# String

A group of solar modules wired in series so their voltages add while the current stays that of a single module. The string is the basic building block a string inverter's MPPT channel connects to.

Source: https://inverterdata.com/en/glossary/string/
Site: InverterData (inverterdata.com) — open technical specification database
Last updated: 2026-08-24
License: free to quote with attribution to inverterdata.com

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Because the modules are in series, the whole string carries the same current, so the weakest module sets the pace: partial shade, soiling or a mismatched panel on one module drags down the entire string. That is the core argument for module-level electronics such as **power optimisers** and **microinverters**. String length is bounded at the top by **Voc** in cold conditions and at the bottom by the inverter's minimum **MPPT voltage** on hot days, and the usable window between those two limits is narrower than it first appears. Keep all modules in a string identical in model, orientation and tilt.