The electricity industry is categorized into contestable and non-contestable sectors. The structure of the Singapore electricity market is shown in the following figure.

The players in the contestable sector include:

The players in the non-contestable sector are:

The companies that operate in the non-contestable sector are natural monopolies.

As the Regulator and the Power System Operator, the Energy Market Authority (EMA) oversees the activities in both the contestable and non-contestable sectors to ensure a competitive, secure and reliable electricity supply to consumers.