Features - September 2013
NETL's Supercomputer Addresses Energy Issues on Two Fronts
Massive Computing Power with Minimal Energy Consumption Helps Scientists Design Smarter Fossil Energy Systems
Most of us do our part to reduce energy consumption by some minuscule measure, even if the goal is to save a few bucks rather than save the planet. Switching to high-efficiency light bulbs, driving fuel-efficient cars, and adjusting the thermostat are just a few examples of the small steps we can all take that, collectively, make a big difference.
But have you ever thought about the energy consumed each time you go online? The internet has become a primary means of staying connected in the modern world, and supercomputers, high-performance computing resources, are the engine that drives that connection. These systems consume enormous amounts of electricity, creating a problem that continues to grow as dependence on technologies increases. A single Google™ search consumes electricity equivalent to turning on a 60W light bulb for 17 seconds. Multiply that over 1.6 trillion searches a year conducted globally, and you have a tremendous strain on our energy grid.
NETL’s Simulation-Based Engineering User Center (SBEUC) is tackling this energy hurdle on two fronts. Having installed one of the world’s largest and most energy-efficient supercomputers at the center, NETL has lowered the energy its uses for computation and enabled the laboratory’s researchers to devise more efficient means to produce and use fossil energy.
NETL’s research into clean energy technologies is critical to the nation’s economic and environmental future, according to U.S. Secretary of Energy Ernest Moniz. Dr. Moniz dedicated NETL’s Simulation Based Engineering User Center (SBEUC) at a ceremony in Morgantown, W. Va., in July.
“The SBEUC is accelerating R&D to address environmental concerns around power generation, speed the development of new cutting-edge technology, and enable us to troubleshoot and optimize existing technology,” said Chris Guenther, director of the SBEUC at NETL. “All of the work that once would have been done manually—by building scale models and prototype facilities—can now be done on this computer, much faster than we could have ever done before. It’s all about making research into the next generation of fossil fuel systems faster, cheaper, and safer.”
Because these large, tractor-trailer size facilities can generate a lot of heat, a big chunk of the energy they consume is used for cooling. Similar to how the fuel efficiency of cars is measured in miles per gallon, how efficiently a data center uses power is measured in power usage effectiveness (PUE), the ratio of the total amount of power used by a computer data center to the power delivered to the computing equipment. Most data centers operate at about 1.6 PUE, meaning that for every 100 watts of computing electricity, 60 watts are used to cool the system. The U.S. Department of Energy (DOE) wants that number to drop to 1.4 PUE or better, with a target of 1.2. Designers of the SBEUC in Morgantown have far exceeded that expectation, with a PUE of 1.04.
The secret to the SBEUC’s efficiency is its use of a unique, dynamically controlled air/humidity system. The building enclosure itself is designed to help dissipate heat more effectively, while a high-tech system dynamically adjusts moisture content in the air—in much the same way a humidifier or de-humidifier can make a home more comfortable throughout the changing seasons.
In addition to earning NETL bragging rights for its energy efficiency, the SBEUC gives researchers access to huge parallel computing power. How huge? The system, currently ranked 67th of the Top 500 list of the 500 most powerful computers in the world, is capable of performing 503 trillion operations per second, about 1 million times faster than most high-end desktop computers.
NETL researchers tap into this power in many ways, including virtual experiments in the form of computational fluid dynamics (CFD), a method of using complex numerical models and algorithms to analyze the flow of gases or fluids. While traditional research and development would involve construction of physical models and prototypes, CFD does all of this virtually. High-performance computers crunch the numbers and simulate results, giving researchers an unprecedented view into the intricate details of complex systems. This process reduces experimentation time to weeks instead of years and allows scientists to adjust parameters on the fly. For example, researchers looking to make coal-fired power plant turbines more efficient can simulate the quantity or chemistry of material added to the furnace, the operating temperature and/or various design elements of the turbines to see which yields the most efficient output. And this can all be done at a much lower cost and with zero impact on facility operations and the environment.
The SBEUC is powered by a high-performance computer that allows researchers to simulate phenomena that are difficult or impossible to probe experimentally. The results from simulations are accessible through user centers that provide advanced visualization capabilities and foster collaboration among researchers.
“Previously, if you wanted to look at 10 different cases, or variables, you had to run 3 cases on one set of central processing units, or CPUs, then find another set of CPU cores to run the next 3, and so on,” Guenther said. “Now, with the SBEUC’s large parallel-computing power, you can run all 10 at once, even while several other researchers are using the system to run their own experiments.”
One of the largest experiments running on the NETL system is looking at a process called chemical looping. Conventional combustion uses air as a primary source of oxygen to initiate the burn required to fire the reactor. Chemical looping uses a metal oxide as the oxygen source in a two-stage process that virtually eliminates nitrogen oxides and other pollutants produced in conventional combustion. Because no commercial-scale chemical looping reactors exist anywhere in the world, NETL has built a large-scale, virtual model inside the SBEUC computer. The model is used in conducting experiments on various scenarios to optimize the chemical-looping process. The SBEUC’s massive computing power enables the model to be scaled up or down to support various scenarios.
The SBEUC has enabled NETL to accomplish several specific objectives. One is helping NETL to expand use of its MFiX software, a computer code “template” that researchers use to model bubbling and circulating fluids. These stock calculations provide ready-made data on the three-dimensional distribution of pressure, velocity, temperature, and mass fractions to help researchers study behaviors in multi-phase flows. “The SBEUC is absolutely key to this development effort because it allows us to run and test a huge number of CFD simulations that help us understand how to refine the chemistry,” said Dirk Van Essendelft, chemical and biochemical engineer in the NETL’s Computational Science Division.
Another objective facilitated by the SBEUC is the efficient use of an NETL-developed software program for evaluating fuel systems called Carbonaceous Chemistry for Computational Modeling, or C3M for short. C3M has been used extensively to develop a model of the transport integrated gasifier at the National Carbon Capture Center (NCCC). Located in Wilsonville, Ala., this DOE-sponsored facility provides a test bed to evaluate emerging technologies for reducing greenhouse gas emissions. Using the C3M software and numerical models of the NCCC, researchers can test various scenarios and, when ready, actually deploy their experiments into prototype production at the center.
Few would argue that society must come up with alternative energy sources to meet our future demands, and the push toward renewable sources like wind, solar and even hydroelectric generation are making great strides in that direction. However, there is no silver bullet. For now, and well into the future, fossil fuels will continue to supply the majority of our global energy.
The mission of NETL and its SBEUC supercomputer is to maximize the performance and output of fossil-fuel power generation, while reducing environmental impact until (and if) alternative sources can fill in the gaps. As a strong indicator of this focus and drive, utilization of the SBEUC has remained at about 90 percent of its computing capacity since it opened, meaning researchers are taking full advantage of the powerful resource, and taxpayers are getting the most bang for their buck, with no resources sitting idle or wasted.
Using energy more efficiently now to develop ways to use energy more efficiently in the future is a winning combination for the SBEUC. It’s altogether fitting that this one-two punch is being delivered by NETL, “the ENERGY lab.”