[ storage ]
Hydrogen as a long-term storage solution
Hydrogen is uniquely suited to meet this challenge , particularly for long-term seasonal storage . Figure 2 illustrates how hydrogen can store large amounts of energy , making it a viable option for large-scale storage . Storing hydrogen in underground caverns is also the most economical method , with costs ranging from $ 20 to $ 100 per MWh , compared to the exorbitant costs of battery storage , which can range from $ 100,000 to $ 200,000 per MWh .
AFC ’ s legacy and limitations
The alkaline fuel cell ( AFC ), invented by British engineer Francis Thomas Bacon , is the most effective fuel cell technology . AFCs use hydrogen and pure oxygen to generate
electricity , heat , and water , with efficiencies of around 70 %. NASA adopted AFC technology for its space programmes in the 1960s , relying on it for the Apollo and Space Shuttle missions .
One of the key advantages of AFCs is that they do not rely on rare earth metals or per- and polyfluoroalkyl substances ( PFAS ), both of which are becoming environmental concerns in other fuel cell technologies . AFCs have a simple design that enables long operating life , making them well suited to long-term energy storage . However , AFCs face challenges when using air as a source of O 2
. Air contains small amounts of CO 2
, which reacts strongly with the KOH electrolyte to form potassium carbonate ( K 2
CO 3
). The gradual conversion of KOH to
K 2
CO 3 reduces both the efficiency and lifetime of the system .
Fig . 2 . Storage capacity plotted against discharge time
Hydrogen Tech World | Issue 19 | December 2024 17