MSSL
Market Support Services Licensee - the default retail electricity tariff structure in Singapore, published by SP Group.
Market Support Services Licensee (MSSL) tariffs are the default retail electricity tariffs in Singapore, published quarterly by SP Group. Sites that have not switched to a contestable retail contract are billed under MSSL.
MSSL tariffs have a fixed peak-window structure with defined peak and off-peak pricing. This structure makes them highly optimisable for peak shaving and tariff optimisation - the price differentials between peak and off-peak are large enough to make dispatch worthwhile.
MSSL is the alternative to a Contestable retail contract, where the customer negotiates directly with a licensed retailer for a bespoke tariff. Larger customers (typically >2 GWh/year consumption) are eligible for Contestable retail; smaller customers are usually on MSSL by default.
In Singapore
SP Group publishes MSSL tariffs quarterly. Peak and off-peak windows are pre-defined and consistent, which makes them cleanly modellable for dispatch.