Impact of Jurong Island's Utility-scale Battery Energy Storage System Deployment on Load Hours Loss and Required Reserve Margin

Mr Ng Shi Xuan asked the Minister for Energy, Trade and Industry (Energy and Industry) whether the Energy Market Authority has reviewed the utility-scale Battery Energy Storage System (BESS) deployment on Jurong Island and its impact on the Loss of Load Hours and Required Reserve Margin.

Dr Tan See Leng: The Loss of Load Hours (LOLH) and the Required Reserve Margin (RRM) are system reliability metrics considered by the Energy Market Authority (EMA) in its generation planning. Today, EMA adopts a planning standard of no more than three LOLH per year, factoring both planned and unplanned prolonged outages in generating capacity, such as emergency maintenance or repair. This is one of the most stringent and commonly adopted standards internationally and translates to a RRM of 27%, where installed capacity of generating units must be at least 27% above peak electricity demand. In the last five years, Singapore's actual reserve margin was around 35% to 49%, with zero LOLH.

Generating units, such as conventional power plants, count towards the RRM, as they have the capability to mitigate prolonged outages of generation capacity. However, the Jurong Island Battery Energy Storage System (BESS) does not count towards the RRM, due to its limited discharge duration of around one hour at its maximum power output of 200 megawatts. It is deployed to support grid stability over a shorter duration, by providing fast-response backup that can be activated within seconds when there is an unexpected loss of generation.

As BESS technologies and prices improve, EMA is evaluating the role of BESS in our power system. This includes how to incorporate BESS in future generation planning assumptions as well as studying whether enhancements to infrastructure processes and market frameworks are needed to better harness the benefits of BESS.