Solar & Energy Glossary
Comprehensive guide to solar energy, ESS, backup power, and energy management terms—organized by topic for easy reference.
Solar Energy Basics
PV (Photovoltaic)
Technology that converts sunlight directly into electricity using solar cells. PV panels are the core of solar energy systems.
Solar Panel / Module
A collection of photovoltaic cells assembled together to generate electricity from sunlight.
Solar Array
Multiple solar panels connected together to increase total power generation capacity.
Monocrystalline
High-efficiency solar cells made from single-crystal silicon, recognizable by their uniform dark appearance.
Polycrystalline
Solar cells made from multiple silicon crystals, typically less expensive but slightly lower efficiency than monocrystalline.
Thin-Film Solar
Lightweight, flexible solar technology using thin layers of photovoltaic material, ideal for specific applications.
Bifacial Panels
Solar panels that can capture sunlight from both front and back sides, increasing energy production.
Solar Irradiance
The amount of solar power received per unit area, measured in watts per square meter (W/m²).
Peak Sun Hours
The equivalent number of hours per day when solar irradiance averages 1,000 W/m², used to calculate expected energy production.
Energy Storage Systems (ESS)
ESS (Energy Storage System)
A system that stores energy for later use, typically using batteries. ESS is crucial for solar and backup power solutions, enabling energy independence and grid resilience.
Lithium Battery
A rechargeable battery technology commonly used in modern ESS for its high energy density, long cycle life, and low maintenance requirements.
Lithium Iron Phosphate (LiFePO4)
A type of lithium battery chemistry known for exceptional safety, long life cycles (5,000+), and thermal stability.
BMS (Battery Management System)
Electronics that manage and protect battery packs by monitoring voltage, temperature, current, and state of charge to ensure safety and longevity.
Depth of Discharge (DoD)
The percentage of battery capacity that has been used. A higher DoD means more usable energy but may reduce battery lifespan.
State of Charge (SoC)
The current energy level of a battery expressed as a percentage of its total capacity.
Cycle Life
The number of complete charge/discharge cycles a battery can perform before its capacity degrades to a specified level (typically 80%).
Round-trip Efficiency
The percentage of energy that can be retrieved from a battery compared to what was stored, accounting for conversion losses.
C-Rate
The rate at which a battery charges or discharges relative to its capacity. A 1C rate means full charge/discharge in one hour.
Battery Degradation
The gradual loss of battery capacity and performance over time due to chemical aging and cycling.
Inverters & Power Conversion
Inverter
A device that converts DC (direct current) electricity from solar panels or batteries into AC (alternating current) electricity for use in homes and businesses.
Hybrid Inverter
An advanced inverter that manages power from solar panels, batteries, and the grid, enabling seamless switching between all three sources.
String Inverter
A type of inverter that connects a series (string) of solar panels, converting their combined DC output to AC power.
Microinverter
A small inverter attached to individual solar panels, optimizing performance panel-by-panel and reducing impact of shading.
MPPT (Maximum Power Point Tracking)
A technology in solar inverters that continuously adjusts operating conditions to extract maximum power from PV panels under varying conditions.
Grid-tied Inverter
An inverter designed to synchronize with and feed electricity into the utility grid, often with anti-islanding protection.
Off-grid Inverter
An inverter designed for standalone systems without grid connection, typically with battery charging capabilities.
Pure Sine Wave
A smooth, continuous AC waveform produced by high-quality inverters, suitable for all types of electrical equipment.
Modified Sine Wave
A stepped approximation of a sine wave, less expensive but may not work well with sensitive electronics.
Grid & System Types
On-grid System
A solar or energy system connected to the public electricity grid, allowing energy import/export and often with net metering.
Off-grid System
A solar or energy system that operates independently of the public electricity grid, relying on batteries for energy storage.
Hybrid System
A system that combines grid connection with battery storage, offering both grid benefits and backup power capability.
