Operators and owners of pv plants are regularly confronted with the appropriate selection of o&m providers in order to assure seamless operation and optimal yields. Any negligence on maintenance will – sooner or later – lead to performance reductions, loss of revenues and a reduction in the long-term value of the pv plant. The relevant selection criteria and the differences between various o&m providers are discussed in detail in the current edition of „Sonne, Wind & Wärme“ which makes it an interesting read (in German).