I found a deal on 4000 watts of solar panels for $400 but they are high voltage like 200 volts per panel. Am I correct to assume these are not suitable for DIY off grid projects?
Why would you assume this?
>>2977191All the cheap charge controllers max out around 50 volts. As near as I can figure I would save money on the panels but then have to buy a $600 charge controller.
>>2977193Yeah, the voltage is a problem. Even 48v inverters have an 800v max on the mppts. You can't string very many of these together. Like, I'd do 3, and at max current of 2.3-ish amps, you're not getting much out of these panels. The burden of finding equipment to make use of these things is a lot. If you haven't bought them, walk away. If you have, find a bigger sucker.
>>2977203>If you haven't bought them, walk away.I didn't. What do you think about these 580 watt panels. The voltage is lower. Would it be reasonable to put 4 in parallel?
Dam up a nearby valley and use the output of the panels to pump water into your new reservoir. Pumps are simple things and will happily use 200 volts. You can then use off the shelf hydro equipment to get electricity out of the reservoir's gravity potential.
>>2977188High low amp can use smaller wire tho from the panels to the controller Probably a good deal for the right set-up
You can easily just parallel them into a 3-5sXp at 800-1000V strings with a 1500V rated inverter, it's not rocket science. This really isn't much different than regular solar panels, maybe cabling will be slightly more messy. If there's nothing wrong with the panels then it's perfectly fine to buy these. Older inverters have issues with the high voltage, but all modern inverters are at the very least 400V-ish.https://rentry.co/solarshit
>>2977209These are similar to panels I bought for myself. 40-50 VOC lets you string 10 together and occupy one MPPT. Do this twice and you have enough energy to feed a single family home at 49 degree latitudes in the winter. As long as you're using heat pumps for heat and hot water, anyway.
Then convert volts into amps :>
>>2977303>10kWpThat produces a good 1kWh per day on a cloudy winter day, you better be well insulated.
>>2977322Limiting air leakage first. Casement and awning windows, plus Henry VPTech exterior insulation. The insulation matters, but controlling air leakage matters more.This is 2 strings of 10 each 350w panels for 7kw nominal btw. I'll still have 12 panels left over.
>>2977337> why did you suffocate to death anon?I eliminated all sources of “air leakage”
>>2977358HRV. Delivers fresh air to the building without wasting heat energy from stale conditioned air. Required by code and by sane HVAC specifications for tight envelopes in states with 21st century building standards. I forgot you might live in a shithole state so the inclusion of an HRV or ERV may not be implicit.
>>2977193>All the cheap charge controllerswell then don't get the cheap ones. simple as.
What do those boxes do anyways?A step down transformer isnt hard to make and if its dc it can be converted to ac. Lastly if you need to store the energy theres car batteries. What am i missing?
>>2977378Everything, you're an idiot, give up and apply for autismbux.
>>2977362>Heh, I've spent $15k with $200 average yearly upkeep to save $500 per year on the utility bill, am I a genius or what
>>2977193True if simple 12 or 24V off grid system. Hybrid inverter chargers can handle (and also use) the extra voltage. They are 10 times as expensive but then delicious AC. Vevor has a cheap one.
>>2977448Well if the op wants to cheap out on spending $600 on a box i think there is a way to diy it and it could end up being cheaper if hes willing to put in the time. There are some things that are not practical to diy sure. Like soldering ram or making a fancy radio duplex transmitter or more complex circuits but this does not strike me as one of those things. Idk theres metal transformers from microwaves that have good iron cores though those are a bit scary and need to be discharged.>or you get socked to death
>>2977545>socked to death
>>2977378Depends on the "box"Cheap pwm charge controllers do what it says on the box. Run pwm to reduce panel voltage down to whatever voltage is needed for charging the battery. They may have some simple charge logic or may just a be a dumb "Here's 13.6v, enjoy". They are terribly inefficient and don't work if panel voltage drops below what you want out.Mppt use either a buck converter, or buck boost converter and a bunch of microelectronics to shift around voltage and current input vs output to match the panel as it's power output changes due to clouds, time of day, shade, etc. An inverter was also mentioned, in which case the, typically mppt, charge controller also has a DC to AC inverter tacked on, giving out whatever your country's flavor of power.Mind you, for any real power we are talking 150+ volt systems, can easily be 400, 800, or even 1000 volts. Not very diy friendly. On the other end, a small 24v or 48v system with a couple 100 watt panels can prolly make a diy controller feasible, but once again, a low voltage system of any real power will be passing around 100+amps. Not diy friendly.So no, unless all you want is a small pwm system to run a couple lights, you are not realistically going to diy anything to do with the "boxes"
>>2977193>Cell Type CdTeThat is unusual, and it is also hazardous waste. Cadmium is hazardous.
