this post was submitted on 10 May 2025
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I just found out I can buy a decent 400W solar panel in the local hardware store for around 90€ these days.

Are there people around with experience in off-grid solar? There is quite some supply in cheap MPTT charge controllers on the internet. And I can't afford a 700€ power station. But I would be able to buy a few power tool batteries or one of the lead-acid batteries people put in their caravan. Are there projects building a power station myself? Is this even worth it?

Maybe someone alredy wrote a blog post with recommendations or findings and failures along the way. Or has something similar running at home?

(Thanks to the mods for steering me towards the correct community.)

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[–] [email protected] 3 points 1 week ago (2 children)

1st thing to do is to figure out what you need to power. Solar panels are way cheaper than charging and storage. Try to decide how much on-demand power during the dark part of the day you really need. If you can do most of what you need during the sunny part of the day, you can directly power stuff with no need for batteries. It may be that for your use case, you are better off buying 4 times as many solar panels, but no batteries.

Batteries account for 80-90% of total costs and energy invested in an off-grid solar system

https://solar.lowtechmagazine.com/2023/12/how-to-build-a-small-solar-power-system/

[–] [email protected] 2 points 1 week ago (1 children)

Listen to this guy, made a solar powered trailer/workshop and battery storage is the biggest limitation. If you get 3 days of bad weather the battery drains and you go offline. Or you spend tons of money over sizing the system and the batteries are wasted 95% time. Its a game of numbers and use cases.

[–] [email protected] 1 points 1 week ago (1 children)

What kind of workshop are you running? I've been intrigued by direct solar applications since learning about this place on this low tech mag article.

https://solar.lowtechmagazine.com/2023/08/direct-solar-power-off-grid-without-batteries/

[–] [email protected] 2 points 1 week ago* (last edited 1 week ago)

Its essentially my garage and workbench with tools. My home doesnt have a garage so I made one. I built a modest bench into the nose of the trailer and put the inverter, battery and equipment under it. There is a cell hotspot and raspberry pi that controls the vent fans, exterior lights, etc so its a fully self contained, mobile workshop I can take wherever and I control it all from a website and get solar analytics. I usually park it way out back on my property.

[–] [email protected] 1 points 1 week ago

Thanks. That is a good read.