In early July 2026, Sungrow announced the commissioning of the Santong battery energy storage system in Terengganu — a 100 MW / 400 MWh project owned by Tenaga Nasional Berhad and described as Malaysia’s first grid-forming, grid-connected BESS (SolarQuarter). The system is reported to support both grid-following and grid-forming operating modes to strengthen the resilience of the national grid. A single project in one country is not, by itself, headline news for a power engineer. What it marks is: grid-forming has crossed from a specialist feature into a mainstream connection requirement, and that shift changes the studies a battery project must pass before it is allowed to connect.
Grid-following versus grid-forming, briefly
The distinction matters because it changes the machine’s behaviour during exactly the moments a network is most vulnerable. A grid-following inverter measures the grid voltage and injects current in synchronism with it. It needs a stable voltage reference to lock onto; it is, in effect, a follower. On a strong grid this is fine. On a weak grid, or during a disturbance when the reference itself is wobbling, a large fleet of grid-following inverters can struggle to hold synchronism and can even interact adversely with one another.
A grid-forming inverter behaves more like a voltage source. It establishes its own internal voltage phasor and holds it, so it can support the grid voltage and frequency rather than merely tracking them. It contributes to system strength instead of consuming it, and it can, in principle, help ride through and even help re-establish a network after a severe disturbance. That is why system operators are increasingly specifying grid-forming capability for large batteries: as synchronous generation retires, something has to provide the voltage-source behaviour the grid used to get for free from spinning machines.
Why this is a regional trend, not a one-off
Santong is a concrete instance of a movement already visible across SoftNitro’s markets. In Australia, AEMO has made grid-forming battery storage a priority and set out technical expectations that push new large batteries toward grid-forming capability, driven partly by the rising cost and scarcity of synchronous condensers (Energy-Storage.News). The same logic applies wherever inverter-based resources are displacing thermal plant — including the GCC’s fast-growing storage fleets and Pakistan’s evolving grid. The engineering driver is universal: falling system strength and falling inertia.
For developers, the practical consequence is that “we will use a grid-forming inverter” is a claim that now has to be demonstrated, not asserted. And demonstrating it is a study problem.
What grid-forming changes in the connection studies
A grid-following battery is typically assessed with RMS-domain models — load flow, balanced fault levels, and the standard grid-code checks. Grid-forming capability cannot be fully validated that way, because the behaviour that makes it valuable lives in the fast electromagnetic transient domain that RMS simulation smooths over.
Three areas move to the front:
System strength and short-circuit ratio. The reason grid-forming is being demanded at all is weak-grid connection. That means the grid integration study has to quantify the short-circuit ratio at the point of connection and confirm the inverter’s control mode is stable at the strength actually available — not the strength assumed at feasibility stage. A grid-forming claim is only meaningful against a defined system-strength envelope.
EMT studies, not just RMS. Validating grid-forming response to faults, phase jumps and weak-grid conditions generally requires electromagnetic transient (EMT) simulation with a proper inverter control model, because the control dynamics act on a timescale RMS tools do not resolve. This is the same reason system operators increasingly ask for EMT models of inverter-based plant. A project that only ran RMS studies has not demonstrated grid-forming behaviour; it has demonstrated steady-state adequacy.
Fault ride-through and stability contribution. Grid-forming plant is expected to stay connected and support the grid through disturbances. Proving that means stability analysis that exercises the plant against the credible fault set and confirms it rides through and contributes to recovery rather than tripping and making things worse. As inverter-based resources displace synchronous machines, their transient behaviour becomes the thing that determines whether the system holds together.
The dual-mode detail worth noting
Santong is reported to support both grid-following and grid-forming modes. That dual capability is common in current hardware, and it introduces a study nuance that is easy to miss: the plant’s fault and stability behaviour depends on which mode is active, and the settings within each mode. A connection assessment has to be explicit about the operating mode assumed and confirm the mode the operator will actually dispatch is the mode that was studied. Verifying a plant in grid-forming mode and running it in grid-following mode — or vice versa — is a mismatch between the study and reality of exactly the kind that undermines a connection case.
What affected parties should be planning for
For developers, the message is that grid-forming is becoming table stakes for large batteries, and the connection application now needs EMT-grade evidence, not a datasheet claim. Budget the study scope accordingly and secure a credible system-strength figure early, because it can change the whole design.
For utilities and system operators, the shift is an opportunity and an obligation: grid-forming storage can substitute for some of the strength and inertia that retiring plant removes, but only if connection standards specify the behaviour clearly and the connection studies verify it rigorously. Vague requirements produce vague compliance.
For industrial operators and IPPs weighing storage, the takeaway is that the inverter control mode is now a first-order engineering decision, not a procurement footnote — one that interacts directly with the strength of the grid they are connecting to.
Santong is one project, but it is a marker on a trend line that runs through every network moving from synchronous to inverter-based generation. The batteries are changing what they are asked to do, and the studies that let them connect have to change with them. For any developer or utility navigating a grid-forming connection, the engineering question is no longer whether the inverter can form the grid, but whether the studies prove it will do so on the grid it is actually joining. That is the work SoftNitro does through its power system studies practice.
