The solar industry likes to distinguish between different categories of photovoltaics (PV). Home owners are associated with the rooftop PV sector, while the PV utility-scale sector is about measuring megawatts, mostly on wide, open fields. These have little to do with each other, apart from the use of solar technology.
Despite the market dominance of both of these categories, the success of the energy transition, which is driven by large shares of PV and other intermittent electricity sources, is dependent on a technology that stems from the – hitherto small-scale – off-grid PV sector: the grid-forming inverter.
Until the middle of the 2010s, these types of frequency converters were only used in off-grid microgrids. They are able to create a stand-alone power system through frequency and voltage creation and can perform black starts. A microgrid is a locally confined power grid made of generators (e.g. PV/wind), storage systems (battery energy storage systems (BESS)) and consumers. It can be operated parallel to the grid and continue to run as a stand-alone power system if required.
Grid-forming inverters make it to the grid
With the increase of renewable energy in the electricity system, grid-forming inverters – and thus grid-forming technology – have made it from microgrid applications to the public grids. Now they are taking care of basic functions through the delivery of system services for a stable grid, like the supply of power system inertia.
Renewable energy power plants and battery storage system based microgrids, which were made possible through grid forming inverters, also have evolved. While microgrids were originally used to generate up to a few hundred kilowatts (kW) for small settlements, today they secure the power supply of entire islands and towns and offer solutions to energy-intensive industries in remote regions, particularly the mining industry.
Below, we present two innovative applications of network-forming technology: One in the area of off-grid/microgrids, and the other in the area of grid-forming. Both technologies show off the enormous potential of grid-forming inverters in microgrids and for the public power grid.
On the west coast of Saudi Arabia, the Red Sea Project microgrid serves as a global benchmark for next-generation power supply. It is an industrial-scale, completely off-grid PV+BESS-microgrid. The plant combines around 400 megawatts (MW) of PV with around 1.3 gigawatt hours (GWh) of battery storage and is considered by Huawei and partners to be the largest PV+BESS-microgrid of its kind.
The goal is to supply the tourism infrastructure of the Red Sea Project with renewable energy 24/7, including the airport, hotels and supply systems. The technical implementation in this region is considered to be especially challenging due to high humidity and air salt content as well as temperatures up to 50°C.
Key technical features of the Red Sea microgrid:
Huawei reports that the microgrid has been operating smoothly for around two years and in this time has supplied more than 1 billion kilowatt hours (kWh) of green electricity. This scale of electricity production makes it clear that a system like this works in real-life operation over a long period of time – a decisive step in the transformation of grid-forming technology from the pilot phase to the megawatt level. Huawei adds that the system can ensure the power supply of up to 1 million people (or equivalent). This demonstrates how grid-forming inverter technology enables PV+BESS microgrids, which, just a few years ago, were only possible with typical power plant solutions.
In the UK, the application of grid-forming technology in the public power grid has outgrown the pilot status. In Phase 2 of the Stability Pathfinder tender for 2022, the British transmission system operator NESO specifically named plants with grid-forming inverters (e.g. BESS) as “fossil fuel-free power stations” for delivering system services. As a result, the Scottish BESS-power plant Kilmarnock was awarded the contract for 65 percent of the circa 6.8 gigavoltampere (GVA) of the total power system inertia.
The asset from battery storage developer Zenobē with a capacity of 300 MW/600MWh started operation in January 2026, reaching a second milestone for the UK: Blackhillock, also developed in Scotland by Zenobē, is the most prominent practical example of grid-forming technology in Europe. The battery power plant came into operation in March 2025 with 200 MW/400 megawatt hours (MWh) and is currently being expanded to 300MW/600 MWh. Blackhillock is exceptional as it is the first battery storage project providing system services in the UK with a comprehensive package of grid-stabilizing active and reactive power. The grid-forming inverters for both plants came from SMA.
Scotland can be considered a model region for the practical implementation of grid-forming technology in Europe. The massive expansion of wind energy, along with falling synchronous generation, has massively increased the demand for renewable stability solutions – especially as the region has limited connections to the load centers in the south due to transmission bottlenecks. Grid operators are reacting to this by providing system services from inverter-based plants, significantly accelerating the market ramp-up. The pipeline of large battery power plants is growing accordingly. Alongside Blackhillock, the 400 MW/800 MWh plant in Eccles is already under construction.
