Living up to their name, the Sunbelt states — stretching from Georgia to Arizona — are rapidly expanding solar capacity. Texas is currently at the forefront, though several other states are also accelerating growth. Over the past year, Mississippi increased its solar capacity by 73%, while Louisiana posted an even stronger rise of 90%, according to data from the Energy Information Administration.

Over the last decade, power grids have generally managed this surge in solar generation effectively. However, grids remain highly sensitive systems that require additional technical support as they handle increasing volumes of variable renewable energy. To preserve stability, engineers often integrate synchronous condensers — motor-generator systems that help maintain voltage levels and regulate power flows. Demand for such systems — widely deployed by GE Vernova in regions from the U.K. to Saudi Arabia — is growing globally due to their ability to provide grid inertia, short-circuit strength, and dynamic voltage support. Despite the name, inertia is exactly what modern grids need to remain stable.

Several years ago, GE Vernova began investigating alternative ways to address grid stability challenges using existing power generation assets. This effort led to an innovative breakthrough: its 7F series gas turbines can be enhanced to operate with synchronous condenser functionality while still retaining their standard power generation capabilities. Last year, the company partnered with a utility in the southern United States to implement a first-of-its-kind project that combines these two functions in real-world operation.

“This is something entirely new,” said Louis Veltre, product manager for 7F gas turbines at GE Vernova’s Gas Power division. “While similar capabilities exist for smaller aeroderivative turbines, this is the first time it has been applied to a full-scale heavy-duty gas turbine. We see strong potential here.” Given the widespread global deployment of these turbines, this innovation could unlock significant cost efficiencies while supporting continued renewable energy expansion.

Transforming Turbines into Multi-Functional Assets

According to Veltre, this enhancement becomes particularly valuable during peak solar production hours, when gas turbines would otherwise remain idle. “These turbines are connected to large generators capable of supporting grid stability,” he explained. “But when solar output is high, they typically sit unused, waiting to be dispatched solely for electricity generation. That means we already have powerful assets in place that can do more.”

During the project, engineers evaluated three potential approaches. Two options involved installing a mechanical clutch, but both proved either too costly or too complex. Ultimately, the team selected a clutchless solution previously developed by GE Vernova. “The six-month study was highly collaborative,” Veltre noted. “We assessed risks, mitigation strategies, and overall costs. In the end, all parties agreed that the clutchless approach offered the best balance.” The solution was successfully tested on a single 7F.05 turbine, establishing a proof of concept that could be replicated at other similar sites.

Renato Yabiku, product manager for synchronous condensers at GE Vernova’s Power Conversion and Storage division, emphasized the importance of maximizing existing infrastructure: “When you already have such a valuable asset, the goal is to optimize its use across varying operating conditions throughout the day.”

A Natural Synergy

This upgraded capability fits particularly well in Sunbelt regions, where solar generation peaks around midday — often exceeding what the grid can absorb. As a result, excess energy must be curtailed, meaning some of the generated electricity is effectively wasted.

Curtailment occurs for multiple reasons, Yabiku explained. In some situations, supply simply exceeds demand. In others, the grid lacks sufficient short-circuit strength, reactive power support, or inertia, limiting its ability to distribute available electricity. In such cases, adding synchronous condenser functionality — especially if located at critical grid nodes — can help reduce these losses.

The inability to fully utilize low-carbon electricity negatively impacts both solar project economics and environmental goals. However, Veltre pointed out that this new approach introduces an elegant solution: in the future, surplus solar energy could be used to power these modified turbines.

GE Vernova’s 7F.05 heavy-duty gas turbine is capable of operating in synchronous condenser mode, delivering voltage control, reactive power, and system inertia without consuming fuel. It can support renewable energy integration by utilizing surplus solar or wind power to stabilize the grid. (Image credit: GE Vernova)

When operating in standard turbine mode, 7F units burn natural gas. In synchronous condenser mode, however, they require electricity instead of fuel. In this configuration, the turbines shift roles — managing reactive power within the grid — and operate without combustion, relying solely on electrical input.

According to Veltre, this creates a highly efficient cycle: the grid requires stabilization precisely when excess solar energy is available, and that same surplus energy can be used to power the synchronous condenser function. In high-renewable systems, gas turbines are typically used to ensure stability through generation. By switching operating modes, they unlock an additional grid-support function that enhances overall system performance.

“This approach can also significantly reduce carbon emissions,” Veltre added. “Instead of burning fuel for voltage support, solar energy can be used to drive the generator and rotate the turbine, while simultaneously managing reactive power.” He noted that regions with high renewable penetration — such as California, Australia, the Middle East, and parts of Europe — are strong candidates for adopting this technology.

Source