When Woody Allen declares his love for New York City on a bench under the Queensboro Bridge in the movie Manhattan, another New York mainstay makes a quiet cameo. Looming in the morning dusk just across the East River is the Ravenswood Generating Station, New York’s largest power plant with enough capacity to energize a fifth of the Big Apple.
New Yorkers have been using power generated by Ravenswood’s machinery, which includes a massive GE gas turbine, to meet peak demand during sweltering summer weather for decades. But last year the plant’s owner, TransCanada Corp., decided that it was time to add brains to Ravenswood’s brawn. “We wanted to bring cleaner, more efficient power generation to the marketplace,” says John McWilliams, vice president of energy operations at TransCanada.
Rather than spending hundreds of millions on new equipment, TransCanada used GE’s latest software, control system and combustion hardware to upgrade the existing turbine. Workers connected sensors to software and replaced key turbine parts with new components made from advanced materials developed for GE jet engines. “We were basically able to plug-and-play the latest and greatest technology into our existing unit,” says McWilliams. “GE has helped us find ways to be quite competitive with our infrastructure for much, much less.”
McWilliams says that in the past, control systems regulated power plants by looking at a few discrete data points such as firing temperatures, discharge pressures, the ambient temperature and humidity. “It’s not the best, it’s not the worst, you are in an acceptable range of operations,” McWilliams says. But the new technology, which GE calls “FlexEfficiency Advantage Advanced Gas Path,” is constantly gathering and analyzing data critical to performance of the turbine. A multitude of sensors is checking gas flows, temperatures, pressures, humidity and other variables, and feeds it back into the control system. The system is using the data to fine-tune the turbine to make sure that it is always running at its optimal level. “It’s real time and it’s interactive,” says McWilliams. “As things are changing, the control system is responding and always optimizing the unit.”
McWilliams says that the upgrade gives TransCanada “the flexibility to actually make some decisions on what we want to optimize. We can optimize for fuel efficiency, we can optimize for output, we can optimize for reduction of environmental emissions, or we can balance and see improvements of all three.”
The GE software installed at Ravenswood reaches beyond a single plant. It connects to the industrial Internet, a digital network that links people, data and machines, and taps pools of data generated by the entire GE turbine fleet running the same software. “We have access to the global view of power generation,” says McWilliams. “It allows us to improve or at least benchmark our performance. For example, if a power station in Pittsburgh is having an issue, we are able to quickly assess and analyze whether we are facing the same risks and then make some decisions to eliminate the problem before it occurs.”
McWilliams is quick to point out that the information provides a global perspective that is not specific to any turbine. “I can’t look across the East River at another New York plant and see how they are operating,” he says. “It’s not specific to that plant, it’s specific to that technology. We have service agreements in place, so much of the information is already at GE’s fingertips because they are directly connected to the units and receive the data continuously.”
On the hardware side, GE has supplied Ravenswood with new turbine blades, shrouds, and nozzles using advanced materials like single-crystal alloys and coatings originally developed for jet engines. They allow TransCanada engineers to fire the turbine at hotter temperatures, which make combustion more fuel efficient and power generation more productive.
As a result of the upgrade, Ravenswood is using less fuel to produce the same amount of power, making electricity cheaper and, relatively speaking, cleaner. TransCanada says that the upgrade has increased output by 5 percent. That’s enough electricity to power 10,000 New York households. Says Adam Addesso, manager of engineering projects at Ravenswood: “These upgrades displace more expensive megawatts on the system. It’s a win for everybody, and those are rare.”