Innovation
The Way Forward: How GE Engineers Are Helping Build A Path To A Renewable Future
In the five decades since the first Earth Day, the world has made much progress in understanding the perils posed by climate change and finding the solutions we need. But we are far from done. The switch to electric cars alone will force us to reimagine not only how we make electricity, but also how we distribute it.
Renewables are clearly a big part of the future of energy, but so are natural gas, energy storage, hydropower and the digital grid. Other industries, like aviation, must also decarbonize to help prevent the planet from warming.
How should we get to the low-carbon future? Scientists at GE Research have some ideas. One team, for example, is building a superconducting generator for wind turbines to boost their efficiency and help lower energy costs. Another group of researchers at LM Wind Power, a subsidiary of GE Renewable Energy, is using 3D-printing technology to make lighter and stronger turbine blade tips, while also seeking in the future to make those same blades fully recyclable at the end of their lifespan. Their colleagues also are 3D-printing parts of wind turbine towers. Elsewhere, GE scientists are using powerful supercomputers to improve wind farm design and take gas turbines to the next level. Take a look.
A discovery made in the coldest cold more than a century ago is heating up GE’s wind turbine research. In 1911, Dutch physicist Heike Kamerlingh Onnes found that electrons, which usually lose energy as they careen around an electrical conductor, met no resistance in a mercury wire cooled to near absolute zero — the lowest possible temperature, minus 459.67 degrees Fahrenheit. That phenomenon, known as superconductivity, can help computer chips run faster and it enabled magnetic resonance imaging (MRI), among other things. Now superconductivity may be paving the way to more efficient generators for powerful offshore wind turbines.
How cool is this: Backed by a $20.3 million contract from the Department of Energy, GE researchers are looking for ways superconducting generators can help lower wind energy costs, simplify the turbine manufacturing supply chain and support the DOE’s goal of nearly tripling wind power’s share of U.S. energy production to 20% over the next decade.
In terms of fuel efficiency, commercial aviation has come a long way: The amount of fuel used per passenger has dropped 80% since 1960. Still, those savings have been offset by the skyrocketing growth of passenger aviation in the same period, leading aircraft and engine designers to search for new ways to reduce aviation’s impact on the environment in the decades to come. “We need something fundamentally different to take the next leap,” said John Yagielski, senior principal engineer at GE’s Global Research Center in Niskayuna, New York. Yagielski and his colleagues are at work on that fundamentally different something: an electrically driven propulsion system powerful and light enough to keep aloft a 175,000-pound commercial airliner and its 175 passengers.
2050 vision: That goal is being backed up by $4.8 million in new research grants from the U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) — and it will be no small feat. The challenge is figuring out how to convert a cleaner-burning biofuel into megawatts of electricity, and then how to turn that electrical energy into enough thrust to fly a Boeing 737-class jet. But that challenge is also an invitation for the GE engineers to reimagine what an aircraft engine looks like, drawing up new designs that might be more efficient for flight than the traditional model of engines beneath each wing. “It’s about proving the feasibility of a number of these technologies and convincing ARPA-E to invest in building a complete prototype and testing it,” Yagielski said. “This is for aircraft in the 2050s.”
If you regularly drive long distances, it’s a good idea to pop your car’s hood every few months for a thorough inspection. But if you’re only running to the supermarket once a week, you may be able to take a rain check on that quarterly checkup. That’s the approach engineers at GE Renewable Energy are now using to service wind turbines. They are calling it “odometer maintenance,” and it could mean more money in the bank for the wind farm operator and more renewables online for everyone else. “You don’t necessarily need to change your car’s oil if it’s been sitting in the driveway for months,” says Brian Theilemann, global services continuous improvement leader at GE Renewable Energy. “It’s the same with a wind turbine. We’re shifting away from a time-based approach to maintenance, to a usage-based approach.”
Time shift: Theilemann and his team are using software that ingests mountains of hard data about power output, wind speed, internal and external temperatures, bearing usage and even the type of oil used to lubricate a turbine’s gearbox. The software’s statistical model then delivers insights that help them determine the favored time for maintenance, which can extend the time a turbine stays online during the windy season. In fact, power producers can leverage odometer maintenance to schedule a fleet checkup during the less windy months of the year, which are less lucrative in terms of wholesale power revenues.
The wind industry is quickly growing up and so are wind turbines. That’s because they can generate more energy by reaching higher where the winds are stronger. In fact, by raising the height of existing turbines, it’s estimated wind farm operators could increase their output by up to 30%. Building taller turbines hasn’t been easy. They can be hard to transport and expensive to install — but every challenge can also be an opportunity. GE Renewable Energy, together with two innovative European companies, is aiming to 3D-print a solution.
Concrete gains: GE teamed up with LafargeHolcim, a global leader in building materials, and COBOD, which is developing ways to 3D-print structures from concrete. Together they are seeking to use 3D printing and high-performance concrete to manufacture wind turbine bases on-site that could add 80 meters or more to the turbines’ height. What might that look like? COBOD came up with a system that uses a printhead running on an elevated track — like a magic marker with a tip the size of a milk jug. Line by line, the tip releases concrete (a special blend developed by LafargeHolcim) through a print nozzle as it follows its programmed course. “It’s an automated construction factory on wheels that we have, and we could bring it to the site,” said Henrik Lund-Nielsen, COBOD’s founder and general manager.
