Europe’s beating industrial heart, Germany, will lose as much as fifth of its lifeblood electricity over the next decade as the country pulls the plug on nuclear reactors. A process called Energiewende will replace nuclear power with a combination of electricity from natural gas and renewables.
The idea is simple, but not the execution. Nuclear plants feed the electrical grid with crucial “base load power,” the minimum amount of electricity that must flow through the grid for the country to run. Unlike wind or solar electricity, which ebb and flow with the whims of the weather, base load power must remain reliable and always on. “Germany has to make up for all that base load power generation,” says Scott Nolen, product line leader for power generating gas engines at GE Power & Water. “The country also has very high targets for renewable power. But we’ve built a new engine that can take care of both.”
Nolen is talking about a new J920 FleXtra gas engine from GE’s Jenbacher line. It is the largest and most-efficient engine GE has ever built. At 9.5 megawatts, the engine, which is part of GE’s ecomagination portfolio, generates more than twice as much power as other GE Jenbacher gas engines. It converts nearly half of the energy from burning gas to electricity (48.7 percent), another company record, and can supply customers with heat and hot water. The engine’s combined power and thermal efficiency can reach as high as 90 percent.
Nolen says that the new engine is “a great power generation innovation” because it can start up and shut down quickly, and allow utilities to meet the challenges that renewables, with their power fluctuations, impose on the grid. (Energiewende set renewable energy targets at whopping 60 percent of Germany’s total electricity needs by 2050.) “Let me tell you, living in Germany, the sun isn’t out all the time,” Nolen says. “With this engine, you can really have that flexibility, to be able to start up, meet the demand and then shut down quickly without wasting a lot of fuel when the sun does come out.”
Nolen says that clusters of the new engines could generate over 100 megawatts of power and still retain their high efficiency. “This is why distributed power is so attractive,” he says. “You have the capability to supply the engines all over the place where people need heat and power and get maximum efficiency out of every precious hydrocarbon molecule you have to burn.”
In Europe, the new engine will sit at the core of a municipal power plant in the Bavarian town of Rosenheim, population 61,000. The engine, in combination with four smaller Jenbacher engines and a waste incineration plant, will supply Rosenheim burghers and businesses with 40 percent of their electricity needs and a fifth of their heat. “The energy transition plant Energiewende can be achieved only if there is a cooperative effort, including contributions by municipal providers,” says Marcel Huber, Bavarian minister of state for environment and health.
But the engine has applications around the world. GE engineers designed a special two-stage turbocharger for the engine, similar to what you might find in Formula 1 race cars. It uses exhaust gas to compress the air flowing inside the engine and achieve the maximum power. One benefit of the design is that the engine can work efficiently in higher altitudes where the air is thinner, like in Mexico City. “A gas engine in Mexico City would be able to put out close to 90 percent of its rated power,” Nolen says.
Besides locations like Mexico, where it can be used to “firm up” the grid when base load starts to sag, the engine will have applications in Asia and sub-Saharan Africa, where even people in cities often lack power. “They can use these engines in a distributed fashion to supply the grid, or operate in an island mode when there’s no grid.”
From Energiewende to energy for the world, the new engine will help keep the power on.