Excess energy from coal-fired power plants could be stored in underground salt caverns for future use by the Kansas Geological Survey and the energy company Evergy.
“Excess electricity can be used to split water into hydrogen and oxygen gas,” said Franek Hasiuk, KGS geologist and principal investigator for the project. “The hydrogen can then be stored in salt caverns for later use, either by burning it with natural gas in the power plant, adding it into pipeline natural gas for burning in home furnaces and stoves, supplying it to another business for use in chemical processes like fertilizer production, or using it to power vehicles.”
For decades, natural gas and coal-fired plants were the power industry’s mainstay, designed to meet the needs of consumers at all times. Rather than relying solely on renewable energy sources like wind, solar, and nuclear, electrical grid operators are increasingly relying on fossil fuels like coal and natural gas.
As a result, the plants sit idle for long periods of time, wasting money and resources. However, if a plant could remain operational and store excess energy for future use, it would be more cost-effective.
“Hydrogen storage could allow Evergy to store large amounts of energy to deal with the problem of intermittent power production from renewables – no solar when it’s night, no wind power when it’s not windy,” said Hasiuk.
In Kansas, there are vast salt beds beneath the surface. More than 37,000 square miles of Kansas’ central and southern subsurface are covered by the Permian-era Hutchinson Salt Member, which has a maximum thickness of more than 500 feet. Other parts of Kansas, including western and southwestern Kansas, have thick salt layers as well.
Since the late 1800s, salt has been mined in Kansas. Natural gas, natural gas liquids, and other hydrocarbons are now stored in salt caves, some of which were formed during salt mining and others which were excavated specifically for this purpose.
These underground salt caverns will be studied by the KGS in conjunction with the U.S. Department of Energy and Evergy, which received a $200,000 grant. Maps of potential salt beds will be created using modern digital techniques.
“Right now, it’s unclear whether undertaking a project like this is feasible for energy companies,” Hasiuk said. “Our study will help reduce the uncertainties related to hydrogen storage. At the end of the study, we may find out the costs of underground storage are as risky as or more risky than thought, but we should certainly be more confident about just how risky it is.”
Following a year of testing, the partners hope to demonstrate the viability of hydrogen storage before moving onto more complex engineering and design work on a storage system. Phase 2:
