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JUSTSOLAR — Solar Module Manufacturer

Solar Energy Glossary

67 technical terms explained — from TOPCon and HJT to MPPT and CBAM. Everything B2B solar buyers need to know.

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A

AC (Alternating Current)
Electricity that periodically reverses direction. Solar inverters convert DC from panels to AC for grid or home use.
ALMM (India)
Approved List of Models and Manufacturers — India's solar module whitelist for government-backed projects.
Albedo
Reflectivity of surfaces. Higher albedo (white gravel, snow) boosts bifacial panel energy gain.
Anti-Reflective Coating (AR)
Thin layer on module glass that reduces reflection, increasing energy capture by 2-3%.

B

Backsheet
Protective layer on the rear of monofacial modules. Bifacial modules use glass instead.
BESS (Battery Energy Storage System)
Battery system for storing solar energy, typically LiFePO4 chemistry for commercial applications.
Bifacial Module
Solar panel that generates electricity from both front and rear surfaces. 5-30% more energy than monofacial.
Bifaciality Factor
Ratio of rear-side efficiency to front-side. JUSTSOLAR TOPCon: 80%, HJT: 85%.
BIS (India)
Bureau of Indian Standards — mandatory certification for solar modules imported into India.
BOS (Balance of System)
All components except the modules: inverters, mounting, cables, combiners, disconnects.
Bypass Diode
Component that prevents power loss when cells are shaded. Typical modules have 3 bypass diodes.

C

CBAM
Carbon Border Adjustment Mechanism — EU policy requiring carbon price for imported goods. Affects solar modules from 2026.
CE Mark
European Conformity certification required for solar modules sold in EU/EEA markets.
CFR (C&F)
Cost and Freight — Incoterms where seller pays ocean freight to destination port, buyer arranges insurance.
CIF
Cost, Insurance and Freight — seller pays ocean freight + All Risk cargo insurance to destination port.
Cell Efficiency
Percentage of sunlight a solar cell converts to electricity. Modern N-type cells reach 25-27%.
Combiner Box
Electrical enclosure that combines multiple PV strings into larger circuits before the inverter.

D

DC (Direct Current)
Electricity flowing in one direction. Solar panels produce DC, which is then converted to AC by inverters.
Datasheet
Product specification document listing electrical, mechanical, and environmental parameters of a solar module.
Degradation
Gradual power loss over time. Modern modules: <1% year 1, <0.4%/year after that.

E

EL Testing (Electroluminescence)
Quality test using DC current to reveal micro-cracks and cell defects invisible to the naked eye. JUSTSOLAR performs 100% EL testing.
EPC (Engineering, Procurement, Construction)
Turnkey project delivery model where one company handles design, equipment supply, and installation.
EVA (Ethylene Vinyl Acetate)
Encapsulant material that protects solar cells inside the module laminate.

F

FOB (Free On Board)
Incoterms where seller delivers goods to vessel at named port; buyer handles ocean freight and insurance.
Flash Test
Factory test measuring actual power output under Standard Test Conditions. Every JUSTSOLAR module is flash tested.

G

G12 (210mm wafer)
Large-format silicon wafer enabling higher module power (up to 730W). Used in JUSTSOLAR 640W/730W modules.

H

Half-Cut Cells
Cells cut in half to reduce resistive losses and improve shading tolerance. Standard in modern modules.
HJT (Heterojunction)
Premium N-type cell technology with best-in-class temperature coefficient. JUSTSOLAR HJT 730W at -0.24%/°C.
Hot Spot
Localized overheating in shaded or damaged cells. Prevented by bypass diodes and quality manufacturing.

I

IEC 61215
International standard for crystalline silicon PV module design qualification. All JUSTSOLAR modules certified.
IEC 61730
International standard for PV module safety qualification.
INMETRO
Brazilian certification required for solar modules used in grid-connected installations in Brazil.
Inverter
Device that converts DC electricity from solar panels to AC for grid connection.
IP Rating
Ingress Protection — indicates dust/water resistance. IP67/IP68 is standard for solar equipment.
Irradiance
Solar power per unit area (W/m²). Standard Test Conditions use 1000 W/m².
IV Curve
Graph showing current vs voltage at different light levels. Used to characterize module performance.

L

LCOE (Levelized Cost of Energy)
Total project cost divided by total energy generated over lifetime. Key metric for project economics.
LID (Light Induced Degradation)
Initial power loss when modules are first exposed to sunlight. N-type modules have near-zero LID.
LiFePO4 (LFP)
Lithium Iron Phosphate battery chemistry — safest and longest-lasting for stationary storage. 6000+ cycles.

M

MC4 Connector
Standard DC connector for solar module interconnection. Waterproof, UV-resistant.
MCS
Microgeneration Certification Scheme — UK certification required for government incentive eligibility.
MOQ (Minimum Order Quantity)
Smallest order size accepted. JUSTSOLAR standard MOQ is 1 x 40HQ container (720 pcs 600W modules).
MPP (Maximum Power Point)
Operating point where solar panel produces maximum power. Tracked by inverter MPPT algorithm.
MPPT (Maximum Power Point Tracking)
Inverter algorithm that continuously adjusts operating voltage to maximize energy harvest.

N

N-Type Cell
Solar cell doped with negative charge carriers. Higher efficiency and lower degradation than P-type.
NOCT (Nominal Operating Cell Temperature)
Temperature cells reach at 800 W/m² and 20°C ambient. Typically 42-45°C.

P

PERC (Passivated Emitter Rear Cell)
P-type cell technology being phased out. TOPCon and HJT are its N-type successors.
PID (Potential Induced Degradation)
Voltage-stress degradation in humid environments. Modern modules have anti-PID design.
Pmax (Maximum Power)
Peak power rating in watts under Standard Test Conditions (STC). Example: 600W TOPCon.
PPA (Power Purchase Agreement)
Long-term contract where solar developer sells electricity to buyer at fixed price.
PV (Photovoltaic)
Technology that converts sunlight directly into electricity using semiconductor materials.
PVsyst
Industry-standard software for solar project energy yield simulation and financial modeling.

R

Rapid Shutdown
NEC 690.12 safety requirement for rooftop solar. Module-level electronics (microinverters) comply.

S

SCADA
Supervisory Control and Data Acquisition — monitoring system for utility-scale solar plants.
Self-Consumption
Using solar electricity on-site rather than feeding to grid. Maximizes value when electricity prices are high.
STC (Standard Test Conditions)
1000 W/m² irradiance, 25°C cell temperature, AM 1.5 spectrum. Baseline for Pmax rating.
String
Multiple solar panels connected in series. Inverter MPPT operates on string voltage/current.
Sustainability
Environmental, social, and governance practices. JUSTSOLAR manufactures with renewable energy in some facilities.

T

Temperature Coefficient
Power loss per °C above 25°C. Lower is better. TOPCon: -0.30%/°C, HJT: -0.24%/°C (best).
Tier-1
Bankable solar manufacturer status. Implies financial stability and quality for project financing.
TOPCon (Tunnel Oxide Passivated Contact)
Mainstream N-type cell technology. ~49% of 2026 global production. JUSTSOLAR TOPCon 600W/640W/730W.
TUV Rheinland
Leading independent testing organization for solar product certification. All JUSTSOLAR modules TUV certified.
Trade Assurance
Alibaba payment protection program. Protects buyers against quality or delivery issues.

U

UL
Underwriters Laboratories — US/Canada safety certification required for North American markets.
UN38.3
UN test for lithium battery transportation safety. Required for international battery shipping.

V

Voc (Open Circuit Voltage)
Maximum voltage of a module with no load connected. Used for string sizing calculations.

W

Wafer
Thin silicon slice that becomes a solar cell. Industry standard: 182mm (M10) or 210mm (G12).

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