Backup Generator AKA: The gas guzzler
Off-grid solar-electric systems can be sized to provide electricity during cloudy periods when the sun doesn’t shine. But sizing a system to cover a worst-case scenario, like several cloudy weeks during the winter, can result in a very large, expensive system that will rarely get used to its capacity. To spare your pocket, size the system moderately but include a backup generator to get through those occasional sunless stretches.Engine generators can be fueled with bio diesel, waste oils (Including WVO, WMO, Gear Oil) petroleum diesel,gasoline, or propane, depending on the design. These generators produce AC electricity that a battery charger (either stand-alone or incorporated into an inverter) converts to DC energy, which is combustion engines, generators tend to be loud and stinky but a well-designed solar-electric system will require running them only 20 to 100 hours a year.