Grid-tied
Connected to the public electricity grid, allowing for energy import when needed and export when surplus is available.
Net Metering
A billing mechanism that credits solar energy system owners for the electricity they feed back to the grid, offsetting consumption costs.
Feed-in Tariff
A policy mechanism that pays renewable energy producers a fixed rate for the electricity they feed into the grid.
Microgrid
A localized group of electricity sources and loads that can disconnect from the traditional grid to operate autonomously during outages.
Virtual Power Plant (VPP)
A network of distributed energy resources (solar, batteries, generators) managed as a single power plant through software.
Islanding
When a distributed generation system continues to power a location even after grid power is lost, which can be dangerous for utility workers.
Anti-islanding Protection
Safety mechanism that automatically disconnects solar inverters from the grid during outages to protect utility workers.
Backup Power & Generators
Automatic Transfer Switch (ATS)
A device that automatically switches power supply from the grid to a generator or backup source within milliseconds during an outage.
Volvo Penta
A leading manufacturer of industrial and marine diesel generators, known for reliability, fuel efficiency, and performance in demanding conditions.
Diesel Generator
A backup power system using a diesel engine to generate electricity, common for industrial and commercial applications.
Generator Paralleling
Operating multiple generators together to increase total power capacity and provide redundancy.
Load Bank Testing
Testing a generator under artificial load to verify performance, identify issues, and prevent wet stacking.
UPS (Uninterruptible Power Supply)
A backup power system that provides instant electricity during outages using batteries, protecting sensitive equipment from power interruptions.
Blackout
A complete loss of power in a given area, often requiring backup generators or ESS for continuity of operations.
Brownout
A partial reduction in voltage or power availability, which can damage equipment without proper voltage regulation.
Load Shedding
Intentional shutdown of electric load to prevent complete failure of the power system during supply shortages.
Standby Power
Backup power systems that activate automatically when the primary power source fails.
Energy Management & Monitoring
Load Management
The process of controlling and optimizing the use of electrical loads to improve efficiency, reduce peak demand, and lower costs.
Peak Shaving
Using stored energy or reducing consumption during periods of high electricity demand to avoid peak pricing and reduce overall costs.
Demand Response
A strategy where consumers adjust their power usage in response to grid signals or price incentives, often automated through smart systems.
Energy Audit
A comprehensive assessment of energy use in a facility to identify opportunities for efficiency improvements and cost savings.
Smart Meter
An electronic device that records energy consumption in intervals and communicates with the utility for real-time monitoring and billing.
SCADA (Supervisory Control and Data Acquisition)
A system for remote monitoring and control of industrial processes, including energy management, generator systems, and solar farms.
IoT (Internet of Things)
A network of interconnected devices that collect and exchange data, enabling smart monitoring, automation, and optimization in energy systems.
EMS (Energy Management System)
Software and hardware that monitors, controls, and optimizes energy consumption and production in buildings or facilities.
Real-time Monitoring
Continuous tracking of system performance, energy production, and consumption with instant data updates and alerts.
Performance Analytics
Data analysis tools that evaluate system efficiency, identify issues, and provide insights for optimization.
Power Quality & Electrical Concepts
Power Factor
A measure of how effectively electrical power is being used, ranging from 0 to 1. Poor power factor increases energy costs and system losses.
Reactive Power
The portion of electricity that establishes and sustains electric and magnetic fields in AC equipment, measured in VARs (Volt-Amperes Reactive).
Active Power
The actual power consumed by electrical devices to perform useful work, measured in watts (W) or kilowatts (kW).
Apparent Power
The combination of active and reactive power, measured in volt-amperes (VA) or kilovolt-amperes (kVA).
Surge Protection
Devices or systems that protect electrical equipment from voltage spikes caused by lightning, grid switching, or other events.
Voltage Regulation
Maintaining stable voltage levels despite variations in load or supply, critical for equipment protection and system reliability.
