Construction has started on Pattern Energy’s planned repowering project at its 283MW Gulf Wind wind farm on the Gulf coast of Texas, where the US developer is replacing 118 Mitsubishi 2.4MW turbines with a like number of Siemens Gamesa 2.3MW units.

Though smaller by nameplate, the new machines at the facility south of Corpus Christi – Pattern Energy’s first when it came online in 2009 – will in fact have the potential to produce over 2.4MW each using the OEM’s Power Boost technology, meaning the plant’s topline capacity will remain at 283MW, Pattern Development project director Terrence Cantorna told Recharge.

“This repowering will increase production at the Gulf Wind facility. Each of the turbines at Gulf Wind is being replaced with a technically-advanced, more-efficient, and more productive turbine,” he said.

“The SWT2.3-108 rotor [at 108 metres in diameter] is larger than the Mitsubishi's [95-metre design] and the generator is capable of generator more power, up to 2.415MW, using the Power Boost functionality.

“The Siemens Gamesa [2.3MW model] is the best turbine candidate for the project because it optimises wind resource, while simultaneously maximising the existing infrastructure.”

Pattern Energy CEO Mike Garland added: “Repowering Gulf Wind with brand new turbines made strong economic sense due to its unique location on the Gulf coast, where the winds blow strongest at the times of Texas’ peak energy demand and pricing.

“[Wind turbine] technology has improved rapidly since it first began operating over a decade ago. By installing the latest technology turbines, we expect the repowered facility to have more efficient production, lower operating costs, renewed production tax credits and longer life, which combine to increase the long-term value of our fleet.”

Once in operation at Gulf Wind, the Siemens Gamesa SWT2.3-108 turbines, which fly 108-metre blades atop 80-metre towers, will generate enough annual energy to supply some 80,000 Texas homes.

Cantorna noted: “The 2.3-108 allows every turbine at the Gulf Wind project to be repowered. A incremental benefit ... is that the Power Boost functionality can be limited at each individual turbine, and that the overall wind farm capacity can be limited at the point of interconnection, to accommodate the existing electrical infrastructure and interconnection agreement.”

Siemens Gamesa’s onshore Americas CEO, José Antonio Miranda, said: “Repowering provides an opportunity to increase the efficiency, reliability and longevity of existing wind farms. We are excited to bring new life to the Gulf Wind facility.”

Gulf Wind – which weathered the destructive rigours of Hurricane Harvey when it struck the Lone Star state in 2017, returning to operation soon after the storm subsided – has entered into a new 20-year power purchase agreement with public utility Austin Energy for the majority of the wind farm’s energy production, with the remaining output being sold on to the grid at merchant power prices.

Pattern Energy, which operates 4.4GW of wind and solar projects in the US, Canada and Japan, in November was bought by Canada Pension Plan Investment Board, with plans to be taken private and united with sister company Pattern Development to create a new renewables group.