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DIY Off-Grid Solar Power

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Re: DIY Off-Grid Solar Power

#121

Post by jacquesm »

DyslexicAtheist wrote: post #120
jacquesm wrote: post #99

Earlier quoted context omitted.

He has a point, but there is a thing you can do to offset some of this: read all of the comments. Plenty of times there will be someone in the comments pointing out what's wrong in the videos. The problem with Lithium Ion installations of any size is that the batteries are inherently dangerous and mistakes can easily set you back more than you saved on the whole thing. Unlike say your car where as long as you stay aw…

very much with you and GP on this. the route I personally take is to learn with small trials and error of what comments and advise is good and what is silly or outright dangerous. Places I frequent for such advise though aren't YT videos but forums where it's easy for others to call out silly ideas (which isn't always the case on YT). YT is at best a gateway to deeper content such as explosion-charts, repair and main…

I would highly recommend battery university, they have excellent content:

https://batteryuniversity.com/

Re: DIY Off-Grid Solar Power

#122

Post by Retric »

driverdan wrote: post #113
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…

LiFePO4 batteries can be stored and used below freezing, they just shouldn't be charged. All you have to do is turn the system off when you're not there.

In most areas keeping them underground can get around this, you can also use a backup heater and temperature probe before charging them.

Re: DIY Off-Grid Solar Power

#123

Post by jacquesm »

bregma wrote: post #102
i_am_proteus wrote: post #89

Earlier quoted context omitted.

Yep. Unless you've got running water or a high cliffside for wind, the best off-the-grid heat source for cold climates is an acre of woods and an axe. Insulation, too. A lot of sheds and cabins (and single-family homes) could do with more. Saves on cooling bills in the summer, too.

I live on 25 ha of forest, have an axe and saw, and heat with wood. Let me tell you: you want to use the saw for everything but splitting. Axes are fine for burly cavemen. Anyway, in a cold climates like mine an acre would not be enough to keep you warm because trees grow slow when it's winter six months out of twelve. It takes a lot of wood to keep you warm, and one tree gives surprisingly little wood. After a handf…

By the time you get to 100 acres you can basically heat your house with the stuff that blows over in storms and the remainder can yield a nice cash crop every couple of years, giving space for the other trees to grow. Personally I'd prefer a chainsaw for anything but the most incidental cutting, and a hydraulic woodsplitter (rented) to get the job of preparing firewood for a while year done in a short time.

Re: DIY Off-Grid Solar Power

#124

Post by jacquesm »

stephen_g wrote: post #45
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 alre…

Victron is top of the line stuff and will serve you well. On marine installations it's not rare at all to see their inverters outlast the hull.

Re: DIY Off-Grid Solar Power

#125

Post by angularbot77 »

jacquesm wrote: post #94
CorrectHorseBat wrote: post #84

Earlier quoted context omitted.

5kW of panels don't produce 5kW in winter, that's the issue I guess.

Correct, they will produce more. Solar panels produce the most power on cold winter days. The 'rated power' is for 20 degrees ambient at full (90 degrees, no cloud) incidence at sea level.

Problem is, the sun doesen't necessarily rise above the horizon for weeks in northern countries

Re: DIY Off-Grid Solar Power

#127

Post by Epa095 »

adrianN wrote: post #83
Epa095 wrote: post #79

Earlier quoted context omitted.

Is 5kW not enough to heat the cabin? I guess it must be really cold where you are. Modern heat pumps should unproblematic handle -25°C (air to air), and provide 4-5kWh of heat for each kWh of power used.

Which heat pump reaches that kind of efficiency when the temperature differential is so high?

Good point, I did not think about the fact that the effeciency went down. But it seems to me (as a noob) that modern heat pumps specialising in low temperature conditions still can get around 2.5 at -25°, which gives you more than 10kWh of heating at 5kW, which is quite a lot.

Re: DIY Off-Grid Solar Power

#129

Post by jacquesm »

angularbot77 wrote: post #125
jacquesm wrote: post #94

Earlier quoted context omitted.

Correct, they will produce more. Solar panels produce the most power on cold winter days. The 'rated power' is for 20 degrees ambient at full (90 degrees, no cloud) incidence at sea level.

Problem is, the sun doesen't necessarily rise above the horizon for weeks in northern countries

Yes, in locations like that you will have to use some other solution for those periods. Maybe wind power. Battery storage will not last long enough unless you have an absolutely massive setup that would not be cost effective the rest of the year.

I had 48KWh worth of storage, 2500 W worth of wind and another 5000 W worth of solar. This was in Northern Ontario. Until we added the windmill we fairly regularly needed the generator, after we added the windmill the generator just sat there gathering dust.

Re: DIY Off-Grid Solar Power

#130

Post by lazide »

WalterBright wrote: post #69
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,…

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.

You’d still need backup heat production (heat pump, or wood burning, or fossil fuel, or electrical off batteries) for the inevitable month long ‘gray and cold’ stretches, or you’re gonna freeze.

Single purpose but not reliably there heat capture methods add cost and maintenance.

It’s often more cost effective to have a general purpose method that while not as efficient in one case is generally more overall (cost) efficient.

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