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DIY Off-Grid Solar Power

mobile-solarpower.com

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Re: DIY Off-Grid Solar Power

#51

Post by zdragnar »

Syonyk wrote: post #39
jf wrote: post #15

Earlier quoted context omitted.

Could you dig a hole for your batteries and store them below the frost line?

The problem with holes in the ground for storage of things like batteries is that... they're holes in the ground. The ground, as a general guideline, actively dislikes holes in it and strives to fill them in whatever way possible. Liquid rolling in, soil creep, debris blowing past and building up, it doesn't matter - given a long enough time, a hole in the ground won't exist anymore. You can build a hole that will ho…

I think you are way overselling the difficulty of digging a hole in the ground. Go to any grave yard- full of sealed coffins, all below the frost line.

Get a plastic storage box, drill holes for cables and seal them with caulk. Put inside a treated lumber box for extra crushing resistance. Run cables through metal conduits to avoid mice and moles chewing on them.

Rent a backhoe, and you are done in half an afternoon.

All of that said, I dont know that I would actually go that far- you avoid the battery freezing, but then you get to worry about it cooking. For an off-grid cabin that isn't constantly heated in winter, it isn't the worst idea.

Re: DIY Off-Grid Solar Power

#53

Post by nataz »

Syonyk wrote: post #7
ctime wrote: post #2

Will Prose seems like a really great person. If you’re interested in what you see on this site, check out his YouTube channel: https://youtube.com/c/WillProwse

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…

"It's especially wrong when you try to make it about personality, humor, etc moreso than hard technical truths."

Have you spent any time watching Will's videos? Your quote doesn't match up at all with what I've seen at all. I found his videos dry, technical, and pretty good with regard to safety.

Re: DIY Off-Grid Solar Power

#54

Post by barbecue_sauce »

Syonyk wrote: post #30
kyleee wrote: post #19

Earlier quoted context omitted.

"YouTube is simply the wrong medium to try to teach detailed" YouTube is literally just humans talking, so you are basically saying you don't think humans can teach complicated subjects?

That's an absolutely absurd characterization of both YouTube and actual teaching. YouTube is dominantly entertainment/personality based "edutainment" at best, based on what seems to percolate to the top and be promoted. There's zero feedback outside comments (standard warnings about comment sections apply here). The right way to teach complex subjects is a more interactive process with hands on material/learning/actu…

A lot of educational content on YouTube is made by people who have no idea (or interest in) how to optimize for engagement. I'd be willing to bet there is fairly competent basic EE instruction on YouTube that includes lab instructions, working with simulations, problems, and pulling in other exogenous resources to aid in understanding. Its not just a wasteland of pop science like Veritasium, et al.

Re: DIY Off-Grid Solar Power

#55

Post by mcot2 »

Syonyk wrote: post #44
jandrese wrote: post #36

Earlier quoted context omitted.

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…

Adding on to this the energy usage of my multi-head heat pump system has been quite surprising when it drops below freezing. I have a Mitsubishi unit which is rated down to something like -15F however below 32F it uses enough energy to get pretty close with fossil fuels on price. It looks like I will have to add on to my 11.85kW solar system to be able to get the projected energy use throughout the year. Winter time will have a significant deficit and summer overproduction will make some of it back but not all. I am also investing in air sealing and additional insulation.

Re: DIY Off-Grid Solar Power

#56

Post by barbecue_sauce »

woleium wrote: post #31
kyleee wrote: post #19

Earlier quoted context omitted.

"YouTube is simply the wrong medium to try to teach detailed" YouTube is literally just humans talking, so you are basically saying you don't think humans can teach complicated subjects?

YouTube encourages generating content that rates well, i.e. is entertaining. I agree that learning should be fun, but I don't want to learn about life threating topics from videos that are designed foremost to be entertaining.

There is plenty of non-entertaining yet informative and detailed educational content on YouTube. The "entertaining" videos are usually just a gateway to more dry and traditional lectures and courses that are provided by universities and other content generators that see YouTube as a general resource and not an income stream.

Re: DIY Off-Grid Solar Power

#57

Post by belval »

Syonyk wrote: post #47
post_break wrote: post #33

Earlier quoted context omitted.

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 chemistr…

I was giving you the benefit of doubt, but this comment shows that you've never watched any of Will's video and you are just painting with a very broad brush.

He's the kind of Youtuber that keeps repeating that you should place a low temp sensor on your cells, not the kind doing sketchy spot weld on old 18650s.

Re: DIY Off-Grid Solar Power

#60

Post by recursinging »

For folks interested in a more basic, low level, open source approach to this topic, check out Electrodacus [1]. I built a small system using the SBMS0 in my camper van and have been pretty pleased with the results. If having access to schematics and source code is important to you, have a look.

[1] https://electrodacus.com/

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