Harmonic Distortion
Unwanted frequencies in electrical systems caused by non-linear loads, which can damage equipment and reduce efficiency.
Three-phase Power
A power distribution system using three alternating currents offset by 120 degrees, common in commercial and industrial applications.
Single-phase Power
A power system with one alternating current, typically used in residential applications.
System Performance & Economics
Capacity Factor
The ratio of actual energy produced by a system to its maximum possible output over a period, accounting for weather and downtime.
Performance Ratio
A quality factor measuring the actual yield of a solar system compared to its theoretical yield under ideal conditions.
Specific Yield
The annual energy output per installed kilowatt of solar capacity, measured in kWh/kWp, indicating system productivity.
Levelized Cost of Energy (LCOE)
The total cost of building and operating a power generation system divided by the total energy produced over its lifetime.
ROI (Return on Investment)
The financial return from a solar or energy system, calculated as net savings divided by total investment cost.
Payback Period
The time required for energy savings to equal the initial investment cost, typically 3-7 years for solar systems in Lebanon.
Degradation Rate
The annual percentage decrease in solar panel output, typically 0.5-0.8% per year for quality panels.
System Availability
The percentage of time a system is operational and producing energy, critical for commercial applications.
Uptime
The amount of time a system is functional and available, often expressed as a percentage (e.g., 99.9% uptime).
Installation & Components
Racking System
The structural framework that secures solar panels to rooftops or ground mounts, designed to withstand wind and weather.
Balance of System (BoS)
All components of a solar system except the panels themselves, including inverters, wiring, mounting, and electrical equipment.
DC (Direct Current)
Electrical current that flows in one direction, produced by solar panels and batteries.
AC (Alternating Current)
Electrical current that periodically reverses direction, used by household appliances and the power grid.
Combiner Box
An enclosure where multiple solar panel strings are combined before connecting to the inverter.
Charge Controller
A device that regulates the voltage and current from solar panels to batteries, preventing overcharging and deep discharge.
Junction Box
A weatherproof enclosure on the back of solar panels where electrical connections are made.
MC4 Connector
Industry-standard waterproof electrical connectors used for solar panel wiring.
Optimizers
DC-to-DC converters attached to individual panels to maximize energy harvest, similar to microinverters but at the DC level.
Regulations & Standards
IEC Standards
International Electrotechnical Commission standards for solar equipment quality, safety, and performance testing.
Tier 1 Manufacturer
Top-tier solar panel manufacturers with vertically integrated production, proven track records, and financial stability.
Warranty Coverage
Manufacturer guarantees for solar equipment, typically 25 years for panel performance and 10-15 years for inverters.
Product Warranty
Coverage against manufacturing defects, typically 10-12 years for solar panels.
Performance Warranty
Guarantee that solar panels will maintain minimum power output, typically 80-90% after 25 years.
Building Permit
Official approval required before installing solar systems, ensuring compliance with local codes and regulations.
Electrical Code Compliance
Adherence to national and local electrical safety standards for solar and energy system installations.
Advanced & Industry 4.0 Technologies
Industry 4.0
The fourth industrial revolution, integrating IoT, AI, data analytics, and automation into energy and manufacturing systems.
Machine Learning
AI technology that enables systems to learn from data patterns and make predictions, used for energy forecasting and optimization.
Predictive Maintenance
Using data analytics and AI to predict equipment failures before they occur, minimizing downtime and repair costs.
Digital Twin
A virtual replica of a physical energy system used for simulation, optimization, and predictive analysis.
Edge Computing
Processing data locally at or near the energy system rather than in the cloud, enabling faster response and reduced latency.
MQTT Protocol
A lightweight messaging protocol ideal for IoT devices in energy systems, enabling efficient real-time communication.
Time-series Database
Specialized databases like InfluxDB or TimescaleDB optimized for storing and analyzing time-stamped energy data.
Blockchain for Energy
Distributed ledger technology enabling peer-to-peer energy trading and transparent renewable energy certificate tracking.