GE has used 3D printing to make a number of parts for jet engines and gas turbines. It now wants to apply additive manufacturing to the way wind turbine blades are made. GE Renewable Energy and the U.S. Department of Energy set up a partnership earlier this year that will 3D-print turbine blade tips that could be lighter and stiffer compared to current designs, and even recyclable.
Fit to print: The last 10 to 15 meters of a wind turbine blade (the “tip”) captures as much as 40% of the wind energy that spins the generator. That’s why they are the focus of this 25-month, $6.7 million project. GE and its partners plan to print a full-size blade tip assembled from a 3D-printed, skeleton-like structure, and covered with thermoplastic skin. The GE team and its partners, the Oak Ridge National Laboratory and the National Renewable Energy Laboratory, plan to test the structural properties of one tip in a lab and expect to install another three tips on a wind turbine. GE Renewable Energy’s subsidiary LM Wind Power, which makes blades for onshore and offshore turbines, could eventually use the technology on an industrial scale.
LM Wind Power is one of the world’s largest makers of blades for wind turbines. These blades are designed to last for more than 20 years, but what happens to them when they are done spinning? Too often they end up in landfills, lined up like dinosaur bones, because viable recycling solutions are not widely available. LM Wind Power wants to change that. The company, which became carbon neutral in 2018, is working with the wind industry and recycling industry to scale up sustainable solutions for recycling blades that are already in use, while at the same time designing blades that can be more easily recycled in the future.
Group effort: Last fall, LM Wind Power’s parent company, GE Renewable Energy, partnered with Veolia North America to co-process decommissioned blades in the manufacturing of Portland cement, the most common ingredient in concrete. And in January, a group of Danish companies that includes LM Wind Power won funding from the country’s authorities for a three-year project, DecomBlades, focused on upscaling recycling technologies for decommissioned blades. GE Renewable Energy will also collaborate with Carbon Rivers, a startup at the University of Tennessee in Knoxville, and other partners to develop a system for recycling glass fiber from blade parts. And LM Wind Power is also working with its supply chain to identify opportunities “Preventing waste before it occurs is the best way to reduce our impact on the planet, and it’s simply good business,” says Hanif Mashal, vice president of engineering and technology at LM Wind Power. The company’s waste reduction in blade manufacturing has yielded more than $33 million in savings since 2016.
Wind’s a renewable source, of course — but that’s not the same as being unlimited, according to a fascinating new paper in Nature Energy. It finds that giant turbines at wind farms suck in so much moving air that they can cause detectable decreases in wind speeds as far as 30 miles away, giving the upwind farmer a distinct advantage over the downwind farmer and emphasizing the need for more careful planning. The realization that there’s only so much wind to go around in a given region is also fueling work at GE Research, where lead mechanical engineer Lawrence Cheung has been harnessing the power of modern supercomputers to gain an elaborate understanding of how wind works in the real world. Knowledge like that is increasingly valuable for countries and energy producers seeking the most optimal arrangement of renewable sources of energy.
Not just hot air: Cheung’s latest work can model airflow across a wind farm that spans 5,000 acres (or more than 3,780 football fields). Known as computational fluid dynamics simulations, his supercomputer models break wind farms up into hundreds of millions of individual cubic meters for a granular understanding. His goal isn’t to eliminate the wind-wake problem, but to understand the precise impact of the slower air after it passes through a turbine in different wind farm configurations. That way, the cost of reducing wind wake can be weighed against the price of building farms with more widely spaced turbines. With coordinated wind energy development, everybody win(d)s.
Fun fact: Engine turbines, including those in airplane engines, can run hotter than the melting point of their parts — yet the parts don’t melt. That may seem counterintuitive to most of us, but it’s all in a day’s work for engineers at GE Research, who pursue a deep understanding of how heat flows through engine turbines. Why? Because it’s a key element to a broader challenge: Given the central role turbines play in aircraft engines and electrical generation, even tiny tweaks in design could lead to enormous savings in cost and efficiency. Part of that work involves running computer simulations, said GE Research engineer Rick Arthur: “Just like biologists use microscopes or astronomers use telescopes, high-fidelity simulations empower researchers to see what they otherwise could not.” The fidelity’s about to get even higher, as GE Research has been granted the use of one of the world’s fastest supercomputers.
Sim city: That’d be Summit, housed at Oak Ridge National Laboratory in Tennessee. The supercomputer will allow the researchers to create realistic simulations of turbulent heat flows coursing through engines better than they could with older computer models of turbines, which simply couldn’t process the data fast enough. “It opens up a whole new area of predictions we never would have been able to do,” says Michal Osusky, a lead thermosciences engineer at GE Research. “It wasn’t that the methodology wasn’t there. It’s more that the computing resources weren’t there at the necessary scale.”