>>2977449A simple fan with a temperature differential controller in the attic and garage would do the same thing.
Wide input range DC-DC converter might work.
>>2977188Lotta 250-450 volt mppt chargers out there anon. Look at their amp limits and the panels wiring gauge.
>>2977188I have an idea and yeah it's probably stupid, since I don't know WTF I'm talking about, but if you are in a mostly cold climate, for that kind of deal I'd grab these and use them STRICTLY for heating. Wire them straight into some giant, cheap electrical baseboard heaters and just let'em run continuously. They'd handle the voltage with no problem and it's a purely resistive load.
>>2978926It's pretty stupid, but you're not getting the worst post in the thread-award.
Just ordered some pecron shit, getting into solar for the first time. Whats the current meta on 400w ish portable panels? I ordered a few to test out and fuck around with but will probably get to like 3kw worth eventually, wait for black friday and order 4-5 good N type is kind of my current plan
I dont know shit about solar but how is it someone has 4 kilowatts worth of solar cells with no way to use them? Don't they make controllers or BMS type systems to use them? How do the manufacturers suggest you use them?
>>2979109>like 3kw worth eventuallyWhy are you aiming for 3kw of flexible panels anon? Do you have any use at all for a fixed installation of panels?The flexible/portable ones arent as reliable and dont last as long as the glass ones anon.
>>2979109Why portable? 3kW would be huge size, unless you're putting them on a boat or a curved RV, there's no advantage to them, and even on a boat you should just use regular panels.>>2979141Like multiple people pointed out above you, these panels are fully compatible with regular PV hardware.
>>2979141Those panels are from FirstSolar, they focus exclusively on making panels for the commercial power market. Think acres of solar panels. That industry has moved onto 1500v as the basic input, where residential panels generally tend to be around 800v inputs, and geared towards silicone based solar cells outputting ~50 volts.
>>2977188That's probably the VOC, under load it drops to 50v.
>solar general isn't upYou guys in this thread are probably knowledgeable on this. I have some relatives who want to install solar, this is in Europe. I'm more of a /g/fag than a /diy/fag so I don't think making our own system is feasible, and I also don't want to be on the hook for helping them support a diy-ed setup; are there any /diy/ approved brands for solar batteries/controllers/systems?They're unironically considering a tesla powerwall, and I'm thinking surely there must be things that are cheaper and better and less pozzed, without going the route of buying our own inverters and batteries and all that shit and wiring them up all on our own.
>>2981312https://rentry.co/solarshit>are there any /diy/ approved brands for solar batteries/controllers/systems?>without going the route of buying our own inverters and batteries What exactly are you looking for here? If you want a good semi-budget-friendly brand to search installers for, then it's Deye (or one of the million names they get rebranded to, like V-Tac, Sunsync and whatnot). Just keep in mind that the inverter is LOUD when it's under significant load, it shouldn't be placed too near to living areas if you can help it.
>>2980443Voltage doesn't drop by more than 25% from open-circuit to maximum-power, from my experience with halfway modern monocrystalline silicon solar like that picture looks like. Even then, it's a pretty good idea to spec your charge controller to handle that maximum open-circuit voltage of the panels.
>>2981338loud as in 50hz hum or 10khz pwm screaming
>>2981455Neither, loud fans screaming WHOOOOSH.
>>2981451Guess so if you slam the disconnect close at high noon your inverter might have something to say but parallel setups are so skechy on the other hand that I'd rather lay my trust in the input varistors.
>>2979182Because I was a retard, i figured out that the portable ones are basically a ripoff and got a great deal on a full pallet of panels. Gonna have some in case of ww3 for use with the pecron and am going to do a full solar install in the future
ground containment cleaning using electrokinetic remediation. concentrate chems around anode cathode makes removal easier, fix dead land by removing nasty pollutants in soil set forget come back in a few years remove dirt plant sunflowers/bioaccumulators
People are selling 285W used solar panels in my area for £25 each.Judging by how they look, they are at least 5 years old, maybe a bit more.I don't have anything else (controller, batteries) but I plan to install 24V DC lighting (with battery backup) in the house I'm buying, and a few solar panels might help. Also security cameras and permanent decoration lights, all DC.My main goal would be "having lights and phone charging work in case of grid failure", and that is worth up to £1000 investment to me. I don't care about inverters or any kind of connection to the grid (for the DC circuits).Q1: Are used panels worth that much, or am I paying for someone's garbage instead of them paying me for disposal?Q2: Am missing something obvious with my plan to have lighting + other crap on a dedicated 24V DC circuit?
