Speak solar fluently.
AC
Alternating current; current direction varies periodically.
AC coupling
Connection of generation and storage through an AC-side architecture.
AHJ
Authority having jurisdiction over applicable approval or enforcement.
Ampere
Unit of electrical current.
Anti-islanding
Protection against unintended energization of an isolated utility section.
Apprenticeship
Structured training/employment requirements that can affect incentive qualification.
Arc fault
Unintended electrical arcing condition.
Array
Group of PV modules operating as a generating system.
As-built
Record reflecting the installed configuration.
Azimuth
Horizontal orientation relative to a stated directional convention.
BESS
Battery energy storage system.
BOS
Balance of system; supporting equipment beyond primary generating modules.
Backup Switch
Tesla backup isolation equipment for supported configurations; utility approval matters.
Backup reserve
Configured battery energy allocation for outage readiness under supported operation.
Ballast
Weight used as part of a mounting design; suitability needs structural review.
Bonding
Connection of conductive parts to establish required electrical continuity.
CAPEX
Capital expenditure.
Capacity factor
Actual energy divided by energy from continuous rated output over the same period.
Cash flow
Money paid or received during a period.
Cell
Basic photovoltaic semiconductor device.
Clipping
Limiting output when available power exceeds an applicable output limit.
Commissioning
Documented checks and setup verifying intended operation by authorized personnel.
Conductor
Material or component intended to carry electrical current.
Conduit
Raceway used to protect and route conductors under applicable requirements.
Continuous power
Power supportable continuously under stated conditions.
Credit transfer
Permitted transfer of eligible tax credits under applicable law and procedures.
Critical loads
Selected equipment prioritized for continued operation during disruption.
Current
Rate of electric charge flow.
Curtailment
Intentional reduction of otherwise available generation or delivery.
Cycle life
Cycle endurance under specified test conditions and end-of-life criteria.
DC
Direct current; charge flows in one direction.
DC coupling
Connection of generation and storage through a DC-side architecture.
DC/AC ratio
Array DC nameplate power divided by inverter AC nameplate power.
Degradation
Change in performance or capacity over time and use.
Demand charge
Charge linked to measured or defined power demand under a tariff.
Demand interval
Time window over which a tariff measures or averages demand.
Demand ratchet
Tariff rule linking billed demand to previous-period demand or another threshold.
Disconnect
Device or means for isolating specified circuit connections.
Discount rate
Rate used to convert future cash flows into present value.
DoD
Depth of discharge; fraction of reference capacity withdrawn.
Domestic content
Applicable origin/content requirements under particular incentive rules.
ESS
Energy storage system.
Elective pay
Mechanism available to certain eligible entities for qualifying credits, subject to current rules.
Energy
Quantity that can be transferred or stored and used to do work.
Energy charge
Charge based on purchased energy, typically in kWh.
Export
Electricity sent from a site to the utility under approved conditions.
Fixed charge
Recurring charge not directly proportional to current-period energy use.
Flashing
Water-management detail around a roof penetration.
Frequency
Cycles per second, measured in hertz.
Gateway
System equipment providing specified control, metering and isolation functions; model matters.
Grid-following
Control capability referencing an existing voltage/frequency waveform.
Grid-forming
Control capability establishing voltage and frequency for a supported electrical island.
Ground fault
Unintended connection or current path to ground or grounded parts.
Grounding
Connection to earth under the applicable electrical design.
Hertz
One cycle per second.
Hybrid inverter
An inverter supporting specified combinations of generation, storage and loads.
IRR
Discount rate that makes a defined cash-flow series have zero NPV; some series have unusual or multiple solutions.
Imp
Current at the maximum power operating point.
Insolation
Solar energy received per area over a period; units and time basis must be stated.
Interconnection
Approved electrical connection between a generating/storage system and the utility.
Internal certification
Company-issued learning credential under published assessment requirements.
Interval data
Metered usage or demand for successive time windows.
Inverter
Power electronics converting DC electricity into AC.
Irradiance
Solar power arriving per unit area, commonly W/m².
Isc
Short-circuit current under specified test conditions.
Islanding
Operation of a portion of an electrical network separated from the wider utility.
Kilowatt
One thousand watts; a power unit.
Kilowatt-hour
Energy transferred by one kilowatt over one hour.
LCOE
Levelized cost of energy under stated lifetime production and cost assumptions.
LOTO
Lockout/tagout; controlled hazardous-energy procedures performed by authorized personnel.
Lease
Contract granting use of an asset under defined obligations.
Load profile
Electrical power demand plotted or listed over time.
