Image: ZenobeElectricity grids have historically relied on the inertia of heavy spinning turbines in coal, gas, nuclear, and hydro plants to maintain frequency stability. But as we replace synchronous generators with solar and wind, that inertia disappears. Without action, a grid dominated by renewables risks becoming unstable.
Initial UK studies from 2012 showed that if non‑synchronous generation exceeds about 65% of total running capacity, the transmission system could not be secured against credible faults. That threshold is now being approached – and exceeded – in many leading markets. The solution? Grid‑forming inverters.
At Sunlink (Xiamen), we see grid‑forming technology as a game‑changer for high‑penetration solar and storage. It turns a battery or solar‑plus‑storage plant from a passive follower into an active grid‑shaping asset – providing synthetic inertia, voltage support, and even black‑start capability.
Grid‑Forming vs. Grid‑Following: What’s the Difference?
Grid‑following inverters track the grid’s voltage phase and frequency to synchronise and inject power. They are simple and work well when the grid is strong, but they cannot “see” or correct disturbances on their own.
Grid‑forming inverters use internal control algorithms to set their own voltage – often by emulating the behaviour of a spinning generator (a “virtual synchronous machine”). They can create their own reference signal, respond instantly to frequency deviations, and provide fault current.
Real‑World Proof: Blackhillock BESS (Scotland)
In northeast Scotland – once Europe’s oil capital – the 200 MW/400 MWh Blackhillock BESS, developed by Zenobe and using Wärtsilä equipment with SMA grid‑forming inverters, was commissioned in early 2025. It is the world’s first battery to provide full active and reactive power services to a transmission system.
The project supplies Great Britain’s grid with:
370 megawatt‑seconds (MWs) of synthetic inertia
116 megavolt amps (MVA) of short‑circuit level contribution
It passed the system operator’s Stability Pathfinder 2 procurement and now provides stabilisation services, stabilising voltage dips and phase jumps. According to Aaron Gerdemann of SMA, the hardware cost difference between grid‑forming and grid‑following is small – but the control complexity and design engineering are many times higher.
Global Momentum: From Australia to Saudi Arabia
Australia is one of the most mature markets. ARENA (Australian Renewable Energy Agency) has been funding grid‑forming projects since 2017, starting with the Dalrymple BESS (30 MW/8 MWh) that islanded a wind farm. Since then, ARENA has supported retrofits (Hornsdale BESS with Tesla’s virtual machine mode) and now has a $100 million program for advanced inverters. Nearly 100% of new front‑of‑meter BESS in Australia could be grid‑forming by 2030.
Saudi Arabia and Chile represent newer, fast‑growing markets. A three‑site, 7.8 GWh project in Saudi Arabia uses Sungrow’s grid‑forming Power Titan 3.0 platform. Sungrow has also conducted live transmission‑connected tests in Tibet and held a European launch in Madrid.
China is also moving: Huawei launched its grid‑forming FusionSolar 9.0 platform; Hithium partnered with Schoenergie for a 55 MWh project in Germany; CATL includes high‑voltage grid‑forming storage in its off‑grid industrial park in Shandong.
Why This Matters for Solar and Storage Developers
Grid‑forming inverters deliver four critical capabilities:
Synthetic inertia – Instantaneous response to frequency deviations, mimicking spinning mass.
Short‑circuit level (SCL) – Fault current to quickly damp disturbances (a 100 MW coal plant might provide 500 MVA; an equivalent wind farm only 100 MVA – grid‑forming inverters close that gap).
Black start – Ability to establish a stable frequency to restore power after a blackout.
Island mode – Operate off‑grid with stable voltage and frequency.
For a solar‑plus‑storage plant, adding grid‑forming capability turns it from a passive energy source into a grid‑enabling asset that can earn additional revenue from stability services – not just energy arbitrage or capacity.
Challenges Remain – But They Are Solvable
Grid codes worldwide are still catching up. Only a few TSOs (e.g., Great Britain’s Grid Code 0137, Germany’s new inertia procurement from January 2026) have codified grid‑forming requirements. Each market has different standards, which complicates product development.
SMA and Sungrow both emphasise that rigorous in‑house testing, hardware‑in‑loop validation, and close TSO collaboration are essential. The real test comes when the system is connected online – simulations are not enough.
There is also debate about whether every BESS should be grid‑forming. Many experts (including SMA) argue that only key anchor sites on the network need full grid‑forming capability, supported by a stability market incentive.
Sunlink’s Perspective: Preparing for the Grid‑Forming Future
At Sunlink, we are closely watching grid‑forming technology because it directly affects the bankability and performance of large‑scale solar and storage projects – especially in markets with high renewable penetration.
For developers and EPCs: When procuring inverters for BESS or hybrid solar‑storage plants, ask for grid‑forming capability even if local grid codes do not yet require it. Future‑proof your asset. Work with suppliers that offer full engineering support – modelling, tuning, and TSO liaison – not just hardware.
For asset owners: Grid‑forming inverters open new revenue streams: synthetic inertia, fast frequency response, and stability services. In markets like Australia and the UK, these services are already monetised. As more TSOs follow, early movers will capture higher value.
For policymakers and TSOs: Standardise grid‑forming requirements across regions. Create stability markets that reward synthetic inertia and system strength. Without clear rules, investment in resilience will lag.
Conclusion
Grid‑forming technology has moved from research labs to operational, transmission‑connected projects. Blackhillock, Dalrymple, Hornsdale, and large‑scale deployments in Saudi Arabia and China prove that inverters can replace synchronous generators for grid stability.
The search for system resilience is no longer theoretical. As solar and wind continue to grow, grid‑forming BESS will become the backbone of a stable, decarbonised grid. At Sunlink, we are committed to delivering solar and storage solutions that are not just clean – but also grid‑ready for the future.
Ready to integrate grid‑forming storage into your renewable project? Contact Sunlink to explore our PV‑storage packages and technical advisory services.