In the aftermath of a crippling winter storm that left millions of Texans without power, water and heat, a group of engineers at the Walker Department of Mechanical Engineering hope their research on long-duration energy storage in Texas will keep such a crisis from happening again.
The storms exposed limitations and failures at multiple levels. But, the key to avoiding future catastrophes lies in storing large quantities of energy -- enough to compensate for supply shortfalls resulting from loss of generation or demand spikes.
“After the oil embargo in the '70’s, the Strategic Petroleum Reserve was set up to cushion against future oil supply shocks," said Associate Professor Vaibhav (VB) Bahadur, one of the leaders of the project. "We store 30 days’ worth of domestic oil consumption presently. This crisis highlights the need for similar large-scale storage options for electricity.”
Bahadur led this project with Mark Kapner, a former senior strategy engineer at Austin Energy, and doctoral students Enakshi Wikramanayake and Palash Acharya. Their research was recently accepted by IEEE’s Green Technologies Conference.
Green hydrogen represents a promising option to increase energy storage capacity. It's considered ‘green’ because the hydrogen is produced using surplus energy from wind and solar sources to split it from water. When needed, hydrogen can produce electricity via fuel cells, or as a fuel in existing natural gas power plants.
In an analysis of ERCOT (Electric Reliability Council of Texas) data on projected electricity generation and demand, the team found two periods where wind and solar generation consistently exceeded the daily load, creating a need for long-term storage for that extra energy. And hydrogen is superior to batteries for that type of storage. Hydrogen storage can increase renewable contribution to electricity production in Texas by 16% and can be stored for months, in contrast to large scale batteries.
“Texas is the largest producer of wind energy in the U.S., and we have plenty of sunshine as well. We found several instances where those conditions created surplus wind and solar energy that needs to be stored,” said Acharya, one of the graduate researchers.
While hydrogen might sound like an exotic fuel, it is well understood by the engineering and scientific community. Texas is the largest domestic producer of hydrogen, and already has a network of hydrogen pipelines in place. Plus, Texas’s sprawling network of natural gas pipelines can be used to transport hydrogen with minimal retrofitting. Well-established industrial practices exist for generation, storage and handling.
While the cost of green hydrogen remains high compared to other sources, it is rapidly falling as due to investments and technological improvements. Overall, green hydrogen is poised to be a global disruptor in energy markets as countries in Europe and Asia have already made significant investments. Notably, hydrogen is also a growing area of research at UT Austin. Bahadur believes large-scale hydrogen energy storage could become viable by 2025, if not sooner.
“Extreme weather events like hurricanes, floods, wildfires, etc. are unfortunately going to be more common globally," Bahadur said. "We need resilient energy storage systems as part of disaster preparedness, which can also serve as a buffer in the daily fluctuations in wind and solar energy. Above all, this is critical to achieving a zero-emissions grid.”
The team will continue their work on analyzing and promoting the use of green hydrogen. “Until viable solutions are in place, my wife is setting up a disaster preparedness kit in the garage and stocking it up with plenty of water and battery packs” says Bahadur.
