Technical Lexicon Photovoltaics & Battery Storage

12 key terms — explained by certified expert assessors

At a glance: This glossary explains key technical terms from photovoltaic and battery storage assessment practice. Each term is linked with standards references, practical examples, and scientific studies. Created by the expert assessors at Prosperus GmbH (PV-BESS-Assessor) with over 15 years of experience and 850+ assessed systems.

Battery Energy Storage (BESS)

Thermal Runaway

Uncontrolled exothermic chain reaction in Li-ion cells

 UL 9540A

Test standard for thermal runaway propagation

 IEC 62619

Safety standard for industrial Li-ion batteries

 VDE-AR-E 2510-50

German safety standard for stationary batteries

 State of Charge (SoC)

Current charge level of a battery in percent

 State of Health (SoH)

Battery health status compared to its initial condition

 Battery Management System (BMS)

Electronic control and monitoring system

Photovoltaics

PID Effect

Potential-induced degradation in solar modules

 Hotspots

Localized overheating of individual solar cells

 DC Arc Fault

Electrical arc in the PV DC circuit

 Electroluminescence (EL)

Imaging diagnostic method for solar modules

 IV Curve Measurement

Current-voltage characterization of solar modules