PV offset box

The PID box is a mitigation option for Potential Induced Degradation (PID). PID usually shows up after commissioning and can cut a string's performance by 20-80%. An IEA risk study costed the PID box as one mitigation scenario, used alone or together with partial repowering of the plant. In that cost comparison, doing nothing cost 15 k€ and the PID box scenario cost 238 k€. Adding partial repowering raised the cost to 3233 k€. In the related case study of a 10 MWp plant hit by PID, profit after 20 years fell 48% below expectations. With mitigation measures, and after counting their cost, the shortfall was held to 5% to 6%. A related preventive step is to put modules in strings that are not sensitive to PID. This means grounding one terminal through a transformer inverter or using an inverter with anti-PID features. Early-stage PID can be recovered, for example by applying a reverse voltage. More advanced PID cannot be fully recovered, so act early.

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• sentence 1: support check: partial - The PID box appears as a costed mitigation scenario and the 20-80% reduction/commissioning claim is stated, but 'up to 20-80%' is an upper bound and the passages don't tie the PID box to PID mitigation in prose.
• sentence 2: support check: partial - The table shows PID Box alone and with partial repowering as scenarios, but the passages don't identify the source as an IEA risk study. -->