>>2982586No clue about the quality of those panels. If they haven't been physically damaged then 5 years should be well within their operating lifespan, but who knows if that brand or model is prone to delamination or UV damage or corrosion or whatever.As for your plan, even without the inverter you'll likely need substantial DC-to-DC converters. Lighting and USB chargers may be fine running on varying battery voltages (e.g. 20-29V), especially if it's designed for 12/24V automotive use, but chances are you can't find an NVR that can do the same. The standby power shouldn't be anywhere near that of an inverter if you pick the right one, but it's definitely something to factor into sizing your battery.
>>2977188200-400 volts is pretty normal for a residential panel. you then use a transformer to get 120v or whatever.
>>2982590>direct current>transformer
>>2982586At its lowest, I've seen 400-450W panels go for 50 euros brand new, so that's not much of a deal. Question is if {current year} happenings will enable prices like that still. So for Q1, so-so, leaning more towards garbage disposal. Q2, well, cameras with PoE tend to be on 48V at best, lights are all over the place. If you're talking about a small house/tinyhome then this plan is fine, but if you are talking a regular full-sized house, you're better off with the flexibility of having AC mains everywhere I think.You could have a small cheapo ~3kW hybrid solar inverter that gives UPS power to only select circuits (i.e. lights, a few sockets). With this, you can always add regular fridges or any kind of normal AC mains appliance to the stuff you want to back up. This can theoretically fit in the 1k budget still, although if you wanted a fancier (name brand) inverter, then it would jump up to at least twice that.
>>2982632>400-450W panels go for 50 euros brand newI'm seeing these prices on Facebook Marketplace, but I can't for the life of me find a reputable seller online (in bongland). Where do people buy cheap panels with warranty?>AC mains everywhereAll outlets will stay 230V from the grid, no connection to solar or batteries.>inverter that gives UPS power to only [...] a few socketsGood idea, but unfortunately I can't legally /diy/ 230V circuits, only up to 50V is permitted, hence my focus on lighting/cameras/USB-PD charging.
>>2982587>DC-to-DC convertersThat's because the battery voltage fluctuates between full and empty, right?>Lighting and USB chargers may be fineYes, pricier lightbulbs are rated for 12-48V, and the USB-PD stuff I got works with 8-30V. My router accepts 12-24V and the cameras probably will be either 12 or 24V, so I'll definitely need these two to be powered through a converter.Thank you for the tip, I completely disregarded this part.
>>2982643>That's because the battery voltage fluctuates between full and empty, right?Yeah. Some things can handle it anyway, what matters foremost is the maximum voltage tolerance and minimum dropout of the internal components, though even within those you might be outside the intended operating regime of things like switching converters, and linear regulators may get too hot. Still, I bet my computer could run directly off a 10-14.6V battery with step-down converters to 5V and 3.3V rails, 15V is a common maximum voltage for components to operate at. Not that I'd risk it with my nice computer.People run 12V LED strips off car batteries all the time, but I'm pretty sure they'll be overdriving those LEDs at 14V from the alternator enough to lower their lifespan. They normally drop 3V or so across each resistor, at 14V that would increase to 5V, pushing almost double the current through each LED.>USB-PD stuffCan't you just feed a PD device 28V without it frying? I know I've heard of some people wiring 12V from their car directly into a USB C to charge their phone, but I don't know enough about the standard's implementation to say that any PD device that can operate at 28V will survive being fed that without negotiation. Well probably best to use the little automotive-style hard-wired PD supplies anyhow, they should be pretty efficient.Man, we really need an arbitrary voltage negotiation standard in the 5-50V 0-50A range that doesn't require a DC-to-DC converter at both fucking ends. Can't we just have a machine that will accept anything from 8-30V, negotiate with a battery and confirm that it won't blow up, before turning on its output?
