How Can a Battery and Time‑of‑Use Save Rural Solar Grids?

Imagine a small Malaysian town where every house has a 100 kW solar panel. When the sun shines, energy is plentiful, but at night the grid voltage can drop, causing problems. Researchers tested two tricks: an energy storage battery (BESS) and shifting loads according to time‑of‑use (TOU) tariffs. Using real data from a 110‑node network, they simulated scenarios with 100 % solar penetration. Alone, neither the battery nor TOU could keep the voltage stable. But by combining them—a 0.4 MWh battery plus a 20 % load shift—the minimum voltage rose from 0.924 to 0.951 pu, eliminating violations. Active power losses also fell and grid dependence decreased. Even with 60 % PV, a 0.4 MWh battery and just 10 % TOU were enough to maintain stability. This hybrid approach is scalable and can help other rural areas integrate more solar power safely, showing that smart technology combos are key to a greener future.

The analysis was performed using DIgSILENT PowerFactory, a dynamic simulation software that models both electrical components and network management controls. The studied network includes eight distribution lines connected to two 132/11 kV, 15 MVA transformers, serving a total load of 20.006 MVA. Each node is equipped with a 100 kW photovoltaic system, allowing evaluation of penetrations from 0 % to 100 %. The model incorporates typical load curves of a Malaysian rural area, with consumption peaks in the morning and evening and a near‑zero nighttime minimum. The BESS was modeled with a 0.4 MWh capacity, 0.2 MW charge/discharge rate, and a rapid response curve, capable of intervening within a few simulation cycles. The TOU scheme shifts 20 % of the load from low‑demand night hours to high‑demand daytime hours, reducing reactive power flow and improving power factor. Sensitivity analysis showed that below 60 % PV penetration, the battery alone can keep voltage above 0.95 pu. Beyond this threshold, the synergistic interaction between BESS and TOU becomes crucial: the battery absorbs excess daytime energy, while TOU reduces nighttime demand peaks, thus preventing voltage dip. Results confirm that a hybrid strategy can cut active power losses by 5 % compared to the unmitigated case, enhancing overall grid efficiency. This approach is especially relevant for rural grids, where transport infrastructure is limited and renewable integration is often constrained by voltage limits. The research suggests that incentive policies for BESS adoption and flexible TOU tariffs could accelerate the transition toward more resilient and sustainable energy systems.