Grid-forming controls for energy storage
Grid following vs. grid forming
Lead the grid. Don't follow it.
Nearly every operating battery and solar inverter is grid following: it measures the grid and injects current in step with it. A grid-forming inverter behaves like a synchronous generator. It sets its own voltage and frequency, resists change instantly, and can run as the only source in an island.
Measures the grid, then reacts
Sets its own voltage and frequency
Why grid forming, why now
Spinning generation is retiring
Coal and gas units provide inertia and system strength by spinning. As they retire, frequency moves faster and grid-following plants struggle to stay connected when the grid needs them most.
Weak grids limit interconnection
The best renewable sites are often at the edge of the network, where low short-circuit strength makes grid-following plants unstable or forces curtailment. Grid forming lets plants connect and operate there.
Grid events are moving regulators
The 2025 Iberian blackout and India's 2026 Khavda disturbance put system stability at the top of the agenda. On Oʻahu, a grid-forming battery helped avoid rolling blackouts after large generator trips in 2024.
New revenue for stability
Great Britain's stability contracts, Germany's inertia market and Australia's system-strength contracts now pay grid-forming batteries for services that once came only from spinning machines.
Grid forming is going global
Required in seven markets. The EU is next.
In under two years, grid forming has moved from voluntary specifications to a hard requirement for new storage, and to a tender condition in four more markets. RfG 2.0 is set to apply it across all 27 EU member states.
| Market | Status | Requirement | Timing |
|---|---|---|---|
| MISO U.S. Midwest | Required | Grid-forming controls for standalone BESS in the interconnection queue | From the 2023 queue cycle |
| Finland Fingrid | Required | Grid-forming for grid storage of 10 MW or more | In force since Mar 2025 |
| Mexico | Required | Grid-connected storage must use grid-forming technology | Effective Apr 2026 |
| Germany | Required | New transmission-connected BESS; paid inertia market for GFM assets | 2026 |
| Portugal | Required | Transmission-connected or 45 MW and above: grid forming plus synthetic inertia | Connection requests from Oct 2026 |
| Chile | Required | All storage and the storage portion of hybrids; stable island operation | Entering operation from Aug 2026 |
| India CEA | Required | BESS of 50 MW or more: grid forming, black start and AGC | From Apr 2027 |
| ERCOT Texas | Grid support required | Advanced grid support (grid-forming-like) for inverter-based storage on the transmission grid; incentive proposed for existing plants | Interconnection agreements signed from Apr 2026 |
| Brazil · Hawaii · S. Korea · Saudi Arabia | In tenders | Grid forming specified in battery auctions, utility RFPs and procurements | 2019–2027 |
| European Union RfG 2.0 | Coming | Mandatory for storage of 1 MW or more across all member states | Adoption targeted Q4 2026 |
| Great Britain · Australia | Coming | Paid stability / system-strength contracts; mandates proposed | 2027+ |
Status as of November 2026. Summary of public information from grid operators and regulators; not legal advice.
Next wave: standards catch up
NERC already recommends grid forming for all new BESS on the bulk power system. IEEE is developing P2800.1, a recommended grid-forming practice, plus a grid-forming amendment to IEEE 2800, and DOE's UNIFI grid-forming specifications are now at Version 3.
Next wave: solar and wind
Fingrid now requires grid-forming support for new type D wind and solar connecting where the short-circuit ratio falls below 1.0, and India's draft rules would require grid forming for a share of new solar and wind inverters. The hybrid plant controller becomes central to compliance.
The PCS forms the grid. Fractal EMS makes it work.
Grid forming is primarily a function of the PCS: it creates the voltage waveform and delivers the instant response. But a plant is dozens of inverters, batteries, breakers, transformers and a point of interconnection that must act as one. As NERC puts it, grid-forming and black-start-capable are not the same thing. Grid forming is the prerequisite; the rest is plant design and controls, and that is where Fractal EMS comes in.
Fractal EMS
The plant brainGrid-forming PCS
Forms the gridBMS
Protects the cellsBlack start and islanding, sequenced
Eight steps from grid loss to grid return
When the grid is lost, the difference between a controlled island and a second outage is sequencing. Fractal EMS orchestrates every step.
Grid forming is not a checkbox on an inverter datasheet
It is a plant-wide behavior that has to be studied, sequenced, tested and operated. Fractal provides everything a grid-forming plant needs above the inverter, from the system studies to the equipment, the software and decades of service.
Future-proof for mandates
Meet ERCOT, MISO, Fingrid, CEA and upcoming EU requirements, and be ready for new stability markets.
Hardware-agnostic GFM integration
Proven with grid-forming PCS from multiple OEMs, including seamless GFM/GFL transitions.
Model-verified compliance
Inertia, droops and current limits modeled in PSSE, PSCAD and DIgSILENT, then tuned at commissioning.
Local control that keeps running
No cloud dependency: islanding, black start and resync execute even if the WAN is lost.
Revenue stacking in GFM mode
Keep virtual inertia while dispatching frequency response, voltage support and arbitrage.
Battery-aware protection
Live BMS limits, SOC clamps and fleet-wide SOC balancing protect batteries and warranties.
Utility, TSO and ISO integration
DNP3, IEC 61850, Modbus TCP, OPC UA and ICCP, with secure IPsec VPN.
Every grid event captured
A 50-samples-per-second historian for event analysis, model validation and warranty claims.
Grid forming in the field
Been there. Done that.
Grid forming matters most on weak grids. From transmission-connected plants and utility microgrids to isolated networks, off-grid industry and black start testing, Fractal EMS coordinates grid-forming events.
Transmission-scale BESS
Every PCS power module runs in grid-forming mode on a 110 kV network, contributing virtual inertia, voltage and frequency support and short-circuit current, while the plant still earns market revenue.
Community microgrid
When the village's single distribution line goes down, the battery islands and keeps the village powered for up to eight hours.
Off-grid industrial microgrid
The battery runs only in grid-forming mode as the backbone of an off-grid microgrid for a 450,000 sq. ft. facility, with fuel cells and solar.
Black start test bed
Ahead of a utility-scale deployment: black start, form a 34.5 kV island, energize test units in stages and resynchronize to the utility.
Isolated utility network
A standalone grid-forming battery works with the town's power station to support local solar and reduce reliance on diesel.
Remote solar-diesel network
A new solar farm and battery halve diesel use, saving about 150,000 litres a year; on sunny, low-load days the town runs on solar and battery.
One platform, every layer
One controls platform for every grid-forming plant
One stop shop
We design, supply, program, integrate and commission the whole scope, from grid-forming studies to black start testing, with a single point of accountability for the entire controls scope.
