[ backup power ]
Exploring the efficiency of hydrogen storage in backup power applications
Hydrogen fuel cells have mainly gained attention as an electric vehicle ( EV ) solution . While hydrogen EVs show significant promise , this application only scratches the surface of fuel cells ’ potential . Another use case is to provide backup power .
By Ellie Gabel , Associate Editor , Revolutionized
The potential for hydrogen storage
Backup energy storage is an increasingly crucial resource today . Roughly 70 % of the U . S . national grid is over 25 years old ,¹ making blackouts likely , especially amid rising extreme weather conditions . The growing adoption of renewable energy further drives the need for scalable storage solutions , as solar and wind are intermittent power sources .
Potential challenges
Despite its advantages , hydrogen energy storage is not without challenges . High upfront costs are the most prominent issue . While green hydrogen has a lower cost per storage capacity than batteries , 4 its cost per electrical discharge is higher . These expenses mainly arise from the equipment and infrastructure required for electrolysis and hydrogen storage .
Hydrogen is an ideal medium for these applications . Unlike diesel generators , hydrogen fuel cells do not rely on fossil fuels for operation and do not produce greenhouse gas emissions . Batteries offer similar advantages but degrade over time and rely on volatile , scarce minerals .
It is also worth noting that hydrogen has the highest gravimetric energy density of any fuel . It can store up to 120 megajoules per kilogram ² – almost three times that of gasoline . Although a kilogram of hydrogen takes up far more space than other fuels , it is compressible as a gas . This makes compressed hydrogen a remarkably efficient storage medium for backup power needs , potentially reducing the physical space required for storage .
Hydrogen is also the most abundant element in the universe ,³ which alleviates concerns over long-term resource availability . The same cannot be said for conventional batteries and fossil fuels .
Safety is another potential obstacle . Hydrogen is highly flammable and disperses rapidly in the event of a leak , which can lead to explosions under certain conditions . Considering that 83 % of major power outages are caused by severe weather , 5 such volatility could pose significant risks . The same storm that causes a blackout could affect the stored hydrogen , leading to leaks , fires , or explosions .
One possible solution is converting hydrogen to a safer medium . Storing it as ammonia reduces its combustibility , lowers the risk of leaks , and improves its volumetric energy density . However , this approach adds extra costs and complexity .
Hydrogen as backup storage today
While the challenges of hydrogen energy storage deserve attention , they have not prevented its adoption . The town of Calistoga , California , is building a microgrid capable of providing 48 hours of energy in an emergency through a fuel cell-battery hybrid system . 6 Pairing the two technologies could prove an optimal strategy for addressing cost concerns .
46 Hydrogen Tech World | Issue 20 | February 2025