Solar power system for small cabin?

[Macchina]

I currently own a cabin in Northern Michigan and werew soon building a small guest cabin near it. I can run power to it but would love to make it self-sufficient.

We plan on running fans, charging phones, 2-3 LED lights, and MAYBE someday a small TV and DVD player. The cabin will be used at most 5 nights in a row but most likely 2 nights a week top.

It appears the solar industry is the online equivalent of a used-car salesman. It seems every review is fake, every blog is a cover, and it's very hard to research.

What should I be looking at for a solar panel system with a battery storage? How long does the battery last before needing to be replaced? Will a cold (Michigan) winter prevent the system from working?

 

[DocJD]

I'd just run the power to it . Unless money is no object and/or you are willing to research and DIY . Northern Michigan is not the best location for solar especially in winter . Could be done if no tree or hills in the way but you'd need a really enlarged collector . You could insulate and electrically heat your battery bank if the cabin is very cold . Depends on how bad you want to have it . Won't work unless sunny and kept clean of snow and leaves etc .

 

[shinyedges]

I live in northern Michigan, are you referring to the UP or northern lower peninsula?

We get less sunlight per year than virtually everywhere else on God's green earth. So, that said, if your planning on utilizing the cabin other than the few short months we actually get decent quantities of sun, solar probably isn't the best option. Maybe a combination of solar and wind could get you by if you have a large enough setup.

 

[Sid Post]

My friend and I run Tilapia over winter in a closed system (invasive species laws in Texas) on solar power. We have three electric water heater elements (direct drive), lights, and air pumps, and have to cut out panels on strong Sun days to keep the water temperature under 80F. We use 'Midnight Solar' controllers and 4 Duracell batteries, for 24V DC, and generally can run about a week (4~7 days depending on overcast conditions) before the batteries start to sag to the point where we look to turn stuff off. We generally run 400W to 600W under good Sunshine and ~125W on heavy overcast days. This year we are adding solar trackers to boost panel output so we can run fewer panels.

Your enemy is short hours of daylight and dust (or shading) on a panel. One panel with dust, shade, bird droppings, snow, etc. will kill power on that entire chain of panels.

You seem to be describing a load greater than ours but, probably not twice as much. For your geographic location, you need solar tracking and a clear view of the sky for all daylight hours. You will also want a 48V system (8 batteries). For longer stretches of poor solar output, you can double your batteries, still running 48V. Hard mounted panels on your cabin aren't going to work for your situation. Solar trackers on a pole array are the way to go (6~9 panels @ 210~230W each).

Our home built tracker and new arrays are in the final prototype stage for this Winter. I'll try to get some pictures when my schedule allows it. One third the solar panel capacity will hit a solid 550 Watts now! When we get it tuned, one third the panels should exceed our previous capability. Yes, solar trackers and moving farther away from the trees to stop late day shading has made a huge difference (we compensated with a lot of extra panels for a less than optimal panel layout - often referred to as being 'over paneled'). The quick and dirty method of adding more panels allowed us to cheat because we had 'extra' panels and needed our 'time' for other things. Now we have 'time' so, a better and more efficient panel layout is in work.

 

[Sid Post]

…

It appears the solar industry is the online equivalent of a used-car salesman. It seems every review is fake, every blog is a cover, and it's very hard to research.

What should I be looking at for a solar panel system with a battery storage? How long does the battery last before needing to be replaced? Will a cold (Michigan) winter prevent the system from working?

Its sort of like knife buying when you are a total newbie. My friend in the Air Force bought a hollow handle 'survival' knife in Taiwan to get him out of a C-130 and survive with it if he crashed in Central America somewhere. I, being a desk-bound adventurer, with the physique to prove it, used my weakling arms to flex the handle and blade bare-handed. I pulled out my CRK "One-Piece" and challenged him to do the same, then take it out to a tree in the yard and do chin-ups on it. His 'survival' knife did not see the light of day again to my knowledge and I left him with the CRK, believe it was a Shadow, and he carried from that point forward until retirement.

Batteries:

If you take care of them, they will last a very long time. I think we are at ~7 years with ours. We actively maintain them too. Our batteries have worked through a week of low-20's without issue.

Buy good batteries and take care of them! Big Box Store batteries will not serve you well. Neither will Marine batteries, at least the ones I'm familiar with.

6V Duracells are serving us well. We buy enough batteries to get a commercial rate but, if you do a 48V system you should get a commercial rate too! Seems like our batteries run ~$80. Add a battery hydrometer and some distilled water and you should be set for a long time, assuming you get more distilled water occasionally.

Check out Midnight Solar as a place to start for your needs or, at least some options.