>>2982644>12V LED strips off car batteriesIt only works for very short strips, because at 12V the brightness drop is very noticeable towards the end of the strip. Otherwise they need to inject power at the middle and the end of the strip.At 24V it's much better, injection isn't mandatory.>Can't you just feed a PD device 28V without it frying?No, USB defaults to 5V 2.4A (maximum) without negotiation. The negotiation can be performed by a PD trigger, they are very cheap and small and can be attached to any device.There are even cables with these embedded.
>>2982644>Can't we just have a machine that will accept anything from 8-30V, negotiate with a battery and confirm that it won't blow up, before turning on its output?We have autosensing battery chargers.In the other direction, you're literally describing USB-PD. I'm stocking up on modules with the aim of adding at least one to each room, installed permanently in the wall. 60W is enough to charge any laptop that has PD charging, and ultrabooks will even work happily with that much power. Any tablet or phone will charge quickly, and for random devices there's cables like the one above.
>>2982641>oi, do you have a loicence for that circuit>Where do people buy cheap panels with warrantyThe warranty on panels is provided by the manufacturer in the event of a failure, but solar panels are extremely dumb technology, they don't carry a huge risk of any particular failure. Just make sure it's a T1 manufacturer, that's it.
>>2982670What about degradation warranty (e.g. that they'll provide 80% of their rated power in 20 years or whatever)? I heard some manufacturers have that. Is that worth anything at all?
>>2982671The degradation warranty is the most useless, because if it's fulfilled by the manufacturer, they can easily fuck you over by requiring you to ship the panel to god knows where and that'll be far more expensive than buying a new panel. The comprehensive warranty can be provided directly by the official distributors and can have much better terms. These are just generalizations though, it can be one way or another. My recommendation is that if you can get 400W decent-looking panels for $50 and they have good reviews then just grab that, maybe buy 1 spare. It's not worth gambling with big arrays, but on a mini 3kW system on a garage roof, you can just swap the panel in minutes if anything were to go wrong. Also you don't need to EXACTLY match the panels in the event of a replacement, just mainly have to try to get the same current.
>>2982647>No, USB defaults to 5V 2.4A (maximum) without negotiation. The negotiation can be performed by a PD trigger, they are very cheap and small and can be attached to any deviceJust because a PD load is requesting 5V 2.4A by default doesn't mean you can't wire it directly up to a dumb 12V source instead of a PD negotiating source.>PD triggerPD triggers are handy for sure, if you have a non-PD load and a PD source. But I'm talking about the opposite situation where you have a PD load and don't want to bother with the additional DC-to-DC converter inside a PD source, burning quiescent power and being another thing to go wrong. But as I said, it's sketchy.>>2982652>autosensing battery chargersNot smart enough to be as universal as I'd want. Ideally you'd have a protocol that can power CC and CV loads when the source is compatible. You'd have various load and source types, say a variable CC/CV source could power a CC LED load but a battery could not, but that battery could power a dumb heater. Plug in the 50A load, supply says it can only provide 20A, so load only draws 20A, that sort of thing. Probably also run multiple loads in parallel where they check to make sure the total current adds up to below the maximum, maybe even multiple sources in series.>In the other direction, you're literally describing USB-PDA high bit-rate miniature compact connector being used for power delivery? It's convenient if you want 5A or less and don't mind a DC-to-DC converter at one if not both ends of the transaction, but in many cases you can get away with one or even no DC-to-DC converters. For idiot-proof off-grid connection.
>>2982713Having researched this stuff a bit today, I must say that I'm disappointed with the state of DC interoperability, in both directions.There's not even a standard for DC wall sockets, or any kind of power source sockets, really. USB-C female is the only DC connector you can confidently put in a wall.And it's all so wasteful... I tested the PD module from my previous post, and it heats up to 98°C while charging my phone through it.
>>2978567the best performing materials often tend to be not very human-friendly. The most efficient solar panels to this day are made with lead perovskites
>>2978926>>2978930Or, hear me out, OP can plug them into a resistor, use it to boil water and spin a turbine
>>2982744>USB-C female is the only DC connector you can confidently put in a wallDon't be forgetting PoE!
>>2982762That too, albeit not as sexy.
>>2982744
>>2982828If we're talking DC connectors that don't negotiate power, then XT60s and similar can also be panel-mounted, same for hybrid dsub connectors like the 2W2. Though I think those 50A andersons are on top of the caravan game. Maybe followed by the smaller power-pole connectors. They're nice and genderless, which is usually pretty useful but it does mean you can unwittingly plug two batteries in parallel if you get your connectors muddled. Not that that's the end of the world, depending on the amp-hours of imbalance. There are other colours of anderson connector that have keyings, though I think I'd only expect to see them being used to make important seperations, like before/after a charge controller, or different voltage levels.
