As the search for reliable, sustainable and flexible power options for the future continues, scientists at the U.S. Department of Energy’s (DOE) Oak Ridge National Laboratory (ORNL), Oak Ridge, Tenn., are working on a new program that focuses on the medium-voltage power electronics grid and power conversion for greater energy efficiency.
Research will be conducted as part of the Medium Voltage Resource Integration program, or MERIT, which brings together four national labs, five universities and other stakeholders to focus on devices that work in the middle range between 1,500V and 50,000V.
ORNL will be guiding the MERIT project, funded under DOE’s Grid Modernization Initiative through the Grid Modernization Laboratory Consortium.
In August 2023, the DOE announced funding of up to $39 million for projects in conjunction with its DOE National Laboratory on electricity grid innovation, including MERIT, which received more than $13 million. According to DOE, “the project intends to develop modular, cost-effective and scalable technologies at medium voltage (4.16 kV to 34.5 kV) that will reliably integrate a range of distributed energy resources (solar, wind, fuel cells, etc.) on to the grid.”
Participating national labs in the program in addition to ORNL include the National Renewable Energy Laboratory, Pacific Northwest National Laboratory and Sandia National Laboratory. MERIT partners include Eaton, Southern Co., Viridi Parente, OPAL-RT, Florida State University, the University of Arkansas, Virginia Tech and the University of Colorado.
According to a February 2024 release by ORNL, scientists are “looking for a happy medium to enable the grid of the future, filling a gap between high and low voltages for power electronics technology that underpins the modern U.S. electric grid.”
ORNL researchers are building medium-voltage, solid-state circuit breakers to develop medium-voltage power electronics in GRID-C laboratories, a specialized research simulation environment that tests innovative technologies focusing on reliability and resilience. In addition, the medium-voltage sector is expected to help achieve clean energy goals and expand capacity in an overburdened power grid, without erecting thousands of miles of new transmission lines, according to ORNL.
Developing devices for medium voltage
Prasad Kandula, ORNL research staff scientist and leader of the Grid Systems Hardware Group, says many different applications can fit this type of power grid, but the technology for the middle space hasn’t yet been proven reliable and cost effective. As such, ORNL will be overseeing the MERIT program in which the labs and universities develop specific devices that operate efficiently within that middle range.
ORNL’s Kandula points out other benefits of operating devices in the middle range, including:
- Medium-voltage power electronics are now more cost effective, and these devices could reduce the size, weight and volume of a system.
- Power conversion using medium voltage can be more efficient and bring more power to smaller spaces.
- Medium-voltage power electronics could be used to help power electric vehicles more reliably, with additional options for integrating systems and power grids.
- These electronics could also be used to bring electricity from one region to another based on demand. Medium-voltage power electronics could also convert AC to DC during distribution, using DC’s efficiencies at carrying longer distances and increasing the amount of delivery capacity using the same power lines.
- Addressing this technology gap could help meet new electric grid capacity needs and demands today and yield economic development benefits in the future.