Idaho National Laboratory is working with municipally owned utility Idaho Falls Power to test how small hydropower plants can serve as reliable sources of startup power during outages.
The city of Idaho Falls owns five hydropower plants on the Snake River, from the Upper Power Plant north of the city to the Gem State Dam just to the south. These plants generate enough electricity to meet about one-third of the city’s needs, and the rest of its power is purchased wholesale. All the power on the regional grid is managed by a Balancing Authority.
INL researchers have performed tests to see how the city’s turbines and generators might be ramped up quickly with help from energy storage devices. The project also tested how the utility’s control systems can be made more stable and responsive during emergencies.
Idaho Falls reached out to INL after an outage in December 2013 left about 3,500 residents in subzero cold for three hours. To cope with a Rocky Mountain Power blackout already going on, the Balancing Authority ordered Idaho Falls Power to shed 35 MW in 30 minutes. In 2016, Idaho Falls and INL began investigating “black start” and “islanding” capabilities. Black starting is jump-starting a local grid with equipment and electricity that’s immediately available. Islanding involves powering the local grid when outside power is not available.
By themselves, small hydropower plants can’t restart a localized grid during a widespread outage. But with energy storage, these plants may be able to provide adequate frequency and voltage stabilization to avoid disruption in service.
“The grid is changing very rapidly,” said Thomas Mosier, INL’s energy systems group lead. “What we are focusing on here is using existing power generation in new ways to improve reliability and resilience. The tests performed this week demonstrated that small hydropower plants like Idaho Falls’, combined with integrated energy storage technologies may prove to be as nimble as natural gas when it comes to load following (i.e. responding to demand).”
The tests were especially focused on ultracapacitors, which can deliver quick bursts of energy then just as quickly store energy and capture excess power that might otherwise be lost. To isolate the city’s generators and test them in various configurations, two 6-MW load banks were brought in.
The data collected will be fed into INL’s Digital Real-Time Simulators, which can offer insight into how grids will act and react under different conditions. In preparation for the tests, these computers were used to model possible outcomes and minimize the risks of failure or equipment damage.
“If we can solve this, it opens up capabilities for a lot of communities that have small hydro systems like ours,” said Ben Jenkins, who is managing the project for Idaho Falls Power. “It helps Idaho Falls, but it could have a much broader impact on the national grid.”
INL is a U.S. Department of Energy (DOE) national laboratory that performs work in each of DOE’s strategic goal areas: energy, national security, science and environment.