Traditional Residential Electricity vs How Home Solar Works
Most of us are used to getting electricity from a local power company with a tiny fraction of people that live “off the grid” electing to not use electricity at all. For the bulk of us that do use electricity, the local power company measures how much electricity you use with a power meter that typically gets recorded once per month so the company knows how much to charge you. Many power companies have a “tiered” pricing structure that charges you more as you use more. Power is measured in something called kilowatt hours and abbreviated as kWh and is the unit used for billing customers.
A residential solar panel system makes electricity through devices called solar panels. These solar panels converts light to what’s called “direct current” or DC power. DC power is typically what stored in batteries such as those you might use in toys or flashlights. This form of power must be converted to “alternating current” or AC power in order to power various electric appliances and devices in your home. Therefore part residential solar panel cost includes a component called an “inverter,” which has a range of prices depending on the size of the residential rooftop solar panel array.
This inverter is wired to the home electrical panel which routes electricity through your house using “circuit breakers” which are switches that shut off if power is shorted out or overloaded. When you add home rooftop solar panels a circuit breaker is added to the main service panel which allows power to flow both into and out of your home, as in the case where your residential solar panels produce more electricity than you use. The excess power goes back to the power company, the meter reverses direction, and during these times your power bill is either being reduced or you are making money selling your excess power.
Intuitively solar panels only produce power during daytime when the sun is shining on your home solar panels. At night typically the above scenario is reversed and you draw or use power from the power company the same as you have been. However you have built up credits with the power company during daylight hours making the power company act like storage for the power you generated during the day.
Home solar panels produce electricity based on daylight, not the heat of the sun. This means residential solar power makes sense even in colder climates. However the amount of power produced depends on the intensity of the light making direct, unobstructed sunlight produce the most power. That’s why in North America home solar panel cost depends on how much daylight your location receives and the amount of space your home rooftop has that is facing south with no shade.