Solar PV · Glossary
Optimiser
A DC-DC device fitted behind each solar panel to perform per-panel MPPT before sending power to a central string inverter.
An optimiser (sometimes called a power optimiser or DC optimiser) sits behind each panel and performs the MPPT function locally, before the DC string returns to a central inverter. The dominant brand is SolarEdge, whose architecture requires optimisers as integral parts of the system. Tigo offers optimisers as retrofit add-ons to most third-party string inverters.
Optimisers solve the same shading problem as microinverters but at lower cost. They also enable rapid shutdown (panel voltage drops to 1V if the inverter is disconnected, useful for firefighter safety) and panel-level monitoring.
For most CCS installs in Cornwall, we deploy optimisers selectively: SolarEdge Genesis on shaded or complex-roof projects, plain Fox ESS or GivEnergy strings on simple south-facing roofs. See our solar installation page for system architecture options.