Balance of System (BOS)
The balance of system contains these system parts:
- Solar Panels
- Roof Integration Equipment
To complete the full home solar installation, a net meter, an inverter, panels, and monitoring have to be added.
Grid-tied systems don’t require batteries. When the rooftop solar isn’t producing power, energy will be supplied via the grid. Solar-powered homes reduce how often you use utility-provided electricity.
Power plants supply energy to homes. The grid refers to a system of power lines that sends electricity from points A to B. If you are “going off the grid”, you no longer receive power from outside resources; your household generates it’s own power.
With a home solar installation, homes still use the grid (when the sun isn’t shining). Solar home systems are classified as being “grid-tied”. Grid-tied homes are eligible for a number of tax incentives and rebates. Check to see what you may be eligible for in your state.
Your home receives power from a local utility, which is carried via the grid. To install a solar power system, you’ll have to get permission to “interconnect” solar to your electrical grid network. Think of it as a merger between the two power sources. When you sign up for an install, your authorized solar dealer will handle all of these details.
A kilowatt-hour is a unit of energy.
1 kilowatt = 1000 watt-hours.
If you left a typical 60-watt light bulb on for an hour, you’d have used 60-watt hours (.06 kWh). You can calculate how much electricity any bulb uses by calculating watts to kWh.
Your electricity bill is based on how many kilowatt-hours are used. Solar power reduces these amounts, since the solar system will produce it’s own kilowatt-hours while the sun is out.
Each home has a utility meter that records how much energy is being used. At the end of each month, your utility company bills you for the amount recorded on the meter.
A net meter, on the other hand, is installed when you add solar to your home. As the solar system produces energy, it feeds electricity to the net meter. As long as there is electricity in the net meter, you won’t use electricity from your utility.
Reducing energy consumption from your local utility also reduces the recorded amount on the utility meter (meaning a smaller utility bill). And if you produce more solar electricity than your home uses, the amount on the utility meter will turn backwards. You only pay for the amount of energy consumed (hence the name, “net metering”).
Photovoltaic is the process of creating electric power from solar cells.
How is solar turned into a useable power supply? It’s all done with a solar inverter. The inverter turns direct current (DC) electricity into alternating current (AC) electricity. Your home may have one or several solar inverters installed.
A solar lease is exactly that—a legally binding lease. Within the lease, you will agree to the monthly payment amount and solar system size. The authorized dealer will not only install the system, but will also maintain it. Also included is a performance guarantee.
Solar Panels (also called Solar Modules)
Solar panels are made of “cells”. The cells are made of silicon and they absorb sunlight. The sunlight is converted into electricity (a photovoltaic effect). When you link multiple solar panels, they form “strings”; linked strings form “arrays”. An array connects to a solar inverter, which then provides electricity to your home.
Homes receive power from either a local source (ie: a power company). This source is called the utility; power is carried from there to your home via the grid.