A few months ago, I wrote about the process of selecting a solar electric system for our tiny house. We ordered our equipment from Backwoods Solar in late summer, and the installation was complete by early November, with my husband Brian doing all of the work himself. Today, I welcome Brian to tell about the process of installing our homestead photovoltaic system.
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We chose to install an off-grid photovoltaic system for our electrical needs, partly because we wanted an alternative to the coal-fired electricity of NE Missouri, but also because our home site is about ¼ mile from the road, and the cost of running power lines and poles would have been comparable to what we paid for our system. We had gotten a few different recommendations for Backwoods Solar, a small company based in Idaho, and decided to buy our system through them. We couldn’t be happier with our experience. They tailored our system to our needs and budget, and were always available for phone consultation and trouble-shooting along the way, which made all the difference for me. I have a limited amount of electrical wiring experience, but with their advice, some puzzling over manuals, and some help from my father-in-law, I was able to safely install this system. I would encourage anyone with similar skills to try it, or consider hiring an electrician to help you install it.
Here are our three PV panels or modules, mounted in front of our house on a homemade support structure. I chose to mount them here instead of on the roof because I didn’t want to put any holes in our roof or buy a mounting rack. Also, there was a certain amount of shade on the roof from nearby trees which I wanted to avoid. I set the permanent angle of the modules to a recommended average between the summer and winter angles.
Positive and negative and ground wires come out of each module and feed down to our combiner box that I mounted under the eave of our porch. Each module goes through a breaker and combines and from there, a single positive wire and negative wire lead into the house.
Here is where the heart of our PV system resides, on the wall of our mud room. If we had a bigger house, I would’ve installed it in the cellar or utility room, a bit more removed from our living quarters, but in a tiny house, you have to make do with the space you have! At the upper left is the charge controller, which makes sure the batteries are charged properly, and not overcharged once they are full. From the battery box, heavy duty positive and negative wires lead up to the inverter, the large white box in the upper center, which takes the DC current and converts it to AC, and from there it feeds into the gray breaker box which is what any house connected to the grid would have. Last but not least, the small digital display to the lower left is our Trimetric battery meter, which allows for very accurate monitoring of battery status. The battery bank is one of the most expensive parts of your system, and one of the most vulnerable to damage if proper charging is not maintained, so this is a critical component.
Inside the battery box, you can see our eight 6-volt Trojan batteries, connected in two parallel 24-volt strings. The box has a well-sealed hatch and a pipe leading outside the building, to safely vent off explosive hydrogen gas which is produced during charging.
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Thank you, Brian! I should note that we’ve been using our photovoltaic system for almost two months now, and it is truly amazing! Although I love the simplicity of living without electricity, it is so nice to be able to easily use a blender, or a laptop, or simply to turn on lights to see while you’re reading! We recently plugged in an energy efficient chest freezer, and will watch the system to see how it handles that extra load!