Mobile Gas Turbines for Utility Substation Support

Typical reasons for substation support

Common cases include replacing capacity lost when a substation transformer fails, supporting a network during substation reconstruction, covering summer or winter peaks in a constrained area, and supplying a large new load before transmission reinforcement is finished. Each case has a different duration and duty, which affects the choice of unit and fuel.

Write down the expected duration, the hours of running per day and the load profile before selecting equipment. A peak-only duty of a few hours a day is very different from round-the-clock supply.

Choosing the site

The turbine trailers, control trailer, fuel equipment and transformer need a level, well-drained area with heavy vehicle access. Space inside the substation fence is ideal but often limited; an adjacent plot with a short cable route is the usual alternative. Check ground bearing capacity, drainage and access for fuel deliveries.

Noise and exhaust are important near homes. Run a quick noise assessment and position the units to direct exhaust and noise away from neighbours.

Connecting to the network

Mobile turbines usually generate at medium voltage, and a mobile step-up transformer raises the voltage to match the substation bus. The connection needs a suitable bay or a temporary switchgear arrangement, protection relays coordinated with the network, and metering. Our page on mobile step-up transformers covers the equipment.

Cable routes, terminations and earthing must be designed and tested like any permanent connection. The power cable guide sets out what to check.

Fuel supply

Natural gas is preferred where a suitable supply line is near the substation. A temporary connection, pressure regulation and metering may be needed. Where gas is not available, many mobile units can run on liquid fuel, which requires tanks, unloading and fuel treatment on site.

Plan fuel deliveries for the running hours expected, with a margin for extended operation. Road access and local rules for fuel storage near substations may limit tank size.

Protection and grid operation

Protection studies must check how the turbine behaves during network faults and how its relays coordinate with the substation’s protection. The grid operator will need to agree the operating mode, whether the unit follows a dispatch signal, holds a fixed output or controls voltage.

Control room staff should be trained on the temporary arrangement. Clear switching procedures avoid mistakes when connecting and disconnecting the unit.

Permits and timelines

Even temporary generation needs air permits or permit variations, and sometimes noise consent. Some jurisdictions have faster routes for emergency or temporary units; others treat them like permanent plant. Start the permit process as early as possible, in parallel with logistics. The emissions permit guide explains the typical steps.

Mobilisation time depends on unit availability, transport permits, site works and connection. A realistic plan covers each step, as shown in our mobilisation timeline guide.

Operating the unit

Mobile turbines need trained operators, routine inspections, water washing and filter changes like any gas turbine. For long deployments, agree who operates and maintains the unit, what availability is expected and how faults are reported. Remote monitoring lets the utility and the operator see the unit’s status in real time.

Keep critical spares close by. A unit that waits days for a part does not support the substation.

Working with the utility’s teams

Substation support brings together several utility teams: network planning, protection, control room operations, substation maintenance and community relations. Agree a single point of contact for the deployment, a clear division of responsibilities and a meeting rhythm during mobilisation and operation. Joint walk-downs of the site before connection catch many practical issues early.

Share the operating procedures, protection settings and test results with every team involved. When an unexpected event happens, people who already know the temporary arrangement make better decisions.

Plan the communications link between the turbine control trailer and the utility control room. Dispatch signals, status and alarms should reach the control room reliably, with a backup channel in case the primary link fails.

Finally, agree how performance will be reported. A short daily report of energy delivered, running hours, fuel used and any trips keeps everyone informed and builds the record needed if the utility wants to repeat the deployment elsewhere.

Planning the exit

Decide at the start what happens when the permanent fix arrives. The unit is disconnected, the site restored and the equipment moved to its next job, or in some cases the utility decides to keep it for peak support. Include decommissioning, cable removal and site restoration in the plan and budget.

Record lessons learned. Utilities that use mobile turbines repeatedly can prepare standard connection points and procedures at substations where support is likely to be needed again.