre does mean free as in freedom, but it also means available and released from prison.If anything it makes it more apt.
mcbishop: > Why the fearmongering?The main concern is exporting to a downed grid that line-workers are trying to restore.
jacquesm: If you can design and build your own inverter I would take it as read that you know how to read code and know how an actual inverter should function:If you're grid connected and see valid phase on the input for a certain amount of time of matching phase and measuring voltage you can provisionally connect at exactly that phase and voltage but without injecting power. After that you are allowed to slowly ramp up your output by leading the phase (while raising the voltage within certain limits) as long as you observe the effect that you have on the grid. If the grid phase drops away or there is any other anomaly (such as a voltage drop or rise of more than x V/s you are required to immediately disconnect, there are many other disconnect requirements but that's the main one with respect to line worker safety.Three disconnects within a short period of time = no reconnect attempts for a much longer time. If the situation persists that's a failure and you are no longer allowed to connect to the grid until there has been an intervention and an inverter reset.If your inverter is of the islanding variety then the rules are slightly different, then the transfer switch only gets energized when you match voltage and frequency but in the meantime the (usually battery backed up) inverter can supply local consumers.By the time you come up with the idea of rolling your own inverter you have either become familiar with the requirements (which differ from region to region, and which in a properly designed inverter are mostly a matter of tweaking firmware parameters) or you will have to do so because you realize your responsibilities.Anybody up for this kind of project will with a high degree of likelihood have the required knowledge because that knowledge is a lot simpler to acquire than the knowledge to build an inverter that isn't going to result in you being laughed out of the room when your EE buddies come look at your creation.I would expect you to do a better job than 95% of the imported ones that I've taken apart and which all had massive shortcuts taken, good enough to pass first inspection and a year into warranty, not good enough for long term safe deployment. This ranges from unsuitable connectors, low quality inductors, even lower quality relays, undersized FET boards, insufficient cooling, bad cast aluminum housings, in general bad housings (not rodent and/or insect proof) and so on.
jacquesm: That simply is a transfer switch that is built in.
jacquesm: 99.9% of all inverters currently being sold has this functionality built in. That 0.1% remaining you will find in the second hand market and the bargain bin of Amazon.
hamdingers: What would it be transferring the load to?There is nothing performing the role of a transfer switch in a grid tied micro inverter.
jacquesm: In grid tied inverters with batteries the transfer switch can be built in to the inverter or it can be an external switch. Similar to how you would use one with a generator setup.And indeed these are uncommon, mostly because they tend to be more serious devices. Victron and formerly Xantrex make nice ones.For the solar balcony and more common rooftop solar setups there is only a simple disconnect. The downside of that setup is that if there is no grid but you do have solar that you still have no power.
hamdingers: A disconnect and a transfer switch are not a same thing, "transfer switch" refers to a specific type of switch in a specific role as I have described. Conflating the two is incorrect and benefits nobody.
thedougd: The other one that drives me nuts is “sensitive electronics” in generator discussions.
mindslight: [delayed]
mcbishop: Thanks, and I agree that a DIY-inverter designer should be able to meet grid-interconnection requirements (e.g. IEEE 1547-2018). With that said, I think case-by-base evaluation from the AHJ would be prudent without a UL listing... something that AHJs don't want to do.I'd prefer to just put the DIY inverter behind a transfer switch (with an adequate battery bank and maybe a small propane generator)... with the grid as emergency fallback.
vanillax: Great use case for solar shed/offgrid/cabin... I think people underestimate how much you can do with a solar shed , batteries, and the sorta reduced risk aspect of a shed catching fire vs a house. That being said its really easy to follow safety precautions. I cant wait to try this out.
jillesvangurp: It's not like generators, furnaces, etc. aren't a fire and safety risk. Lots of people die every year because of carbon monoxide issues with generators, furnaces, etc. Not to mention gas leaks and related fires.Safety is important of course. But people are being very selectively paranoid about this stuff.Same with EV batteries vs. ICE engines. Combustion engines that intentionally explode highly flammable fuels sometimes catch fire (surprise). People think nothing of parking them in garages connected to their house. Sometimes those cars are quite old. Maybe the wiring is a bit dodgy. Or the fuel hose a bit dried out and leaky. And the guy you pay to fix your old car is maybe not a trained professional. Or something else goes wrong. In short, it's extremely common for vehicles to catch fire (most common reason for fire trucks to get called to a scene). And lots of people die in vehicle fire related incidents. Almost all of which are good old ICE cars. Yet all people talk about is battery fires in EVs. Which are quite rare and pretty much never happen at all for certain newer battery types (e.g. LFP, sodium ion).
