Cleaner energy the focus of PNNL research at ARPA-E
February 21, 2014
Power transmission, lightweight metals, cheaper cooling, natural gas cars & more on tap
NATIONAL HARBOR, Md. –
Researchers from the Department of Energy's Pacific Northwest National Laboratory will exhibit their work at the 2014 Energy Innovation Summit of high-impact energy research funded by DOE's Advanced Research Projects Agency-Energy, or ARPA-E. The summit runs Feb. 24-26 at the Gaylord Convention Center in National Harbor, Md. Below is an overview of PNNL research that will be highlighted there.
Advanced computing to make power transmission more efficient
Electricity generated at power plants starts its journey toward our homes through massive transmission lines. To prevent overloading the lines and potentially causing blackouts, transmission line owners calculate how much power their lines can carry. Determining each line's capacity, called a path rating, is a labor — and computationally intensive process that results in very conservative estimates. Conservative path ratings leave transmission lines carrying significantly less electricity than they're capable of. Sometimes power providers have to reject available electricity because transmission lines aren't rated to carry it all, causing us to miss out on inexpensive power. Instead of building costly new transmission lines, PNNL researchers are using supercomputers to more accurately determine a line's path rating. PNNL engineer Henry Huang and his colleagues are developing sophisticated algorithms and software programs to determine the true capacity of transmission lines with live, real-time data. The goal is to make transmission lines up to 30 percent more efficient. Quanta Technology, PowerWorld and the Bonneville Power Administration are partners in the project. PNNL's Ruisheng Diao is attending the summit on behalf of the research team.
Fuel-efficient cars & planes with magnesium from the ocean
The U.S. has set ambitious gas mileage targets for cars and trucks, and lightweight metals are needed to meet those goals. Magnesium is used in in some key parts for vehicles and airplanes, but it's about seven times more expensive than the steel that's traditionally used. And much of the magnesium the U.S. consumes comes from often-unpredictable sources abroad. PNNL Laboratory Fellow Pete McGrail and his colleagues are developing a less expensive, more energy-efficient process to extract magnesium from seawater or brine. The process will rely on a new, titanium-based catalyst that regenerates an important chemical in the process. Commercial magnesium production using the system is expected to cost less than $1.50 and require just 25 kilowatt-hours of energy per kilogram. PNNL is developing a prototype system using the new process with partners Global Seawater Extraction Technologies and US Magnesium.
Novel adsorption chiller keeps troops cool with less fuel
Soldiers stationed at remote bases during times of conflict rely on diesel to have working lights, cool air and other basic necessities. Long supply convoys deliver those fuels, but are often attacked, resulting in American injuries and deaths. PNNL Laboratory Fellow Pete McGrail and his colleagues are developing a new, energy-efficient air chilling system that would keep troops on the front lines cool while using about half as much diesel as current systems. PNNL's system will use a next-generation adsorption chiller that is smaller, lighter and more efficient while operating under extreme temperatures. The chiller will use a novel nanomaterial called a metal organic framework that can hold four times more water than the silica gel used in today's adsorption chillers. The nanomaterial was performance tested for three months in the world's first demonstration of an adsorption chiller running with a metal organic framework sorbent. The planned 3-kilowatt unit will weigh about 180 pounds and take up about 8 cubic feet. A prototype of the unit's microchannel adsorption modules will be on display at the booth.
Novel dehumidifier enables energy-efficient evaporative cooling to work anywhere
Americans spend tens of billions of dollars annually on electric bills to power their air conditioners, but there's a more energy-efficient and less expensive cooling option. Evaporative cooling cools hot air by sending a fine mist of water through air. Normally, evaporative cooling isn't possible when air is exceptionally humid or if water is in short supply. But PNNL chemical engineer Wei Liu and his team are developing a novel membrane dehumidifier to make evaporative cooling possible in all climates. The dehumidifier uses a thin membrane that acts like a molecular sieve and soaks up moisture from the air. The membrane consists of thin, foil-like metal sheets that are coated with a water-attracting material called zeolite. As humid air flows through the dehumidifier, water vapor is removed and condensed. In dry climates, the recovered water can be injected back into air to enable evaporative cooling. And in humid climates, the dehumidifier removes the extra moisture in air that usually prevents evaporative cooling. Recently, a membrane dehumidifier prototype made with 50 membrane sheets was made, tested and shown to dehumidify about 800 liters of air per minute. Based on this test, an air-cooling system consisting of PNNL's membrane dehumidifier and an evaporative cooler unit is expected to have a coefficient of performance — a measurement of energy efficiency — that's double conventional air-conditioning technologies. The team plans to develop a one-ton dehumidification and evaporative cooling prototype. PNNL's project partners include Texas A&M University and ADMA Products, Inc.
