diy solar

diy solar

Off grid home in Northern Minnesota

Selien Morawitz

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Joined
Mar 24, 2021
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Come summer of 2021, I will be building an off grid cabin that we will be living in full time. We live an area where cell service is not available and the only internet source is by satellite. Because of the location, a solar company will not install a system for us and told us we will have to build a system ourselves. We are interested in building a 24 v - 3kw system. The questions I have is how many solar panels (what size) would be needed? what other sizes I would need for other materials as well such as : charge controller, inverter, etc...
 
Welcome to the forum.

You're asking questions that require more input.

Two planning steps:

1) Link #5 in my signature for your available solar. Link #6 if there's not a town nearby.
2) Link #1 in my signature to conduct an energy audit.

Failure to do either of those results in a system that won't work or costs too much.
 
Welcome to the forum!
Aren't you brave! The cold and snow of a northern winter will be a special challenge for you!

Looks like you've already given some thought to what you'd need.
Here is Will's recommended 4Kw system:

Take a look at the Solar Blueprints link above too. There are other systems described.
You should also view some YT videos to familiarize yourself with how to DIY if you haven't already.
I also found Will's book very useful as an intro to the whole Solar business. It's written mainly for RV's but most of the stuff is directly applicable to any off-grid system.
 
OFF-TOPIC - What are you going to do for heat/hot water? Look at gasification boilers for super efficient wood burning heat. I love the concept, but have no application for that - yet!
 
Solar off-grid is all about the battery. I'm a firm believer in first sizing your batteries to what energy (watt hours) you need (#1 in @snoobler's list) and then sizing the PV (photovoltaic, i.e. solar panels) based on the battery bank and your solar insolation (#5 in @snoobler's list). Then size your inverter based on the maximum power (watts) you will need at any one time.

Bottom line, main point: Before you do anything else, figure out your energy needs, and how much battery you need based on that energy.
 
Hopefully you can harvest wind. You will need it in the winter. Perhaps run small generator a few hours a day to charge batteries.
 
Come summer of 2021, I will be building an off grid cabin that we will be living in full time. We live an area where cell service is not available and the only internet source is by satellite. Because of the location, a solar company will not install a system for us and told us we will have to build a system ourselves. We are interested in building a 24 v - 3kw system. The questions I have is how many solar panels (what size) would be needed? what other sizes I would need for other materials as well such as : charge controller, inverter, etc...
Selien, I live in NE Minnesota, just off the North Shore of Lake Superior. Most areas up here match, no cell service, no ground based internet. Couple things to consider: all batteries do better to be kept above 32°F ideally (I don't put water on the floor, at the edges of my house); BiFacial solar panels are newer technology, great when you may have fewer than 5 days of sunshine, in winter, but have prevelent white reflectivity EVERYWHERE; road access is important also?
 
Hey Wit, looks like we are in the same area - I have a place up the Gunflint I’ve been renovating and adding solar. If you wanted to chat I’d be interested in talking shop and learning more about the ins and outs of the area. DM me and we can connect if you’re interested.
 
Two things to remember is easy ability to clearing snow off and color of panel frames. I'm also in Northern MN and have mine on top of pole mounts and use floor squeegee to clear the snow off. It's also really beneficial to use panels with black anodized frames and not natural aluminum color. I have two sets of panels on same top of pole array, one set with black frames and the other natural aluminum. In winter the sun frequently melts snow/ice off the cells themselves but will instantly refreeze on the natural aluminum frames. This builds up enough that it starts blocking all the bottom portions of the panels in that set. With the black frames this does not happen since the sun it able to heat that black aluminum up enough preventing the ice buildup.
 
Thanks, Rhino - that’s a great tip I never would have thought of on my own! Mine have the aluminum frames, but I’ll definitely be painting them before the end of the summer. Fortunately the south side of my place is situated next to the hill/ridge line so I can reach it pretty easily. I thought about pole mounting them - what made you go that route?
 
I pole mounted mainly because they are out in a field that is mowed for hay and also grazed by sheep and goats. I could just see goats jumping up and down on panels if they were anywhere near the ground ;)
 
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