While there are many types of solar technologies, the most efficient for our area are photovoltaics (PV) panels. These can be as simple as the small PV panel in a solar-powered calculator, or as robust as an array of solar panels powering your business.
It all sounds a little like Star Trek, but the earth is being bombarded with the sun’s photons. At any given moment, those photons carry 173,000 terawatts which is 10,000 times more power than we use across the entire planet. Most of that goes to waste, but we can harness some of that with solar panels. Solar panels are made up of tiny solar cells. Solar cells are made of layers of silicon. Photons knock electrons from one silicon layer to the other. These moving, charged electrons flow through a circuit, generating electricity.
Solar cells generate direct current (DC), but homes and businesses need alternating current (AC). To make this conversion, we connect solar panels to an inverter which converts DC to AC electricity we can use to power appliances and equipment.
For a slightly more nerdy explanation without getting too deep, check out this TED-Ed video.
Net metering vs. off-grid power
Net metering is a billing arrangement with the electric utility that credits solar energy system owners for the electricity they add to the grid. For example, during the day, the solar system will likely generate more electricity than the home or business needs. At night, the opposite is true. Net metering keeps track of the difference between the power generated and the power consumed. If there is a surplus of electricity, the utility will compensate you for that surplus. If your solar system does not produce enough electricity, you would be charged the normal rate.
Since there is a difference in what the utility companies charge and pay, it’s important that we design the system for your expected usage to maximize your value. When our consultants visit your home or business, we will ask about future plans and if electric demands are increasing or decreasing.
Currently in Maryland, for legitimate safety reasons it is not legal to use your solar panel system as back-up power when the utility grid is without power. The concern is that the solar panel system would back-feed the utility lines and pose a danger to the linemen. The only allowable way to use the solar system for back-up power is to have it feed, not your electric panel, but a battery system which then feeds isolated branch circuits.
By encouraging generation near the point of consumption, utilities can better manage their peak electricity loads which reduces system costs and strain on the electric grid.