With the slow charging rate of C/20, the battery SoC reaches up to 74% of the capacity; this stored energy supports the evening peak for an interval of about 4 hours at C/10
discharge rate. This is shown as voltage improvement in Fig. 7 and power import reduction from the feeder in Fig. 8. With the faster C/10 charging rate, the battery SoC reaches up to its set overcharging limit of 95% and more energy is available for evening support. If the discharge rate is set to a higher level at C/5, the energy depletes in a shorter time of about 3 hours, however, with a larger import reduction at the peak load (higher tariff period) as shown in Fig. 8. For the slower C/20 discharge rate, the support can be provided for a longer duration of about 6 hours, until the minimum SoC is reached. Although maybe not all of the period has the higher tariff at the peak load, a more intelligent control could be devised to ensure that the maximum economic benefit can be achieved by integrating the charging and discharging control strategy with the electricity tariff.