These tables summarize hydrogen storage technical performance targets for portable power applications. These targets were developed with input to DOE through extensive communications with various stakeholders, industry developers, and end users, including through a 2012 request for information and workshops, as well as additional national lab assessments.
More information about targets can be found in the Hydrogen Storage section of the Fuel Cell Technologies Office's Multi-Year Research, Development, and Demonstration Plan.
Technical Performance Targets a: Hydrogen Storage Systems for Low Power (≤2.5 W) Portable Equipment
| Storage Parameter | Units | 2015 | 2020 | ||
|---|---|---|---|---|---|
| Single-Use | Rechargeable | Single-Use | Rechargeable | ||
| Hydrogen capacity | g H2 | ≤1 | ≤1 | ≤1 | ≤1 |
| System gravimetric capacity b: Usable, specific-energy from H2 (net useful energy/max system mass) c | kWh/kg (kg H2/kg system) | 0.7 (0.02) | 0.5 (0.015) | 1.3 (0.04) | 1.0 (0.03) |
| System volumetric capacity: Usable energy density from H2 (net useful energy/max system volume) c | kWh/L (kg H2/L system) | 1.0 (0.03) | 0.7 (0.02) | 1.7 (0.05) | 1.3 (0.04) |
| Storage system cost | $/Wh net ($/g H2 stored) | 0.09 (3.0) | 0.75 (25) | 0.03 (1.0) | 0.4 (13) |
Technical Performance Targets a: Hydrogen Storage Systems for Medium Power (>2.5 W–150 W) Portable Equipment
| Storage Parameter | Units | 2015 | 2020 | ||
|---|---|---|---|---|---|
| Single-Use | Rechargeable | Single-Use | Rechargeable | ||
| Hydrogen capacity | g H2 | >1–50 | >1–50 | >1–50 | >1–50 |
| System gravimetric capacity b: Usable, specific-energy from H2 (net useful energy/max system mass) c | kWh/kg (kg H2/kg system) | 0.7 (0.02) | 0.5 (0.015) | 1.3 (0.04) | 1.0 (0.03) |
| System volumetric capacity: Usable energy density from H2 (net useful energy/max system volume) c | kWh/L (kg H2/L system) | 1.0 (0.03) | 0.7 (0.02) | 1.7 (0.05) | 1.3 (0.04) |
| Storage system cost | $/Wh net ($/g H2 stored) | 0.2 (6.7) | 1.0 (33) | 0.1 (3.3) | 0.5 (17) |
Portable Power Durability and Operational Targets a
| Storage Parameter | Units | 2015 | 2020 |
|---|---|---|---|
| Single-Use and Rechargeable | Single-Use and Rechargeable | ||
| Durability/Operability | |||
| External operating temperature range d | °C | -40/60 | -40/60 |
| Min/max delivery temperature e | °C | 10/85 | 10/85 |
| Min delivery pressure from storage system | bar (abs) | 1.5 | 1.5 |
| Max delivery pressure from storage system | bar (abs) | 3 | 3 |
| External temperature f | °C | ≤40 | ≤40 |
| Discharging Rates | |||
| Minimum full flow rate | (g/s)/kW | 0.02 | 0.02 |
| Start time to full flow (20°C) | s | 5 | 5 |
| Start time to full flow (-20°C) | s | 10 | 10 |
| Transient response 10%–90% and 90%–0% | s | 5 | 2 |
| Fuel Purity | |||
| Fuel purity (H2 from storage) g | % H2 | Meets applicable standards | |
| Environmental Health and Safety | |||
| Toxicity | Meets ISO-16111:2008; IEC 62282 Part 6; or other applicable standards as appropriate or required for the application and targeted usage | ||
| Safety | |||
| Loss of usable H2 h | |||
a The targets are based on the lower heating value of hydrogen, without consideration of the conversion efficiency of the fuel cell power plant. Targets are for the complete hydrogen storage and delivery system, including tank, material, valves, regulators, piping, mounting brackets, insulation, added cooling or heating capacity, and/or other balance-of-plant components. All capacities are defined as usable capacities that could be delivered to the fuel cell power plant during normal use. All targets must be met at the end of service life.
b Generally the 'full' mass (including hydrogen) is used; for systems that gain weight on hydrogen release, the highest mass during discharge is used (e.g., hydrogen release through hydrolysis reaction resulting in the formation of oxides/hydroxides). All capacities are net usable capacity able to be delivered to the fuel cell power plant. Capacities must be met at end of service life.
c "Net useful energy" or "net" excludes unusable energy (i.e., hydrogen left in a tank below minimum fuel cell power plant pressure, flow, and temperature requirements) and hydrogen-derived energy used to extract the hydrogen from the storage medium (e.g., fuel used to heat a material to initiate or sustain hydrogen release).
d Stated ambient temperature plus full solar load (i.e., if exposed to direct sunlight or stored within a container exposed to direct sunlight for extended periods of time). No allowable performance degradation from –20°C to 40°C. Allowable degradation outside these limits is to be determined.
e Delivery temperature refers to the inlet temperature of the hydrogen to the fuel cell.
f The external device temperature is the maximum temperature generated at the external surface of the hydrogen storage container during operation.
g Hydrogen storage systems must be able to deliver hydrogen meeting acceptable hydrogen quality standards, such as ISO-16111:2008 and IEC 62282 Part 6. Note that some storage technologies may produce contaminants for which effects are unknown and not addressed by the published standards; these will be addressed by system engineering design on a case by case basis as more information becomes available.
h Total hydrogen lost into the environment as H2; relates to hydrogen accumulation in enclosed spaces. Storage system must comply with appropriate standards, such as ISO-16111:2008 and IEC 62282 Part 6. This includes any coating or enclosure that incorporates the envelope of the storage system.