Solar Photovoltaic (SPV)

Solar Photovoltaic (Electric)

Solar panels silently convert light into electricity using what is known as the photovoltaic effect, all while using no moving parts and requiring little annual maintenance. The building blocks of solar lie in the photovoltaic cells themselves. Photovoltaic cells are constructed out of high-grade silicon, which reacts with photons from sunlight to produce a current of electricity.

A photovoltaic (PV) system is an assembly of components. These components include photovoltaic “cells,” which are framed into a case referred to as “modules.” These modules are arranged in a group (array) of solar “panels” (modules) combined together to generate power output as measured in units called watts.

1000 watts is one Kilowatt (KW), and 1000 Kilowatts is one Megawatt (MW). PV modules are rated in watts. This rating is useful for comparing PV modules. It is instantaneous output at a standard test condition. Weather, site characteristics, and efficiency losses are also taken into account to predict system output. The PV array wattage should not be confused with system annual performance or electric bill Kilowatt-hours (KWh), a unit of energy (power consumed over time).

The modules are held together with racks and fastened to the roof or secured to the ground. The system also includes at least one inverter. The inverter converts the electricity produced by the solar array into electrical energy compatible with traditional AC utility power. The system also includes a meter that is easy to read for monitoring and recording energy produced by the system in KWh units.

The panels have a factory warranty of 25 years and the inverters are warranted for 10 years. The equipment will most likely last longer, but the efficiencies will drop over time. We would recommend replacing the system at some point after the 30 year period.

Maintenance on these systems is notoriously minimal. The most important aspect of maintaining a large solar array is inspection and testing outputs at various points throughout the system. Both of these tasks help ensure maximized array efficiency.

Components of a Solar Array

Solar Module: Multiple solar cells are combined into a complete “solar module” that also includes a frame for the system, electrical interconnections, and mounting hardware.
Solar Panel: Multiple modules are assembled into a “solar panel” that is then secured to the roof or other structure.
Racking: The structure which is secured to the ground and the solar panels are mounted on is referred to as the racking.
Inverter: An inverter, usually installed on the outside of your home, takes the DC output from the cells and transforms it into usable AC power.
Electric Panel: Electricity will be sent from the inverter to your electric panel (or “breaker box”). Your meter will spin backward when your solar system produces more electricity than you need and will spin forward at night or on cloudy days.
Utility Grid: The utility grid refers to the electricity going to/from your electric provider. When you go solar, you will send back to the grid the electricity that you produce in excess of your consumption, and use grid electricity at night or on cloudy days.