Hybrid Fuel/Energy: April 2008 Archives

The gathering was symbolic of a growing realization that in matters of economic development, the South has learned the importance of teamwork. In the case of transportation, this regional teamwork has resulted in the cooperation of lawmakers, business leaders and research institutions on a broad array of initiatives, from creating new fuels to helping the world's auto manufacturers build lighter, stronger, more energyefficient cars and trucks.

ORNL Leader in Transportation Research

Oak Ridge National Laboratory for years has been the leader in transportation research for the Department of Energy's energy efficiency programs. More recently, the Laboratory has sought to connect to the growing automotive presence in the Southeast. The region is now home to 3,000 automotive suppliers and 10 major automotive assembly plants including Toyota in Kentucky and Mississippi; BMW in South Carolina; Ford in Georgia; Mercedes, Hyundai and Honda in Alabama, as well as Saturn and Nissan—which recently relocated U.S. headquarters to Nashville—in Tennessee.

Universities and ORNL Provide Research for Supply Chain, Sustainable Manufacturing, Heavy Vehicle Research, Power Electronics, Engines and High-Performance Materials

Surrounding these plants is a set of universities that, along with ORNL, represent extensive expertise in supply chain management, sustainable manufacturing, heavy vehicle research, power electronics, engines and high-performance materials. In 2007, ORNL and the University of Tennessee, along with six southern research universities, announced the Automotive Research Alliance, a regional effort to provide southern automakers access to unique research capabilities.

Research capabilities outside automakers' own R&D organizations are crucial to development of new technologies and products, says Tom Bologa, vice president of engineering, United States, for BMW of North America. 

Detroit Center Coordinates ORNL, DOE, DOD and Automotive Suppliers

Although the South's largest research laboratory, ORNL is not restricting automotive research efforts to the Southeast. The Department of Energy recently announced an initiative headquartered at automotive supplier Delphi Automotive's former R&D center in Detroit that pulls together ORNL, DOE, the Department of Defense and a consortium of automotive suppliers. Called USAutoPARTs, the effort will provide both expertise and facilities to second- and third-tier automotive suppliers, most of which cannot afford a program of in-house research.

SOURCE: ORNL overview of automotive alternative energy research

Plug-in hybrid electric vehicles may have an unexpected value.

One car of tomorrow may not only get its energy from the grid but also may give "imaginary power" back to the grid. The plug-in hybrid electric vehicle envisioned by the Department of Energy would be plugged at night into a home wall outlet, connecting the car to a local electrical distribution system that would recharge the battery. The next day the car would travel using a combination of stored electric energy and fuel. According to a vision of Oak Ridge National Laboratory researchers, the car's charger would supply the grid with "reactive power," or non-active power, to help regulate local utility voltage.

To convert the alternating current from the local electrical distribution system to the direct current needed by the car's battery, a rectifier, or charger, is required. Conversely, an inverter is needed to convert direct current to alternating current. The car would use alternating current to power the drive motor. The rectifier, or charger, could be located either in the car or at facilities designed specifically to recharge batteries of plug-in hybrid electric vehicles parked for extended periods at, say, apartment complexes, hotels and parking garages.

Inverters have several uses, including the ability to inject reactive power to the grid or absorb this imaginary power from the grid. This helps regulate the voltage on distribution and transmission systems. Inverters can prevent "micro-voltage collapses" that frequently occur in the western United States. Such sudden voltage dips can cause dimming of lights, computer crashes, damage to equipment and destruction of semiconductor wafers during manufacture.

Automobile Industry Optimizes Plug-in Hybrid Engine, Motor and Battery Operation

DOE researchers are working with the U.S. automobile industry to optimize plug-in hybrid engine, motor and battery performance for efficient vehicle operation. ORNL and University of Tennessee power electronics experts at the National Transportation Research Center are seeking to improve inverter design to make the device smaller, lighter and less expensive. ORNL is a member of the Plug-in Hybrid Development Consortium.

DOE also supports research on one way to reduce peak demands on the electric grid: deploy distributed energy resources—microturbines, fuel cells and photovoltaic panels—to provide electricity to both local buildings and the electric grid. The plug-in hybrid could be considered another distributed energy resource, but one that also stores energy.

Electric Grid for Distributed Energy System Benefits from Plug-In Vehicles

ORNL researchers led by Stan Hadley have found that the U.S. electric grid will operate more efficiently as more Americans charge the batteries in their plug-in hybrid vehicles after 10 p.m., when the electric load on the system has dropped to almost zero and the wholesale price for energy is least expensive. The researchers have analyzed the potential impacts of plug-in hybrid electric vehicles on electricity demand, supply, generation structure, prices and associated emission levels in 2020 and 2030 in 13 regions as specified by the North American Electric Reliability Council and DOE's Energy Information Administration.

Their study assumed that by 2020 a mixture of sedans and SUV plug-in hybrids would make up one-quarter of the cars sold. They performed calculations using the Oak Ridge Competitive Electricity Dispatch model, which was developed at ORNL over the past 12 years to evaluate a wide variety of critical electricity sector issues.

The ORNL researchers ran seven scenarios for each region for 2020 and 2030. In each scenario they assumed these vehicles plugged in starting at either 5 p.m. (early evening) or at 10 p.m. (nighttime) and remained until fully charged.

"We concluded that most regions must build additional electrical generating capacity or rely on demand response to meet the added demands from plug-in hybrid electric vehicles in the early evening charging scenarios," Hadley says. "This need will be critical by 2030 when plug-in hybrids will likely have a larger share of the installed vehicle base and thus exert a greater demand on the electrical system."

Accommodating the peaks and valleys of electricity use is a major challenge for generators and transmission operators. Ideally, customers would reduce their consumption of electricity at peak load times in response to market prices or a utility's request. During hot summers, the demand for air conditioning between 2 and 6 p.m. can boost the peak load to the point that a utility must purchase power from another utility at a higher price. In sharp contrast, the grid on the same night may be so underutilized that energy is sometimes given away.

Smart Chargers for Distributed Energy System

Another potential advantage of wide usage of plug-in hybrids is that charging stations can help regulate local voltage. Researchers at ORNL's Distributed Energy Communications and Control laboratory plan to test this concept.

Smart chargers are needed to avoid negative impacts on the distribution system. For example, if several plug-in hybrid pickup trucks with 250-kilowatt batteries were recharged in 10 minutes on a feeder without a smart charger, the distribution system's reliability could be threatened. In one project, ORNL's Burak Ozpenici is examining possible rectifier designs that would perform rapid charging while providing reactive power compensation.

SOURCE: ORNL Distributed Power Update