A solar power optimizer is an electronic device connected to each PV module in an array that individually maximizes energy harvest from each panel before sending power to a central inverter.
Introduction
Power optimizers provide panel-level maximum power point tracking (MPPT), enabling optimum output regardless of shading or other mismatch losses between modules in a string.
This mitigates limitations of string inverters where underperformance of one panel impacts others on the same string. Power optimization boosts total energy generation.
For commercial and residential solar installations in the UK, power optimizers combined with central inverters offer a balance of efficiency, cost and reliability.
Key Benefits of Power Optimizers
Panel-Level MPPT
Power optimizers perform independent maximum power point tracking on each panel using advanced embedded controls. This optimizes output from individual modules in changing conditions.
Shading or soiling of any panel does not impact others as with traditional string inverters. More energy is harvested.
Enhanced Safety
Power optimizers reduce the high DC voltage running through long panel strings to module-level voltages. This enhances safety for installers, maintainers and firefighters.
The lower DC voltage also allows thinner and longer cable runs from the array to the inverter, reducing costs.
Monitoring and Analytics
Power optimizers provide panel-level monitoring and fault detection capabilities. This granular visibility aids troubleshooting and maintenance.
Performance data enables predictive modelling to estimate production impacts from shading or soiling before losses occur.
Flexible Design
With panel-level MPPT, string lengths and orientations can be optimized for available roof space rather than forced into equal lengths. Design flexibility is enhanced.
Module mismatches can be corrected remotely through the power optimizer network, reducing service calls.
Limitations and Considerations
- Power optimizers add an incremental cost per module, typically £25-£100, that impacts system pricing.
- Central inverters are still required. A single inverter failure affects the whole array despite the optimizers.
- Installation process is more complex with an optimizer mounted on each panel. Accessibility for maintenance may be affected.
- Reliability depends on consistent quality across thousands of optimizer units. Failure of one disables a panel.
Solar power optimizers provide a compelling technology solution for UK residential and commercial PV systems by maximizing array yields through panel-level MPPT. When combined with central inverters, they balance performance and cost across large rooftop installations. For sites with shading issues in particular, power optimizers can upgrade the business case for solar by reducing mismatch losses.