>>2982838Thanks for the info, but the discussion is mostly around the last connection in the chain: consumer device to wall socket.Something like pic related, but with some sort of protection against incorrect voltage and against accidentally shorting the female jack by sticking some metal object in it.The female jack would be mounted on a wall plate in this scenario.
>>2982869XT60s and Anderson Power-Pole connectors are used somewhat widely on consumer power-stations. So is a laptop-like DC jack. All of these have options for a third pin through which some form of validation could be done, if I recall the XT60 extra pin is used by some power stations such that they don't draw more than 10A from a cigarette socket but can draw more from solar panels. That said, I doubt that's done on the DC jack ones since they're usually lower-power 10A max inputs anyhow, and the power-pole data pins make the connector physically wider and incompatible with other connectors. But power stations are pretty resiliant against various voltage levels at their input, because they take solar panels as direct inputs.Conventional Andersons also lack any means for communication.Normal 5525 or whatever barrel jacks are something I'd prefer to only see going one way, i.e. male = source, female = load, if just for removing ambiguity. Not that you run into any issues when the females are basically always on wall plugs, just the occasional guy with the wrong cable like with PAL TV antenna cables. Now that you mention it, it's strange that we do it this way around considering the female is easier to short than the male, it's the opposite of an IEC connector.There are some IEC-like connectors used for DC, like the ones found on portable fridge-freezers, though like a barrel jack I've never seen one on a wall-plate. There's also a larger US/AU-style wall plug where the two flat blade connections form a T shape that I've heard of being used in caravan wall-plates. Rated to 32VDC 15A. Cig plugs are pretty bad for retention and standardisation, but the similar but smaller and higher-power Merrit plug is found on some european and australian road vehicles and boats. BMW motorcycles come to mind.
>>2982870>5525>male = source, female = loadIndeed, that seems to be the universal approach. The big problem is how to feed power into the male connector. It can't just be a permanent cable that dangles from the wall.With USB we solved this, but it requires active components and DC-DC conversion in place. There seems to be no easy solution for an already conditioned 12/24/48V power feed at the wall side.
>>2982873>The big problem is how to feed power into the male connector. It can't just be a permanent cable that dangles from the wall.I've definitely seen cases where male-to-male cables are used, and even some appliances where the load has the cable and the source has the panel socket, so it's not unheard of. But DC barrel jacks' biggest downside is universality without standardisation. Different voltages, different polarities, different current requirements and capabilities. Sometimes it's not even a constant voltage output but a battery charging output like for those lead-acid kids' ride-on cars or lithium ion flashlights. Where I work we sell 20-30 different DC adapters, each coming with 8 different plugs, covering a variety of different currents and voltages, some adjustable but most not. Is it fine to sell a 19.5V adapter for a 19V laptop? It's all so tiresome.At the very least, you could have a consumer DC standard whereby plugging in two random devices would have a dirt-cheap communication chip on either end to ensure nothing is going to explode before a MOSFET in the source kicks in to allow power to flow. No need for emarker chips inside cables, you can measure voltage at either end of the cable if you're paranoid. With a robust connector, not a tiny thing like USB C. All of the extra features I described would be a nicety for sure though: >>2982713. I actually bought a bag full of 7W2 plugs and sockets, planning on creating my own standard, at least for personal use but also to attempt to get others to adapt and improve it, where they'd talk CAN bus and negotiate to ensure the load and source are compatible without being overly restrictive. But the physical design wasn't really compatible with series sources, so I started looking at those strange power-pole hybrid connectors, but they flip their pins in a way normal power-pole connectors don't (also they're abandonware), so I'm kinda lost. Also I can't code for shit and have never done CAN bus before.
>>2982870>XT60Honestly, this looks somewhat sane. The disadvantage compared to barrel jacks is that it can't rotate freely, but that's a sacrifice I'm willing to make.Thank you for the suggestions, I'll keep both connectors in mind.
>>2982883They're nominally 60A rated, but the thickest wires you can fit in them is 12awg so you wouldn't want more than 30A continuous. XT90s are probably more sensible. Actually I think that power distribution board photo is of XT90s. They're less common in power-stations and remote control use though, so it's a trade-off. But yeah it's nice that both male and female can be panel or cable mounted.
