page_title: Hydrogen storage
section_title: Automotive Onboard hydrogen storage
hierarchical_section_title: Hydrogen storage / Automotive Onboard hydrogen storage
context_page_description: Hydrogen storage is a term used for any of several methods for storing hydrogen for later use. These methods encompass mechanical approaches such as high pressures and low temperatures, or chemical compounds that release H₂ upon demand. While large amounts of hydrogen is produced, it is mostly consumed at the site of production, notably for the synthesis of ammonia. Interest in hydrogen storage is driven by the idea that it could be a medium for storing energy, e.g. to compensate for intermittent energy sources. The overarching challenge is the very low boiling point of H2: it boils around 20.268 K. Achieving such low temperatures requires significant energy.
context_section_description: Targets were set by the FreedomCAR Partnership in January 2002 between the United States Council for Automotive Research (USCAR) and U.S. DOE (Targets assume a 5-kg H₂ storage system). The 2005 targets were not reached in 2005. The targets were revised in 2009 to reflect new data on system efficiencies obtained from fleets of test cars. The ultimate goal for volumetric storage is still above the theoretical density of liquid hydrogen.
  It is important to note that these targets are for the hydrogen storage system, not the hydrogen storage material. System densities are often around half those of the working material, thus while a material may store 6 wt% H₂, a working system using that material may only achieve 3 wt% when the weight of tanks, temperature and pressure control equipment, etc., is considered.
  In 2010, only two storage technologies were identified as having the potential to meet DOE targets: MOF-177 exceeds 2010 target for volumetric capacity, while cryo-compressed H₂ exceeds more restrictive 2015 targets for both gravimetric and volumetric capacity (see slide 6 in ).
  The existing options for hydrogen storage require large storage volumes which makes them impractical for stationary and portable applications. Portability is one of the biggest challenges in the automotive industry, where high density storage systems are problematic due to safety concerns.
  Fuel cell powered vehicles are required to provide a driving range over 300 miles—this cannot be achieved with traditional storage methods. A long term goal set by the Fuel Cell Technology Office involves the usage of nanomaterials to improve maximum range.
caption: Targets for on-board hydrogen storage assuming storage of 5 kg of hydrogen.[81]