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Fig . 4 . H-Battery process diagram , functioning as a fuel cell
Key specifications of the H-Battery
The H-Battery achieves remarkable performance metrics , including :
• Electrolysis efficiency : ~ 90 % electricity-tohydrogen conversion , with ~ 5 % waste heat recoverable as process water
• Fuel cell efficiency : ~ 70 % hydrogen-toelectricity conversion , with ~ 25 % waste heat recoverable as process water
• Water use : 270 litres of clean water per MWh , stored and reused
• Plant efficiency : A combined > 50 % round-trip efficiency , plus waste heat and CO 2 capture benefits
• CO 2 capture : At least 80 %, with a capture rate of 12 tonnes of CO 2 per year for a 1-MW system running at full load as a fuel cell
• Operating costs : € 35 per tonne of CO 2 captured , with OPEX of € 300 per MWh for heating
• Material use : 19 tonnes of slaked lime per year for a 1-MW system running 100 % as a fuel cell , resulting in 31 tonnes of limestone by-product ( storing 440g of CO 2 per kg of limestone ).
• CO 2 capture efficiency : 1.4 g / kWh to 14 g / kWh ( standard to optimized DAC version )
H-Battery electrolysis efficiency
The electrolysis process achieves ~ 90 % efficiency by eliminating bubbles in the electrolyte . This is a key advantage of the H-Battery design , which benefits from the same triple-point phenomenon that enables efficient fuel cell operation . The absence of bubbles means that balance of plant ( BoP ) components , such as degassing tanks , are not required , nor are membranes , which are often a limiting factor in other systems . This not only increases efficiency , but also eliminates the need for PFAS , addressing a significant environmental concern .
Hydrogen Tech World | Issue 19 | December 2024 19