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DIY Off-Grid Solar Power

mobile-solarpower.com

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Re: DIY Off-Grid Solar Power

#61

Post by throwawaysea »

chrissnell wrote: post #50
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 d…

Out of curiosity how far off grid do you go in your truck. That is, how far by distance and time are you away from the grid and stores? I know little about this stuff but am interested and would appreciate any helpful resources or videos you know of for a newbie. I’m interested from an overlanding / camping perspective but also a bug out vehicle perspective.

Re: DIY Off-Grid Solar Power

#62

Post by madaxe_again »

Syonyk wrote: post #28
poleguy wrote: post #22

Earlier quoted context omitted.

Have you considered Lithium Titanate batteries? They can discharge at a temperature of -40C.

Have you priced LTO? They're rather staggeringly expensive for their capacity. The cycle life is excellent, but they excel in very high C-rate applications (10C-20C), which is the opposite of what you need for off-grid systems. If an off grid system is getting anywhere near C/10 discharge rates, you're going to be in the dark awfully soon. It's old tech, it's boring, but it works fine... flooded lead acid. Don't full…

Yeah, lead wins hands down. This is a few years out of date now, but when speccing out my system I did a bit of analysis of battery types. We went with OPzS, and so far, so good.

https://docs.google.com/spreadsheets/d/1w8vPBHkMyY5jvkxtK1Qh...

Re: DIY Off-Grid Solar Power

#63

Post by [deleted] »

barbecue_sauce wrote: post #54
Syonyk wrote: post #30

Earlier quoted context omitted.

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.

[deleted]

Re: DIY Off-Grid Solar Power

#64

Post by t0mas88 »

thot_experiment wrote: post #46

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 could get a 12v to 48v DC converter on the car side of things. That already helps a lot in cable thickness.

Re: DIY Off-Grid Solar Power

#65

Post by Dylan16807 »

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.

> Either way it's a non-negotiable indicator for a high probability of noise in the signal emitting from his general direction.

Well yeah, the noise is the most recent posts.

Easy to filter out, too.

And what, do you not think someone can change in ten years either?

Re: DIY Off-Grid Solar Power

#66

Post by devwastaken »

Syonyk wrote: post #17
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…

> Still not sure how I’ll ultimately get around this. If it's portable, your option works well. For year round off grid use, there's something to be said for sealed lead acid, or flooded lead acid - they don't care about being cycled while cold (capacity is down and the voltage sags a good bit), and as long as they don't get too deeply discharged, they don't freeze. A single panel, facing south, absolutely vertical,…

Hypothetically, for the lithium batteries, what if you made a big stainless steel vacuum wall insulated enclosure? Or just a metal box with r-60 value of foam around it?

The amount of heat needing to be generated can then be calculated based on the average temp over a longer period of time, and those batteries I don't imagine have to be "warm" exactly.

Re: DIY Off-Grid Solar Power

#67

Post by chana_masala »

Syonyk wrote: post #17
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…

> Still not sure how I’ll ultimately get around this. If it's portable, your option works well. For year round off grid use, there's something to be said for sealed lead acid, or flooded lead acid - they don't care about being cycled while cold (capacity is down and the voltage sags a good bit), and as long as they don't get too deeply discharged, they don't freeze. A single panel, facing south, absolutely vertical,…

Thanks for your post. I'm reading through some of your blog posts now - really great!

Re: DIY Off-Grid Solar Power

#68

Post by [deleted] »

zdragnar wrote: post #51
Syonyk wrote: post #39

Earlier quoted context omitted.

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.…

[deleted]

Re: DIY Off-Grid Solar Power

#69

Post by WalterBright »

Syonyk wrote: post #17
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…

> Still not sure how I’ll ultimately get around this. If it's portable, your option works well. For year round off grid use, there's something to be said for sealed lead acid, or flooded lead acid - they don't care about being cycled while cold (capacity is down and the voltage sags a good bit), and as long as they don't get too deeply discharged, they don't freeze. A single panel, facing south, absolutely vertical,…

Seems to me that if you want to solar heat a cabin, a solar panel is going around the horn. Design the cabin to be a solar collector, like a greenhouse.

Re: DIY Off-Grid Solar Power

#70

Post by diamondlovesyou »

devwastaken wrote: post #66
Syonyk wrote: post #17

Earlier quoted context omitted.

> Still not sure how I’ll ultimately get around this. If it's portable, your option works well. For year round off grid use, there's something to be said for sealed lead acid, or flooded lead acid - they don't care about being cycled while cold (capacity is down and the voltage sags a good bit), and as long as they don't get too deeply discharged, they don't freeze. A single panel, facing south, absolutely vertical,…

Hypothetically, for the lithium batteries, what if you made a big stainless steel vacuum wall insulated enclosure? Or just a metal box with r-60 value of foam around it? The amount of heat needing to be generated can then be calculated based on the average temp over a longer period of time, and those batteries I don't imagine have to be "warm" exactly.

What about summer? Those batteries also need to stay cool...
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