Demand response program in Singapore’s wholesale electricity market

•This paper provides an in-depth review of Singapore’s wholesale electricity market while highlighting the key constraints which are imposed by Singapore’s PSO. This review offers valuable references as Singapore’s electricity market is well-known for its reliability and maturity.•This paper investigates the newly introduced DR program, which is Singapore’s first initiative allowing consumers actively managing their loads, with an emphasis on the program’s salient features which are designed to smoothly introduce DR into the current regulated market. This study serves as a valuable and instructive example for the market deregulation practice, and particularly to those markets intending to take the first initiative to introduce demand response.•This paper includes the detailed mathematical formulations and various case studies to clearly explain the co-optimization of the market clearing process for both energy and ancillary services.