Complementarity is an important attribute among different renewable energy sources (RESs). A multi-renewable energy system (MRES) offers an alternative to aggregate diverse RESs and can ensure the best attributes of their mutual characteristics. However

few papers conduct convincing research into the complementary operation of a MRES. This paper investigates the complementarities in a MRES that contains wind

photovoltaic

run-off hydro

pumped storage power plants and incorporates complementarity into the optimal operation of a MRES. The complementarity is theoretically summarized and first classified into two categories: natural and synthetical. To effectively capture the uncertainty and complementarity of RESs

the time-dependent clustering simulation technique is employed to generate their joint-scenarios. An equivalent runoff hydropower plant index is proposed

based on which a novel complementary operation model

that considers volatility and self-sufficient adequacy

is established. Results are presented and compared in a case study

which demonstrate the validity and scalability of the proposed methodology

reveals the complementarities under multiple time-scales

and illustrates the significance of complementary operations.