I wanted a light in my backyard that could be turned on and off from either the back door or from an out building, I could have run about 150 foot wire for a 3-way switch or I could come up with an off the grid remote switching light. I chose the later because I had not done it before.
First I gathered the components , mostly from Ebay.
First I found an 12v off road light bar -22 inch led 126 watt $40
Then a 12 volt deep cell battery for a gate opener 18ah $30
12V On - Off Remote Control Wireless 12V Output Relay Switch 15A $30
I then visited Harbor Freight and got a 45 watt solar panel kit with charge controller $120
Northern Tool a battery box since the electronics are not weather proof and a terminal strip. $12
Step 1: Wiring the Light and Remote Control
Next the remote and light were wired per the included instructions.
Step 2: Installing the Light
Next the LED light bar was mounted on an old dish network post and aimed at the back yard. The battery box and remote switch were attached to the light bar.
The light installation was complete.
A remote was hung of a hook by the back door and the other one is in the outbuilding by the door.
Step 3: Solar Panel Installation
Next the Harbor Freight solar panel was setup next to the battery box. The instructions were followed and the charge controller was attached to charge the battery.
The solar panel is over sized for the light system, but the panel is not placed in full sun and is shaded by the residence till about noon each day.
So far the system is keeping the battery at 100%. The light is used less than an hour a day (100 watt per day) and the solar panels can output over 270 watt in full sun so being in the shade part of the day I am getting enough power to keep the battery fully charged.
The "secret" to off the grid power is define your need.
Then install battery capacity to operate the devices for the time needed plus a safety factor for cloudy or short days (winter). At least 2 day and if affordable 3 or more.
After you have a successful system running on battery power consider the charging system. You need a charging system capable of charging the battery to full charge in 4 hours or less. This will keep the battery charged even on cloudy days. If you cannot afford that many panels consider a backup generator (gasoline or propane) to charge the batteries when the sun is not cooperating. You could also charge the batteries off a vehicle but that is very inefficient.
Will see how well this works and will consider expanding to other systems is the house, one system at a time that way and modularly so that if one items fails I am not powerless. If it is an emergency components can be moved to different systems to keep life on an even keel. Will probably work on the home heating system next. The system is propane, but the blower is electric and the controls.
Also am thinking about installing wifi security camera by the driveway to record license plate numbers of the vehicles entering and leaving. The current eave mounted cameras do not have the detail to read plate numbers. The camera could be installed in a blue bird house and the battery and solar panels could be installed 20 to 30 feet away so as not to alter of the surveillance. (thieves steal security cameras)