Solar Panels And Inverters

Harnessing the power of the sun provides 12 volt power in even the most remote campsites

Many RV owners who like to camp in provincial or state campgrounds that have no electrical hook-ups can still use the 12-volt system in their motorhome or trailer. The 12-volt battery system in the camper will allow a certain amount of time before the stored energy is all used and the batteries fail to supply the necessary current after a few days. Years ago, some early types of refrigerators, water heaters, and furnaces did not require a 12-volt supply since they had a small flame called a pilot light that burned all the time, and the propane valve was manually turned on or off. The thermostats for these appliances where in the form of an inert gas inside a small diameter tube (called a capillary tube) that expanded when hot and turned off the supply of gas to the burner. When the gas in the capillary tube contracted as the temperature fell, the gas valve was allowed to open again and the pilot light would re-ignite the gas. This offered a crude form of temperature control.

Today's RVs are more dependant on having 12-volt power available. This means that there has to be some way to recharge the stored energy of the battery so that we can continue to use our lights, stereo, fans, and refrigerator, water heater and furnace. Why do the present day refrigerator, hot water heater, and the furnace need 12-volts? It is necessary for the electrical thermostat to indicate when to open the propane gas valve so that the gas can flow and be ignited by an electrical spark. Most refrigerators can be operated from the propane system, but we often forget that the temperature control mechanism and propane valves operate from the 12-volt system. Without 12-volts, our refrigerator would not operate on propane fuel as the valve would not open, the ignition would not spark, and the thermostat would not be able to control the temperature inside the food storage area.

Some RVers today use electricity provided by the power of the sun to top up their batteries. By adding solar panels to the roof of the RV, the energy created from the sunlight helps to keep their house batteries fully charged during daylight hours. Electricity can be generated by the panels whether it is summer or winter. Although, less is produced in winter as the sun is at a lower position in the sky.

Solar panels come in many shapes and sizes, but the most important thing is the power output that the panel can supply. Power is measured in watts. A 15 watt solar panel will supply 1.25 amperes of current to the 12-volt system under full sunlight to help trickle-charge a battery that is not being used. Often on overcast days, or if the RV is parked in the shade, full sunlight is not available so larger panels become necessary to collect more light. Solar panels are protected by a non-glare glass that prevents damage from one-inch hailstones falling at up to 50 miles per hour, and helps concentrate the light falling on the surface .
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