Discover Solar 2019 Glossary

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Balance of system

In a solar PV system, everything in addition to the solar panels: wiring, switches, mounting system, inverters, possibly optimizers and possibly a battery bank with charge controller

Cash flow positive

A situation in which money coming in is greater than money going out over a time period

Efficiency Utility

Generates energy through savings that displace energy consumption

Green House Gas (GHG)

Gases in the air that trap energy from the sun. Major ones include water vapor, carbon dioxide, and methane


The production and discharge of something, especially gas or radiation.

Installed watt

Term used when referring to the total price of a solar PV system


An apparatus that converts direct current into alternating current


The amount of solar radiation received per unit area by a given surface, expressed in kW/ m² (approximately 65 ft2 or 6M2 per kW of PV, the area occupied by 3 typical panels/modules)

Kilowatt (KW)

1,000 watts

Levelized Cost of Electricity / LCOE

Measures the cost of a power source in a consistent way to enable comparison of different methods of electricity generation

Net metering

System in which renewable energy generators are connected to a power grid; surplus power is transferred onto the grid, and customers offset the cost of power they draw from the utility

Net zero

 A building in which the total amount of energy used annually is roughly equal to the amount of renewable energy generated on site

PACE: Property Assessed Clean Energy

Financing for energy and efficiency available through participating municipal governments. Loans are repaid through property assessments, as an addition to the owner’s regular property taxes

Panel efficiency

The portion of energy in the form of sunlight that can be converted via photovoltaics into electricity

Photovoltaic (PV)

Utilizes the voltage created when radiant energy falls on the boundary between two different semiconductors)

Solar Cell

A composition that allows particles of light to knock electrons free from atoms, generating a flow of electricity.

Solar panel

A combination of individual solar cells (otherwise known as modules)

Watt hour

Electrical energy equivalent to a power consumption of one watt for one hour