Often, the narrative around natural disasters is one of resilience. When communities rally and rebuild from catastrophe effectively, they look to and lean on one another. But, what if the catastrophe is a power grid failure?
Widespread power failure would add compounding and crippling damage to already-fraught conditions. Schools, hospitals and elder care operations would be literally and figuratively powerless. How long is too long before the power grid supporting them bounces back?
It turns out that resilience is an important component of the power grid, too.
Temple University Assistant Professor of Electrical Engineering Xiaonan Lu is part of a large, collaborative research project seeking to define more reliable and resilient distribution grids using solar energy. The project is funded by the U.S. Department of Energy and led by Argonne National Laboratory, and includes partners Illinois Institute of Technology, Southern Methodist University, and United Technologies Research Center.
"Because this is supported by the Solar Energy Technologies Office (housed within the Department of Energy) we are taking a particular focus on how solar energy can support grid resilience," Dr. Lu said. "It is also related to the research with microgrids: small, local, self-sustainable systems that can power critical infrastructure using local sources."
Even outside the disaster context, intermittent outages are an economic issue as well, with momentary outages costing the U.S. economy billions annually.
A power grid is a collection of power sources, power users and a central control system. A microgrid is freestanding and often smaller, such as a collection of buildings. Essentially, if the larger grid fails for any reason, a microgrid can still support the building or buildings connected to it.
Dr. Lu's team is looking to leverage a number of technical objectives, such as using bi-level frameworks, regulating resilient frequency and voltage in isolated distribution grids and examining using microgrids built into a reconfigurable network and optimized accordingly.
"We already have grid assets in the system. It is important for us to use these assets to do more," Dr. Lu said.
For instance, besides pairing energy storage systems with solar energy sources, diversified "behind-the-meter" technologies can also be leveraged, including demand response and other "distributed energy resources" like residential solar panels. According to the team's proposal, aggregation of solar energy and behind-the-meter technologies can effectively balance the power generation/consumption among the corresponding assets with additional room for cost reduction.
"Instead of just injecting solar power in the grid, we are trying to develop some control algorithms for commercial solar sources, so they can inject solar power into the grid into a programmable or controllable way," Dr. Lu added.
Rather than relying on conventional (or fixed) microgrids, the project also focuses on dynamic microgrids. As Dr. Lu described, dynamism comes in the form of so-called smart switches to help wall the system off when there is a fault or natural disaster. If successful, the work could lead to the resilient operation of distribution grids with dynamic microgrids and reduced outage time of critical loads.