The two solar panels are in parallel because they output close to the voltage of our system of 24V. While we would get the same amount of power theoretically by putting them in series (creating a combined voltage of 50-60V), there would be more efficiency losses from stepping down the voltage.
We terminated each of the two wires from the panels with our own solar connectors. The issue was that we had to pay $160 for a crimper, and each connector is around $5. Attributing to the fact that these were the first 4 connectors we ever made, 2 of them came out bad and we are only functioning on 1 panel at the moment, until we decide what we want to do. We either continue using these connectors and wait for the order or come up with another way.
Anyway, the connectors are two female keyed and two male keyed Tyco solar quick connects found on page 9 of this Tyco - Solarlok catalog.
Keyed means that only those marked with the same "key" can connect to each other. They literally have a slot which prevents the connector of the other type from going in. This can be helpful in preventing accidental connection of a positive and a negative wire from connecting to each other, causing a short circuit. This creates a low resistance path for electrons to flow. If the wire is not thick enough to withstand the current output from whatever is short circuited, then it will heat up too fast and burn.
Those were purchased off the Mouser website.
Our junction box is an outdoor rated box from Home Depot. We drilled four 1/2 inch holes in the sides and attached the male connectors. They come with a rubber seal.
So this box is up there near the solar panels. Two wires from each panel connect to the box. Then the connection creates the seal between the wires and the rainy, snowy, sunny outdoor environment which would otherwise degrade regular wire too fast. It is an electrical code requirement to do so, and is also a good idea. However, these connections are not the only way to isolate a wire connection from a harsh environment.
That box is connected to a pipe, which runs along the top of the tool shed, to the back of the garage to another box.
From that box it goes through the wall and comes inside the breaker box.
Just as with the batteries, we dedicated a positive and a negative bus bar to the solar panels so that we can connect other components to them.
There is a 50Amp DC fuse / switch on the positive wire from the panels, right before it connects to the bus bar. That is so if we need to, we can disconnect the power for maintenance.
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