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DIY Off-Grid Solar Power

mobile-solarpower.com

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Re: DIY Off-Grid Solar Power

#41

Post by kortilla »

pengaru wrote: post #6
Syonyk wrote: post #5

Earlier quoted context omitted.

If you're going to do solar on an RV, you really should read Handy Bob Solar too [0]. The site formatting sucks, it's very much wall-o-text, and he's absolutely right in everything he says and rants about regarding RV solar. Far too many solar installers just treat a system as the entry to people coming back for more, when the problem is that they don't know enough to adjust it properly for the stuff that was install…

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Re: DIY Off-Grid Solar Power

#42

Post by kortilla »

pengaru wrote: post #14
Syonyk wrote: post #11

Earlier quoted context omitted.

I've been dealing with an off grid solar office for 5+ years now. Year round power, heating (propane at times, candles/kerosene at others, electricity most of the time if I have the light), and have spent the bulk of this time in some esoteric backwaters communities on IRC with other people who do the same sort of thing. It's really, really hard to find people who have written accurately about solar on the internet.…

How intelligent can the guy be when he's flagrantly demonstrating such flawed thinking? It calls into question everything he writes, full stop. Better things to do with my time and why give him more audience.

There are many intelligent people who purport to be Christian/Muslim/etc, which all require severely flawed thinking to seriously believe.

What you’re doing is conducting an ad hominem attack, assuming that this dude’s views on one topic have any relevance to the accuracy of a completely different topic (with a nearly decade gap nonetheless).

Re: DIY Off-Grid Solar Power

#43

Post by kortilla »

pengaru wrote: post #24
csours wrote: post #20

Earlier quoted context omitted.

Intelligence has almost nothing to do with it. The whole 'rona thing has been very very stressful and many people have not reacted well to it. Scam artists have exploited this stress (as they always have and always will). Some people have been led astray and some are leading people astray, and some are both. At any rate, it is an impairment of gathering and processing information correctly, not intelligence. It's a f…

Quoted post unavailable.

People who disregard everything someone has to say based on one belief are generally pretty stupid themselves. What an impressive way to discourage critical thinking.

Re: DIY Off-Grid Solar Power

#44

Post by Syonyk »

jandrese wrote: post #36
zoba wrote: post #8

I recently set up my own off grid solar system in a tiny cabin that I designed and had built. I used the Solar Controller+Inverter Combos recommended on this site (Growatt) but ultimately switched to ones by Renogy. The Growatt one I purchased has a wifi adapter and app - wifi requirement was a deal breaker when remote. The renogy one has a Bluetooth adapter and app, plus feels better designed (though actually I thin…

Could you insulate the batteries to reduce the heating demand? Instead of heating the entire cabin just heat the battery compartment, and only to the minimum necessary to keep them from being damaged (plus a margin for safety). Maybe even just toss them in an old discarded deep freeze? You could even have one battery in there that is disconnected from the rest of the system so it can be used to jump start the system…

You can insulate them to reduce heating demand, and it will help to an extent (undo that before summer to avoid cooking them), but for an unattended system, it's never going to work out very well. If the system is a year round cabin, the solution is easy enough - keep them in the heated space (which you'll have propane/kerosene/biomass heaters for), and it's not a real problem. But unattended stuff... you really just need to plan for something that can tolerate bitter cold without damage. Or to seriously overpanel the system, 10x+ what you need for summer use, and hope they produce something.

I think most people underestimate just how much delta in production there can be on solar. My house array is grid tied, 16kW, a bit weird looking (mostly east-west panels, designed for post net metering). On a really good, cool, clear, windy spring day, I can produce about 105kWh out of the system from sunup to sundown.

On a really bad, low, grey, winter day, that same system produces about 2kWh. It's literally a factor of 50 difference. And we can get several days of that in a row. I have a backup generator that I use for my office on weeks like that (separate, off-grid system).

"Winter, electric heat on solar" is a fairly good filter for those who have read about solar or pondered it, and those who have a few years of it under their belt. The second group are the ones who've tried it, discovered just how horribly it doesn't work, and are trying to convince the first group that, no, really, insert well worn idea here really doesn't fix the problems with it.

I guarantee if it were easy, people would be doing it. That you won't find any serious off grid system doing electric battery heating is because it doesn't work.

Re: DIY Off-Grid Solar Power

#45

Post by stephen_g »

zoba wrote: post #8

I recently set up my own off grid solar system in a tiny cabin that I designed and had built. I used the Solar Controller+Inverter Combos recommended on this site (Growatt) but ultimately switched to ones by Renogy. The Growatt one I purchased has a wifi adapter and app - wifi requirement was a deal breaker when remote. The renogy one has a Bluetooth adapter and app, plus feels better designed (though actually I thin…

Yeah, some people had problems with all-in-one battery systems in their homes that were AC coupled to their solar here in Australia over some weather disasters where there were prolonged outages for that reason.

