The city found the answer it was seeking in reciprocating engines. Drawing on the same technology used in the internal combustion engines found in automobiles, these efficient engines can be brought online and ramped up to produce precisely the amount of power needed on only a few moments’ notice. A newer, turbocharged version of the engines replaces the diesel fuel formerly needed to operate the engines with cleaner-burning natural gas.

In September 2016, Denton Municipal Electric contracted our team to provide comprehensive engineer-procureconstruct (EPC) services for a new 225-MW reciprocating engine plant. Permitting and design of the grassroots, $225 million plant began immediately so that our construction team could begin site work two months later. The aggressive timetable, made possible by our integrated EPC approach and the self-performance capabilities of our wholly owned subsidiary, AZCO, was necessary to meet the established project completion date of July 2018 — in time to meet peak summer demand.

To reach Denton’s renewable energy goals without subjecting ratepayers to increased rates, the design allows the plant to reach 20 percent power in two minutes and full plant output in less than five minutes. This aggressive design includes 12 Wärtsilä 18V50SG reciprocating engine generators configured to provide flexible, faststart power. The “plug and play” design makes it possible for each engine to be dispatched independently to scale output up or down during fluctuations in demand — all with minimal sacrifice in peak efficiency. The plant also has black start capabilities, enabling Denton Municipal Electric to bring the plant back online quickly following a widespread outage and without drawing power from the grid.

The Denton Energy Center is among the largest and most flexible reciprocating engine plants in the country. Due to its use of selective catalytic reduction to minimize pollutants, the plant is designed as one of the industry’s cleanest natural gas-fired — earning the 2018 Award of Merit in the Energy/Industrial category by Engineering News-Record Texas & Louisiana.