rsync: We require transfer switches, but they do not have to be automatic transfer switches.In the United States, you are one small piece of sheet metal[1] away from any number of interesting power set ups on your side of the utility.This means a combination of two circuit breakers is now your transfer switch. This is legal with all utilities and NEC compliant, etc.If you are willing to sacrifice perfectly uninterrupted power, you can dramatically simplify your grid tie - and open up many other possibilities on your side of the physical interlock.[1] https://www.daierswitches.com/products/sd-200vl-generator-in...
DamonHD: That roughly lines up with what we paid* to get CE and safety stuff done for a small battery-powered product with a radio on the EU market (primarily in the UK).*Testing and tweaking and then sign-off in grown-up labs.
adrianN: I’m fine with people using „gratis“ to differentiate libre software from software that doesn’t cost anything and I’m German.
hexfish: They speak Latin there?
adrianN: Gratis is a German word.
danw1979: So in the UK you won’t get sign off from building control if your electrician uses a dodgy uncertified device, and that results in your insurance being invalidated, at least according to my policy.
stephen_g: The cheap stuff usually have the certification labels printed on them, but a cursory look inside usually shows breaches if you know what to look for (like we have had stuff from China where the ground wire wasn't connected to anything, but even if that's right there are things like just not having enough clearance between mains and isolated DC in power supplies etc.). So they are definitely not actually certified, they just slap the labels on anyway.Of course, there is a rising group of actually really high-quality native brands starting to come out of China - Anker were an early one of these, Xiaomi is a massive one, UGreen is really popular on Amazon etc. These kind of brands actually will be properly certified and are scary good for how cheap they are. So it's changing a lot.
seb1204: I thought Anker and UGreen are Amazon brands by now?
jacquesm: That's exactly the setup that I had in Canada with a windmill thrown in for good measure (which really helped in the winter, after we got the windmill up we never ran the generator again).
danw1979: this is a really good point that I neglected in my original dismissal of the project: it's going to be super useful for DIYers and small shops in the less regulated parts of the world.
ktm5j: IANAL but I don't think that's true at all. Electrical work needs to comply with code standards (NEC). I'll eat my hat if an insurance company pays for a fire that was caused by using homebrew electrical systems.
jacquesm: With a Latin root.
mindslight: I'd really like to see citations to the opposite. After all, the main function of most homeowners' insurance policies is to keep banks whole regardless what happens.I suppose there is a legal path of being criminally charged by fire investigators for having performed unsafe wiring (non-Listed power handling equipment as part of the fixed wiring), and then the insurance company denying you because of that criminality. Or perhaps declaring that the wiring itself is "illegal" (as it goes against the NEC (despite the NEC not being openly published as we generally expect from laws!)) and then hanging their hat on illegality regardless of criminality? But does any of this happen in practice?
1970-01-01: You don't think RF noise comes out of the generator?
thedougd: Sure. It’s just rarely what lay people associate with “sensitive”. Most customers are worried about small electronics with switching mode power supplies that wouldn’t have a problem with just about any power source.I wouldn’t run some AC motors, old AC clock, ham radio, or many other things on some generators.The line is open to interoperation and never defined by the manufacturer. It’s blanket liability avoidance that confuses customers.
mindslight: Do conventional synchronous generators not cause the problems they purportedly do? I've got an inverter generator simply for fuel usage.I've certainly had my fair share of square wave UPSs and devices that don't work on them.
thedougd: This could be because of a floating neutral.There are certainly cases where harmonic distortion is a problem for a device. It’s just that everyone is left guessing, and there’s an overblown fear of devices being harmed.
DamonHD: https://www.sciencedirect.com/science/article/pii/S2352152X2...Quantitative fire likelihood assessment of battery home storage systems in comparison to general house fires in Germany and other battery related fires
ktm5j: Like I said, I'm not a lawyer.. and I'm no longer a homeowner so I don't have an insurance policy. So I don't have a citation for you. I may be wrong about this, but I don't think that I am. If anyone who's in the know can help then I'd be okay with being proven wrong.