I’d quite like a battery system, I think I’d DIY (well, design the system but here you need a licensed electrician to wire up the AC/grid connect side) using Victron equipment. I have a 5 kW solar system already with a AC inverter which I can keep, so I would probably use a 5000KVA inverter-charger (Multiplus-II), but then I’d add another 1.5kW or so of solar that is directly DC coupled to the batteries and the DC side of the inverter-charger through a separate DC MPPT tracker.

So the DC coupled solar would be enough to kick-start the system to get the AC side back on after a bit if the grid was out and the batteries were depleted overnight.

Re: DIY Off-Grid Solar Power

#46

Post by thot_experiment »

NGL I think I have a pretty efficient setup and I'm in the process of installing a 4th panel (bringing my total to 1220W) because 915W isn't really cutting it for winter power now that I'm not spending time outside much. My quiescent draw/day is about 500Wh just doing nothing (fridge + internet) and on a cloudy day I'll make maybe 800Wh with the current setup. I don't think 800W of panels will let you power anything you want during winter.

I'm also working on a way to bring power in from my alternator but unfortunately I think I'm going to have to invert in the engine bay and rectify feeding into my MPPT controller to avoid running some absurdly thicc wire to carry a few hundred watts at 12 volts.

Re: DIY Off-Grid Solar Power

#47

Post by Syonyk »

post_break wrote: post #33
Syonyk wrote: post #7

Earlier quoted context omitted.

The problem with him, and people like him on YouTube, is that about 90% of what they say is fine, and 10% ranges from "iffy" to "This is a good way to burn your house down - at some unknown point in the future." The average viewer of that sort of material can't tell the difference, and by the time you can, you're not in need of handwaving entry level information, because you can read the design documents, spec sheets…

This is the dumbest take I've read in a long time. From him I've learned which lifepo4 batteries won't burn my house down, proper wiring for stuff, etc. I've got a 144ah battery pack sitting right next to me as I type this I built from learning from him. Are you sure your comment isn't about the youtuber Electricboom?

I rebuilt large (500Wh) lithium ebike batteries professionally and shipped them around North America for a couple years, and have torn down more than my fair share of ebike and tool batteries for analysis.

I've yet to see a "YouTube Trained" pack build that I would be remotely comfortable leaving unattended in my house. Though LFP is an awful lot more forgiving than a mix of random recycled 18650s of unknown chemistry, service life, and internal damage history that makes up the bulk of that stuff.

If you've got some good high res shots of the build process, I'd happily take a look and see what I think of it. My standards of comparison are the professionally built packs I've torn down for analysis and often enough rebuilt for people.

As for who my comment is about, honestly, I apply it generally to that entire class of person on YouTube no matter who they are. I know solar, and off grid solar, fairly well (with a focus on flooded lead acid). I know lithium fairly well, having done quite extensive work on them. In areas I know well, most of the people showing stuff off or trying to teach other people hit the 90/10 split, and as this is a topic of conversation in the quiet off grid backwaters circles I frequent, other people usually agree about which 10% is the problem.

Therefore I'm happy to ignore that entire class of person and go do something useful. It's not that education can't be funny, it's that when "personality" and "laughs" and "BIG O FACE I NEARLY BLEW MYSELF UP" style thumbnails are what matters, the really deep (and often quite important) technical details get lost in all that.

Re: DIY Off-Grid Solar Power

#48

Post by m0ngr31 »

kortilla wrote: post #40
m0ngr31 wrote: post #34

I live in an off-grid house. Solar isn't perfect, but it's been pretty good all things considered 6 months in. Converting an airport shuttle bus into an RV now, so I'll have to look this over for that.

Where did you buy the bus from?

Just from some local classifieds.

Re: DIY Off-Grid Solar Power

#49

Post by anamax »

pengaru wrote: post #14
Syonyk wrote: post #11

Earlier quoted context omitted.

I've been dealing with an off grid solar office for 5+ years now. Year round power, heating (propane at times, candles/kerosene at others, electricity most of the time if I have the light), and have spent the bulk of this time in some esoteric backwaters communities on IRC with other people who do the same sort of thing. It's really, really hard to find people who have written accurately about solar on the internet.…

How intelligent can the guy be when he's flagrantly demonstrating such flawed thinking? It calls into question everything he writes, full stop. Better things to do with my time and why give him more audience.

I take it you discount everything associated with Isaac Newton as well.

Re: DIY Off-Grid Solar Power

#50

Post by chrissnell »

mym1990 wrote: post #3

This is super awesome! I do some overlanding/longer roadtrips in backcountry but have yet to gather the courage to install a solar system. Certainly bookmarking this for future reference :D

I've driven something like 60,000 off-road miles since I bought my first truck in 2005. For overlanding, all you really need is a one big, high quality battery. The Odyssey PC2150 series are great batteries. Not cheap, but fantastic. It's very difficult to kill one.

Also, you'd be surprised how little energy you actually use out there. A quality fridge-freezer like an Engel or ARB can be run for days before it will discharge the battery in a parked truck enough to not turn the starter. This scenario pretty much never happens, so get a good battery, a good fridge, and you'll be fine.

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