AP4 Energy
Field Services

AP4 Energy Services (formerly TC&E) is a premier field engineering service company specializing in Controls, Exciter, and LCI systems. Our OEM-trained field services engineers specialize in comprehensive field maintenance services and equipment upgrades on both GE aeroderivative and GE heavy-duty gas turbines. We strive to provide our customers with the highest quality field service engineers equipped with the appropriate skill set to support your controls service requests.


Large Frame Controls Services Upgrades

AP4 Energy Services specializes in controls and excitation systems on GE large frame gas and steam turbines. These services include a wide variety of controls maintenance, troubleshooting, and system upgrades. Our OEM-trained field engineers are here to ensure your equipment continues to operate reliably and efficiently.

Turbine System Upgrades

Power plant personnel look to AP4 Energy Services when they are seeking a trusted non-OEM service provider that can help develop and implement customized controls system projects. We are a trusted partner for many non-OEM equipment vendors throughout the industry.

Aerderivative Field Services

From basic troubleshooting to DLE Mapping and O&M contracts, AP4 Energy Services can meet all of your aeroderivative needs. Our expert team of DLE Mappers that are ready and able to provide the on-site support you require.



Using the latest technology, components, and lessons learned through decades of experience, AP4 Energy Services can ensure complete reliability for both start-up and continuous operation.


This is the key to success in today’s competitive power markets. Heat Rate, Capacity, Start-Up, and Maintenance Costs are critical to the success of aging power plants.


Spending good money where it makes the most difference! We understand that O&M budgets are shrinking, so we work with the plants to understand where and when to repair, replace, or upgrade for maximum return.


Aging systems can continue to provide reliable service for many years to come with the proper service, maintenance, and repairs. Push your upgrades out 5-10 years with confidence.