New fuel storage tanks lighten the load for compressed natural gas vehicles
With the nation's supply of natural gas abundant and inexpensive, the fuel may be a cleaner way to power light-duty cars and trucks. More than 15 million natural gas vehicles operate throughout the world, while about 150,000 are running on America's roads. One challenge is that natural gas exists as a vapor, meaning it contains less energy per volume than the denser, liquid gasoline most of us pump into our cars. Natural gas must be compressed into a pressurized fuel tank to increase its energy density. PNNL engineer Kevin Simmons and his team is developing special, lightweight fuel tanks that make better use of the limited space available in vehicles. PNNL's fuel tank design uses a unique manufacturing method called superplastic forming. The method involves welding and joining together metal sheets and tubes at specific points and blowing air in between the sheets to expand them, forming internal structures like an air mattress. The expanded metal tank will conform to more of a vehicle's space than traditional cylinder tanks. It also helps the cars weigh less, which makes them more fuel-efficient. The PNNL tank is expected to cost $1,500-$1,800 to manufacture and pack 11 megajoules of energy per kilogram, about twice the energy density of today's metal compressed natural gas tanks. Hexagon Lincoln Composites is a partner in the project.
Rare earth-free magnet makes electric motors cheaper with more abundant materials
From wind turbines to electric vehicle motors, magnets play an essential role in a variety of today's electronic devices. But there's a limited supply of the rare earth minerals that are traditionally used in these magnets. In particular, dysprosium is added to increase a magnet's operating temperature, which is high in motors. But dysprosium has been named a critical material with unstable availability. PNNL materials scientist Jun Cui and his team are developing a manganese-based nano-composite magnet that doesn't contain dysprosium or any other rare earth mineral. The new magnet can operate at 200 degrees Celsius. The team's short-term goal is to make a permanent magnet with 15 MGOe, or megagauss-oersteds, a measurement of magnetic energy. The team has already created a magnet that reaches 8.3 MGOe at room temperature. With additional funding, the team will develop a 20-MGOe magnet, which would be more useful for a broader set of commercial applications. Project partners include Ames Laboratory, Electron Energy Corp., United Technologies and several academic institutions: the universities of Maryland, Texas at Arlington, Nebraska-Lincoln, Alabama, Delaware and California San Diego, as well as Mississippi State University and Kansas University.
Nighttime solar power with cheaper thermal energy storage
Solar power is a clean source of energy, but its use is limited to when the sun shines. One option that extends solar energy into the night involves capturing the sun's heat during the day and releasing it when it's dark. Called thermal energy storage, the practice has been limited because the molten salts typically used to store solar heat for power production require large, expensive equipment. PNNL materials scientist Ewa Rönnebro and her team have shown that a powder made of a proprietary metal hydride can store up to eight times more heat per mass than molten salts and operate at higher temperatures. PNNL successfully operated a thermal energy storage prototype based on 10-kilogram hydride material. The prototype showed a volumetric energy density of 200 kilowatt-hours per cubed meters, which is more than eight times higher than state of the art.
The summit's Technology Showcase, where PNNL project booths are located, is open Tues., Feb. 25 and Wed., Feb. 26. Click here for a map of the Technology Showcase layout, including PNNL booth locations. Press passes for the 2014 Energy Innovation Summit can be obtained by visiting the summit's press website here.
Tags: Energy, Energy Efficiency