AKA Trickle Charge Economics
It blows my mind how resistant people are to solar power. There's an online community for Airstreamers where people share do-it-yourself ideas, and it's mind-boggling to see the invisible barrier people throw up against solar energy. I've read that solar power is "emotional", it's "green but not practical", it's frivolous, it's nothing like a generator, it's a Band-Aid on an infection. The metaphors are wildly inaccurate and clearly behind technology.
Thankfully, not everyone is like that! Many people make their Airstreams temples of sustainability, pushing the limits of green-living in a beautiful direction. Solar energy is so unbelievably cheap and easy, I just want to share it with the world. So here I go.
As mentioned before, Bessie has a deep-cycle battery to power her 12-volt system. Over time, a DC battery will discharge, which means its electrons flow from the positive terminal to the negative terminal. It is the battery's simple quest for equilibrium.
Harnessing this flow of electrons is what powers an electrical system. The longevity of a battery depends on how much it's used and its ability to recharge.
A constant trickle charge is the best way to maintain the health of a deep-cycle battery. A simple 15-watt solar panel will help restore the charge lost from powering a system (like interior lighting or a water pump). The solar panel sends electrons back to the positive terminal of the battery.
In the above photo, you see a 15-watt solar panel attached to the house roof. A few lengths of easy-to-disconnect wires connect to the battery in Bessie, which is located under the future bed...
In the photo below, the red plastic box holds the charge controller that protects the battery from a power surge from the solar panel. The grey plug connected to the blue battery fits into the black socket and powers the DC system. I leave it disconnected when not in use.
A side view, and maybe a better look, at the black power socket.
The wires from the black power socket are protected by PVC pipe that runs through the floor of the trailer and under the belly towards the battery box above the front hitch.
The wire in the above photo is the AC umbilical cord on the other side of the trailer. It is not part of the DC system which runs through the white PVC pipe.
At this point, the DC wires puncture the exterior skin of the trailer and emerge through the interior skin for regulation at the DC breaker box, located under the front window/dinette table.
Safe and sound and out of the way. The breaker box will eventually be covered by a wooden cabinet to protect against accidents.
The solar panel attached to Bessie in the first photos above sells for $55 online at www.siliconsolar.com and the charge controller is around $20.
A DC battery of 100 Amp-hours costs more than that, and if you only use the lights in your trailer when it's dark, and let the water pump do it's thing, you'll most likely not need much more than this panel to keep your DC battery above 80% charge for most of the year. If you are thoughtful about power usage, this is all you need to create a perpetually generating small electrical system. $200.
Disclaimer: Cloudy days will still give you electricity, just make sure you don't travel underground.
