Germany, like many industrial countries, has been relying on coal and nuclear power to produce most of its electricity. But not for much longer.
The country is in the middle of an ambitious overhaul of its power supply system called Energiewende. When it’s finished in 2050, renewable energy sources like wind, solar and hydro will deliver 60 percent of Germany’s power.
Getting there without hiccups won’t be easy and some German towns have started getting ready. Bavaria's Rosenheim, for example, is using five GE gas engines manufactured across the border in Austria to generate 40 percent of electricity and 20 percent of heat for the town’s 61,000 people.
One of them is a massive J920 FleXtra engine, the largest and most efficient gas engine GE has ever built. The 20-cylinder, 10-megawatt machine is the size of a school bus. It is so powerful that it can supply base load power. That’s the minimum amount of electricity that must course through the grid to supply all customers connected to it. (Baseload is typically handled by large power plants.)
But it’s also nimble enough to ramp up to full power within 5 minutes - warp speed for utilities. It can help stabilize the grid when demand peaks and everyone wants power right now, like in the morning when people show up work.
That engine is now coming to the United States.
Power and speed are almost always a winning combination. Just ask any action hero. In the energy world it also helps utilities blend in uneven sources of energy like wind and solar. “Germany has very high targets for renewable power,” says Patrick Frigge, product line leader for 10 MW-class engines at GE’s new Distributed Power business. “But we’ve built an engine that can take care of base load as well renewables.”
What is distributed power? Remember when people started switching from landline telephones to cell phones? This is a similar idea. Distributed power technology, like the GE gas engines, allows customers to generate their own power near the point of use, rather than relying on a centralized grid. The concept is taking hold in the developing world, but also with industrial dynamos like Germany.
The J920 engine, which is manufactured in the picturesque Alpine town of Jenbach in Austria, converts nearly half of the energy from burning gas to electricity, and its combined power and thermal efficiency can reach a chart-topping 90 percent.
The engineers achieved this by developing a two-stage turbocharging system. The technology is similar to what Formula 1 cars use to boost efficiency and pickup (The J920 is not that different from a really big car engine, after all.) One benefit of the design is that the engine can work efficiently in higher altitudes where the air is thinner, like Denver or Mexico City. “This is the first blank-sheet-of-paper engine design that GE’s Jenbacher business has done in a long time,” Frigge says. “This is not a scaled up engine, this is not an improvement on an engine. This is the most efficient reciprocating engine in GE’s portfolio.”
The world’s first J920 FleXtra has been commercially operating in Rosenheim since 2013, and GE now has brought the engine to Houston’s Sky Global Partners LLC, who will use six of them to smooth out peaks in power demand in the U.S. (The American version generates power at 60 Hertz instead of the 50 Hertz generated by the European engine, but otherwise it is the same machine.)
Frigge says that the engine can be installed in clusters which can 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 everywhere people need heat and power and get maximum efficiency out of the fuel.”
The new gas engine has been working in Rosenheim for a year. Here’s how it blends renewables and gas power generation. Take a look: