Richard Wolf, President & CEO of Relevant Power Solutions, discusses this new startup venture and the launch of a new 45 MW mobile gas turbine generator product.

Tell us about the formation of Relevant Power Solutions.

Relevant Power Solutions is a privately owned startup with its two shareholders being S&W Energy Solutions and Luther King Capital Management. S&W Energy Solutions began working with Rolls Royce gas turbines during 2012 to provide support and technical assistance for the Trent gas turbine generator set program. After Siemens acquired the industrial gas turbine business of Rolls Royce, S&W expanded its role by providing balance of plant (BOP) equipment for Trent projects worldwide. In 2017, Relevant Power Solutions was formed to further expand the collaborative arrangement between Siemens and S&W Energy.

How does the arrangement work with Siemens?

Siemens wanted a large mobile gas turbine generator in its product lineup. The SGT-A45 was developed for this purpose. To build the SGT-A45 gensets, Siemens manufactures the gas generator and power turbine hardware in Montreal. The GT is shipped to Relevant Power Solutions in Houston for trailer mounting, package assembly and genset testing prior to shipment. Relevant Power Solutions also provides balance of plant solutions for Siemens’ gas turbine business on a project basis.

What can you tell us about the SGT-A45?

The industrial Trent 800 gas generator is a two-shaft gas generator that Siemens uses for the land-based SGT A65 genset rated at 65 MW. However, the weight of a 65 MW trailer mounted genset exceeds the practical limits of highway transportation. We calculated the practical upper limit to be 45 MW. Siemens engineers figured out that by removing the booster compressor from the Trent 800, the air flow through the gas turbine would be just right for a 45 MW product. This was a match for the existing RB211 power turbine, which was already developed and utilized for power generation and marine service. The entire flow path of blades, vanes and combustors is identical to the ongoing production line with no prototype hardware.

What is the ISO rating of the SGT-A45?

At an ambient temperature of 15°C and sea level elevation, the SGT-A45 is rated at 44.0 MW at the generator terminals with 40.4 % conversion of fuel input (LHV) to 60Hz electricity. For 50Hz applications, the rated output is 41.0 MWe with 39.0% efficiency. The gas turbine is physically identical for 50Hz and 60Hz applications. In addition, all the motors, controls and instruments on the package are dual-rated for 60Hz and 50Hz. To change the product from 50 Hz to 60 Hz or vice versa is a simple software toggle. Tell us about the electric generator. The gas turbine drives the electric generator directly with no gearbox. It is the same generator for 50Hz or 60Hz projects. It’s a two-pole utility grade air cooled design with brushless excitation. The generator air filter is set directly atop the generator compartment.

How do you plan to differentiate your product?

The SGT-A45 has a much smaller footprint per MW and a lower fuel consumption rate. Power output and fuel efficiency do not fall off at high ambient conditions (mobile gensets are often delivered to job sites with hot ambient temperatures). Water is generally not available for evaporative cooling, so the electricity that you produce is what the GT can deliver with no boost from external cooling. Even though all units will be capable of operating on natural gas fuel or diesel fuel, most project are forced to run on expensive diesel because natural gas is rarely available in remote areas. In short, fuel efficiency matters when you are operating base load, simple cycle on liquid fuel.

What are its service intervals?

The service interval for the SGT-A45 will be extended to 25,000 hours for liquid or natural gas fuel. This is possible as the gas generator is operating at less than the 65 MW capability of a Trent 800. Reduced firing temperatures associated with its 44 MW output will mean longer hot section life. The lower firing temperatures also allow the SGT-A45 to avoid a four-hour “restart lockout” often associated with other mobile gas turbine gensets. If the grid goes black and forces the GT to be taken off line, the SGT-A45 can restarted as soon as the grid is re-stabilized.

What is your go-to-market plan?

For those that want to purchase the SGTA45 mobile genset, contracting will be handled by Siemens. If leasing is desired, Relevant Power Solutions with be involved. For practical purposes, a one-year lease term is the minimum for a mobile genset of this size. When will it to go into service? The first SGT-A45 is on the test stand. We will load test every unit before shipment. The product is designed to fit into an air cargo carrier for rapid deployment. Genset #2 is in the advanced stages of manufacturing and packaging.