Load shedding
Removing or deferring loads to remain within operating limits.
Load shifting
Moving energy consumption to different periods.
MACRS
Modified Accelerated Cost Recovery System; tax depreciation framework requiring current project-specific advice.
MPPT
Maximum power point tracking; control that seeks available PV power.
Megawatt
One million watts.
Megawatt-hour
One thousand kilowatt-hours.
Microinverter
Module-level inverter architecture; exact supported configuration varies.
Module
Packaged assembly of photovoltaic cells.
NABCEP
Independent renewable-energy credentialing organization; this academy does not issue its credentials.
NPV
Net present value; discounted net cash flows including initial investment.
Nameplate rating
Manufacturer’s rated characteristic under stated conditions.
Net metering
Tariff arrangement accounting for eligible imports and exports; details vary.
Nominal energy
Rated energy under manufacturer-defined conditions.
O&M
Operations and maintenance.
OPEX
Operating expenditure.
Ohm
Unit of electrical resistance.
Ohm’s law
Relationship V = I × R in an applicable resistive circuit.
One-line diagram
Simplified electrical schematic showing principal system relationships.
Optimizer
DC power electronics that adjust a module or group operating point.
Overcurrent protection
Protection against excessive current using appropriately selected devices.
PPA
Power purchase agreement; contract for energy under defined terms.
PPE
Personal protective equipment chosen for the task and hazards.
PTO
Permission to operate issued through the relevant utility process.
PV
Photovoltaic; conversion of light into electrical energy.
Panel
Common term for a photovoltaic module; clarify usage.
Parallel
Connection in which simplified branch currents add at shared voltage.
Peak shaving
Reducing a relevant demand peak with controls, storage or load management.
Performance ratio
A normalized performance indicator whose definition and reference conditions must be specified.
Performance warranty
Manufacturer’s specified performance commitment under stated conditions.
Power
Rate of energy transfer.
Power factor
Ratio of real power to apparent power in AC systems.
Powerhub
Tesla’s fleet/system monitoring platform; access and capabilities depend on role.
Powerwall
Tesla’s branded energy storage product family; model and regional documentation matter.
Powerwall 3 Expansion
Compatible energy expansion equipment; do not assume it adds a separate full inverter.
Prevailing wage
Applicable wage requirements affecting certain incentive qualification.
RMA
Return merchandise authorization process for applicable equipment service.
Racking
Structural mounting system for modules.
Rapid shutdown
A code-related PV hazard-control function with defined scope; not proof that all energy is absent.
Resistance
Opposition to electric current in a basic circuit model.
Round-trip efficiency
Energy returned divided by energy supplied over a defined storage cycle.
SOC
State of charge; estimated stored energy relative to a defined reference.
SOH
State of health; estimated battery condition relative to a defined reference.
STC
Standard test conditions used for module rating; not a promise of field output.
Section 48E
Federal clean electricity investment credit provision; eligibility and timing must be verified.
Self-consumption
Use of on-site generated energy at the site.
Series
Connection in which simplified element voltages add along a common current path.
Shading
Obstruction of sunlight reaching an array.
Simple payback
Stated investment divided by assumed constant annual net benefit.
Single phase
An AC supply arrangement with one fundamental phase waveform.
Soiling
Deposits on module surfaces that can reduce received light.
Specific yield
Energy produced per unit rated capacity during a stated period.
Split phase
A center-tapped single-phase supply arrangement; verify actual service voltage.
Starting load
Power/current demand associated with equipment starting.
String
Modules electrically connected in series.
String inverter
Inverter architecture serving one or more module strings.
Surge power
Short-duration power capability under stated conditions.
TOU
Time-of-use pricing; rates vary across defined time windows.
Tariff
Utility’s applicable pricing and service rules.
Tax credit
A qualifying reduction in tax liability under applicable rules.
Tax deduction
Amount reducing taxable income under applicable rules; not identical to a credit.
Temperature coefficient
Specified change in a property per degree of temperature change.
Tesla One
Tesla’s professional workflow app; authorization and current process apply.
Three phase
An AC arrangement with three phase waveforms separated by 120 electrical degrees.
Tilt
Angle of a module surface relative to horizontal.
Usable energy
Energy available within stated operating limits and conditions.
Vmp
Voltage at the maximum power operating point.
Voc
Open-circuit voltage; voltage when no output current flows.
Volt
Unit of electrical potential difference.
Voltage
Electrical potential difference between points.
Watt
Unit of power equal to one joule per second.
Workmanship warranty
Contractual protection relating to installation work within stated scope.
kVA
Kilovolt-amperes; apparent power, distinct from kW.