First, you should know that while solar power is an effective solution for many electrical power needs, simple systems deliver small amounts of power. While your home’s electrical outlets deliver what seems like unlimited electrical power to anything you can plug into them, electricians calculate expected electrical current needs and size your home’s electrical systems using variations of the formula: Volts multiplied by Amps equals Watts.
A 15 amp, 120-volt circuit in your home provides 1,800 watts of power. Conversely, powering an appliance using 1,800 watts divided by 120 volts draws 15 amps from the power grid. Solar-powered electricity is bound by the same rule. A typical 100-watt solar panel produces around five amps at 20 volts during the few hours per day they see direct sunlight.
Electrical energy production is limited in stand-alone solar power systems and fluctuates from peak power when exposed to full sunlight to zero production after sunset. That’s why most solar power systems utilize a battery bank to store excess energy produced during peak times for use after dark. A simple 12-volt system costing under $500 can power water timers, a small fan at times, vent system actuators, and minimal use of an LED light. Systems that pump water, provide heat, or keep multiple lights on throughout the night are complex and cost more.
