U.S. Department of Energy - Energy Efficiency and Renewable Energy
Fuel Cell Technologies Office
DOE Issues a Request for Information: Requirements for Fuel Storage Subsystems for Early Market Fuel Cell Applications
October 30, 2009
The U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) issued a Request for Information (RFI) seeking input from prospective fuel cell system users, fuel cell component and system suppliers, and other stakeholders on performance and cost requirements for fuel storage subsystems for near-term, early market fuel cell applications (e.g., for mobile applications such as forklifts, stationary back-up power, and portable power).
This RFI is intended to be “fuel neutral” with a focus on defining the fuel storage needs and requirements for early market fuel cell applications to facilitate successful market transformation in a competitive environment. This information will be used by DOE in a preliminary assessment and ultimate determination of the storage system performance requirements.
To respond to this RFI, read the Request for Information (PDF 133 KB), respond to the four questions/issues on page four, and send an e-mail to StorageTargets2009@ee.doe.gov with the responses attached using Microsoft Word (.doc) format by January 15, 2010. [Editor's note: The deadline was extended on December 15, 2009. See the new RFI announcement.] Download Adobe Reader.
Questions and Answers
Below are questions about the RFI from responders followed by answers.
The RFI states that efficiency of the overall fuel cell system must not be reduced by more than 10% if heat is needed to release the fuel. It is not clear what that means. Is it 10 percentage points, net? 10% of the starting value? What is meant by "release the fuel"? Does this mean the hydrogen, or some other fuel? Does it mean release from a storage medium such as a metal hydride?
This question refers to the "note" added to the end of the Purpose section of the RFI, which states: "Note: In addition to the operating and cost requirements to be determined, the storage system must not reduce overall fuel cell efficiency by more than ~10% if heat is needed to release the fuel."
The note simply means that if additional energy is required to operate or release the fuel from the storage, it cannot reduce the overall energy output by more than 10%. For instance, if fuel is burned to produce heat to release additional fuel from the storage, then no more than 10% of the stored fuel may be consumed; or if electrical energy from the fuel cell is used to pump fuel solutions, then, again, no more than 10% of the total fuel cell output may be consumed.
Please note that this does not include "waste" heat that would normally be rejected from the system because it would not decrease the normal energy output from the system. Also, "fuel" is used because the RFI is not specific to hydrogen fuel cell systems; therefore, it would, for instance, refer to hydrogen for hydrogen-polymer electrolyte membrane (PEM) systems, methanol for direct methanol fuel cell (DMFC) systems, or NaBH4 solutions for direct NaBH4 fuel cell systems.