One of my original plans for the tree house was to use it as an excuse to play around with a solar photovoltaic system. I eventually questioned the usefulness of this, since the tree house doesn't get a lot of direct sun, especially in the summer.
I decided to at least give it a try. I started doing a little research, and over the last several months I've accumulated some of the necessary components.
Initially I'd like to use the system to power some lighting. Looking around on the web a bit, I found some cheap-ish 12 volt LED lights on Amazon.
I had some old lead acid batteries around from another project that where never used. Unfortunately they had sat too long, and I couldn't get them to hold a charge. I picked up a sealed led acid battery locally from Portable Power Systems. It is bigger than what I need for lighting, but will give me some room to grow the system.
For the charge controller, I went with a Genasun 4 amp unit. It is small, inexpensive (relatively speaking), and supports MPPT charging.
I haven't ordered any solar panels yet, the prices seem to be changing rapidly. Since I have a few months before the trip, I'll wait and see if they continue to drop in price.
I built a wooden enclosure to house most of wiring for the system. I intentionally went a little overboard on this, making it more complicated than necessary. I just naturally like switches, meters, and complexity in general. I had fun doing all the wiring, for whatever reason I really enjoy that task.
The control panel supports disconnecting the solar panel(s), battery, and charge controller individually. It also allows you to check the incoming voltage from the solar panels, the battery voltage, and how many amps of load the system is supporting. Fun stuff!
I'm working on some lighting fixtures for the LED bulbs. Other than the solar panels, I still need pick up some wire, and a few connectors.