Electrical & Computer Engineering professor Dr. Xiaonan Lu shares his expertise in power grid research and how it can provide guidance on current events.
With each passing day, images from the current power outages in Texas paint a picture that is both terrifying and seemingly preventable. When power generation and consumption reaches a critical mass, it can be hard to look past the immediacy of keeping people warm, fed and healthy to fundamental questions, such as: how did we get here?
Dr. Xiaonan Lu, assistant professor of electrical & computer engineering at Temple University, specializes in power generation and inverter-based microgrids. By his estimation, the current energy situation is largely a problem of balance between energy sources and loads.
"Generally, with power grids, we have a diversified generation mix on the source side, including conventional bulk generators and emerging inverter-based resources. Meanwhile, we as the customers and power consumers are on the load side," Dr. Lu said. "To maintain a reliable and stable grid operation, it is mandatory to balance the source and load power at any time. The recent power outages are essentially induced by insufficient power generation, definitely induced by the severe weather conditions."
According to Dr. Lu, there are multiple solutions to consider, at least in engineering terms--though he noted with caution that it is challenging to completely avoid these situations.
"Power grids are generally operated 'as planned.' In other words, we can roughly foresee how much power we need to reserve. However, in face of grid contingencies, such as the most recent severe weather conditions in Texas, it is sometimes necessary to 'think out of the box' and prepare some back-up resources and energize some critical infrastructures locally, for example, using microgrids," Dr. Lu added.
Microgrids can be designed as some localized self-sustainable energy systems that are commonly powered by distributed inverter-based resources, such as batteries, wind, or solar. These resources can provide 'grid-forming' capabilities to support conventional grids in both normal and contingent conditions.
Operating as support mechanisms in this way can enhance the survivability of critical infrastructure, such as hospitals and nursing homes in the face of 'extreme grid events', which is one of the primary focuses of Dr. Lu's ongoing research with the U.S. Department of Energy.
"Some conventional approaches may leverage existing back-up generators, for example diesel generators, to satisfy short-term energy needs. With 'grid-forming' inverter-based resources and microgrids, we can further enhance the survivability of critical infrastructures," Dr. Lu said, adding that it is "also worth mentioning that these 'grid-forming' resources and microgrids can be interconnected to form networked microgrids." In other words, some mutual support in localized areas can be expected, which would give grid operators a more efficient and more effective grid service restoration plan.
These options are not tied to specific states or localities, as different regions face different challenges: from the current unusual severe snow in Texas to hurricanes in Florida and wildfires in California.
"I think to mitigate the influence of this type of grid contingencies, we can focus on both the 'planning' phase and 'operation' phase," Dr. Lu said. "This way, we can better prepare for the extreme events and also facilitate efficient service restoration."
To learn more about Dr. Lu's research, visit https://sites.temple.edu/ecexiaonanlu.