Development of Regenerative Fuel Cell Systems for Space Applications
Manuel Hempel NTNU Hydrogen workshop, 03.12.2019, Trondheim
About Prototech
• Established: 1988
• Owner: NORCE (100%)
• Employees: 40
Maritime Renewable Energy Space Environment
Energy supply for Space Applications
• 99% of all spacecraft are powered by photovoltaic
• Nuclear power becomes dominant beyond Jupiter orbit
• Most missions require energy storage for eclipse periods
• Batteries are baseline for storage
• Battery energy density is too low for certain mission scenarios
• RFCS have the potential to achieve higher energy densities than current battery based systems
Equinox
RFCS in general
• Energy Storage System
• Possible alternative to batteries
• Suitable for high power applications
• Main advantage – Potentially higher energy and power
densities achievable
– Enabling Technology for high power missions
– Synergies with other SC subsystems
• Main disadvantage – Lower TRL
– Increased complexity
Electrolyser
Fuel Cell
H2 O2 H2O
RFCS in more detail and RFCS challenges for space
Loops • Green: cooling loop • Red: hydrogen loop • Light blue: oxygen loop • Dark blue: water loop
Redundancy
no redundancy
redundancy
RFCS technology development at Prototech
“Demonstration of a closed loop H2/O2 RFCS” (2009 – 2012)
• In-house made liquid-cooled HTPEM FC stack
• PEM ELY (semi-commercial)
• 1 kW-class FC and ELY
• Closed loop RFCS
• Active gas circulation through FC stack
• Commercial BoP components
• 1350 charge – discharge cycles performed
• Degradation of 0.0018 V/cycle @ 0.133 A cm-2
• 1 kW
• 180 – 200 °C
• 0 - 10 bar
• 91 cm2
• 34 cells
• 0 – 40 A
• Aim: 1 kW/kg
• Liquid cooling
• Thin metal plates
• 4.2 kW (1kW short)
• 80 °C
• 100 bar (O2 & H2)
• 126 cm2
• 33 cells (7cell short)
• 1.75 V/cell @ 1 A cm-2 @ 100 bar
• 0.85 kW/kg
HT PEMFC SPACE STACK HP PEMELY
Prototechs Stack Development
Challenges in Space
Environment • -170 -> 120°C • Radiation • Micro- g • Fractional- g • Launch
• Multi-g • Vibration • Shock loads
Phase separation • No inherent phase
separation in zero- g • Problem in tanks,
separators, sensors etc. • Gravity independent
technologies required
Heat Management • No convection • Complicated thermal
management • Waste heat needs to
be radiated to space
Reliability • 15 years lifetime • No maintenance • No purge
possibility • Reduncancies->
system complexity
Energy storage for space, Moon and Mars: outlook
O2 H2
H2O
H2
O2
Life Support System
Propulsion System
Energy System
In-Situ Resource Utilisation
RFCS H2O
H2O
O2 O2
H2
H2 O2
power
Regolith
CO2
(Mars)
O2
H2O
food
H2O
CO2
FC ELY
RFCS technology development at Prototech
• Projects spanning 2006 - present
• Financed through the European Space Agency
• Development and demonstration of stacks (FC, ELY), RFCS and H2 storage systems:
• “Hydrogen Storage Technologies” • “Regenerative H2/O2 Fuel Cell” • “Innovative Gas Storage on Satellites” • “Advanced Energy Storage System” • “Demonstration of a closed loop H2/O2 RFCS” • “Metal Hydride Hydrogen & Heat Storage System” • “Water Propulsion System” • “Regenerative Fuel Cell Systems Technologies
Development” • “Alternative Energy Storage Solutions for Lunar Night
Survival in Human Exploration Scenarios”
RFCS in 3 scenarios - Environment
HAPS • Gravity
• Low pressure
• 14 h sunlight, 10 h darkness
• - 50 °C
GeoSat • Micro-g
• Vacuum
• Max 72 min darkness
• - 170° - +120°C
Lunar Exploration • Fractional-g, micro-g
• Vacuum
• 14 days sunlight /darkness
• -173° - + 127°C
RFCS in 3 scenarios - Specifications
HAPS • 500 kWh
• 50 kW
• 365 – 1825 cycles
• PEM FC, PEM ELY
GeoSat • 47 kWh
• 30 kW
• 1350 cycles
• HTPEM FC, PEM ELY
Lunar Exploration • 20 kWh
• < 1 kW
• 2 cycles
• PEM FC, PEM ELY
Conclusions, current and future work
• Current space certified batteries (100-170 Wh/kg) have too low energy densities for certain future mission scenarios
• RFCS have the potential to achieve the required energy densities
• Synergies with other SC subsystems are key for flight application
• Current bottleneck: availability of light weight high pressure (100+ bar) gas tanks
• Space trends: – Pump-free systems(higher reliability, less vibration): Passive Cooling, Dead end stack operation
– Phase separation based on membranes
– Cathode vapour feed ELY stacks are being investigated for space applications
HERACLES mission
• Human-Enhanced Robotic Architecture and Capabilities for Lunar Exploration and Science
• Led by ESA in collaboration with JAXA and CSA
• Demonstration robotic mission to evolve into a future human mission
• To land on the far side of the Moon near Lunar south pole (Schroedinger crater) in 2026, deploy a long-range rover, collect 15 kg of samples and deliver to the “Gateway” station, from which astronauts take the samples to Earth using Orion infrastructure
HERACLES
Getaway, HERACLES and Orion
Applications of RFCS on the Moon
Manned rover • 1700 kWh
• 5 kW
Lunar base • 17 MWh
• 50 kW
Robotic exploration • 20 kWh
• 200 W
Top Related