Glossary, 101 terms

Solar terms explained in plain English

Every term here links straight to the calculators that use it, so you're never stuck with a definition and nowhere to go next. Jump to a letter or search for a specific word.

Jump to: A B C D E F G H I J K L M N O P Q R S T U V W Y Z

A

AC coupling Adjustable-rate PPA Aggregator (community solar) Ampacity Anti-islanding Array Autonomy (off-grid) Azimuth

B

Balance of system (BOS) Ballasted mount Battery management system (BMS) Bidirectional inverter Bifacial panel BIPV (building-integrated PV) Buy-all sell-all Bypass diode

C

C-rate Capacity factor Charge controller Clipping loss Combiner box Community solar Curtailment Cycle life

D

DC coupling DC-to-AC ratio Degradation rate Demand charge Depth of discharge (DoD) Derate factor DERMS Disconnect switch

E

Energy storage system (ESS) Escalator clause (PPA) Export limit

F

Fixed-rate PPA Flash test rating Float charge

G

Ground fault Grid parity Grid-tied system

H

Hotspot (panel) Hybrid inverter

I

Interconnection agreement Inverter clipping Investment Tax Credit (ITC) Irradiance

J

Junction box

K

kWh vs kW

L

Levelized cost of energy (LCOE) LFP battery Load profile

M

MACRS depreciation Microinverter Monocrystalline MPPT (maximum power point tracking)

N

Nameplate capacity Net billing Net metering Net metering true-up NMC battery

O

Off-grid system Optimizer (power) Orientation (solar)

P

Parallel wiring Performance ratio PID (potential induced degradation) Polycrystalline Power purchase agreement (PPA) PVWatts

Q

Quick-mount racking

R

Racking system Rapid shutdown device Rate of return (solar) Reactive power Rebate Renewable energy certificate (REC)

S

Self-consumption rate Series wiring Shading loss Snow load Soiling loss SREC State of charge (SOC) State of health (SOH) String inverter

T

Tilt angle Time-of-use (TOU) rate Total cost of ownership (TCO) Tracking system Transfer switch True-up period

U

Usable capacity Utility interconnection

V

V2H (vehicle-to-home) V2G (vehicle-to-grid) Voltage drop

W

Wattage vs wattage-hour Wire gauge

Y

Yield (specific yield)

Z

Zero export

Questions

Frequently asked

What's the difference between this glossary and a regular dictionary?

Every term page links to the actual calculators that use it, so you can go from "what does this mean" to "what's my number" without leaving the site. A dictionary just gives you a definition and stops there.

I'm not sure which term I need. Where do I start?

Use the jump-to-letter bar above, or the search icon in the header to search by keyword. If you're new to solar, terms like net metering, system sizing, and inverter come up the most in a typical quote or utility bill.

Are these terms specific to the US, or do they apply in Canada too?

Most terms are universal to how solar and battery systems work. Where policy differs, like net metering rules or tax credits, the term page notes the US and Canadian specifics separately.