Description of hydrogen energy storage options for intermittent renewable sources. Presented to Russian Academy of Sciences - US DOE International Seminar on Fuel Cell Technology, Oct 12-14, 1999

1. Remote Renewable Fuel Cell Systems
DOE-Russian Academy of Sciences Workshop
on
The Science Behind Fuel Cell Technology
Moscow, Russia
October 12-14, 1999
Glenn D. Rambach
Energy and Environmental Engineering Center
Desert Research Institute
Reno, NV
http://www.dri.edu
desert
research
institute
University and Community College
System of Nevada

2. Glenn Rambach Fuel Cells in Remote Applications Desert Research Institute
The science requirements for assuring the implementation of fuel cells in remote applications In Russia In The United States In ROW status of the technology today expected performance and cost evolution

3. • Hydrogen as a utility energy storage medium.
 To buffer the intermittency and phase differences of renewables an loads.
 Permits full autonomy from a fossil fuel supply infrastructure.
 The storage function of hydrogen systems is more complex than, either
battery storage systems or fossil fueled fuel cell systems.
 Batteries have one power/energy element.
 Fossil fuel cell system have two power elements and a simple energy
element.
 Four separate power or energy elements permit optimization in H2 system.
 Models are yet to be developed for optimization of design and control of a
hydrogen system.
 DRI is developing these models and relating them to current models for
similar systems.
 To test these and other models, DRI has a complete 5-kW scale research
system with wind, solar, fuel cell stack, electrolyzer, storage tank,
programmable load, computer control and data acquisition system.
Approach/Rationale

4. Intermittent renewable electricity
Liquid
fossil fuel
Reformer and purifier
Electrolyzer
Hydrogen
Storage
Fuel cell PEM SOFC PAFC MCFC AFC
Local grid
Remote load
Fuel Cell Utility Power Systems Configuration options
Delivered
Hydrogen
- OR -
- OR -
Hydrogen
Electrical power

5. Wind, hydrogen, fuel cell isolated power system
Cogen heat

6. • Wind turbine
• Solar PV
• Micro-hydro
• Low-q water turbine
• Wind
• Sunlight
• Water flow
Power logic
controller
• Community
• Mine
• Military post
• Autonomous device
• Hydrogen-fuel cell
• Hydrogen-ICE gen
• Halogen fuel cell
• Zn-Air fuel cell
• Zn-FeCN fuel cell
• Flywheel
• Compressed air
• Pumped hydro
• Battery
• Grid
Nature
Customer
Source, process, storage and load options
Energy
Storage
time
dependant
source
time
dependant
load

7. • Wind turbine
• Solar PV
• Low-q water turbine
• Wind
• Sunlight
• Water flow
Power logic
controller
• Community
• Mine
• Military post
• Autonomous device
Source, process, storage and load options
- How to use them -
• m Hydro
Characterize complex
source/load profiles
Create and use algorithm to design optimum system
based on current technology and source/load profiles
Create and use algorithm to
operate system to provide least
costly electricity to customer
• Hydrogen-fuel cell
• Hydrogen-ICE gen
• Halogen fuel cell
• Zn-Air fuel cell
• Zn-FeCN fuel cell
• Flywheel
• Compressed air
• Pumped hydro
• Battery
• Grid
Nature
Customer

8. Es = f(Qmax, Pload-avg) DEs = f(hf/c, vehicles) Ps = f(Costvessel, site space)
Power logic controller
Compressor (if needed)
Hydrogen storage
Fuel cell
Cogenerated heat
Intermittent load
Intermittent, renewable source
Design criteria for remote hydrogen fuel cell utility power system
HC = f(hf/c, DCf/c)
Pf/c = f(Pload-peak, Eelec. Stor)
QC = f(QEH2) PC-out = f(Ps) PC-in = f(PEH2-Out)


PRen = f(Pload-peak, hf/c, hEH2, hComp, CFRen, P(t)Ren, CostRen )
P(t)load = f(COE(t), User)
PEH2 = f(Pload-peak, PRen) PEH2-out = f(CostEH2 , TypeEH2)
CostPLC = f(PThru-peak)
Customer
Nature
Electrolyzer

9. DRI residential scale, renewable hydrogen,
fuel cell test facility and refuel station
Computer
and
Power
Logic
Controller
Electrolyzer
5 kW
Computer
Controlled
Load
0 - 5kW
Wind turbines
1.5 kW each
Solar arrays and trackers
1.0 kW each
Fuel cell
2 kW PEM
Hydrogen
Storage
250 psi
Hydrogen
Dispensing
Electricity
Hydrogen

10. PE = PR =
(1 - CfR) PlAV
CfR hE hFC hC
PE = Electrolyzer rated power PR = Renewable peak capacity PlAV = Average load power Cf = Capacity factor h = Efficiency (<1) FC = Fuel cell system C = Compressor
Relationship of load, capacity factor, efficiencies to the power of renewable and electrolyzer

11. Effects of renewable capacity factor, electrolyzer
efficiency and fuel cell system efficiency on renewable
power and electrolyzer power needed
Load average is 100kW
hE = Electrolyzer efficiency
hFC = Fuel cell power system efficiency
.70
.65
.70
.75
.70
.75
.40
.54
.40
.55
.55
.40
hFC
hE

12. Effects of renewable capacity factor and
turn-around efficiency on renewable power
and electrolyzer power needed
Load average is 100kW
.30
.25
.40
.35
.45
.50
.60
.70
hTurn-around

13. DRI residential scale, renewable hydrogen, fuel cell test facility and refuel station
Computer
and
Power
Logic
Controller
Electrolyzer 5 kW
Computer Controlled Load 0 - 5kW
Wind turbines 1.5 kW each
Solar arrays and trackers 1.0 kW each
Fuel cell 2 kW PEM
Hydrogen Storage 150 psi
Hydrogen Dispensing
Electricity
Hydrogen

14. 2 kW PEM Fuel Cell
Two 1.5 kW Wind Turbines
Two 1 kW Solar Arrays
Hydrogen Generator
Planned Hydrogen Fuel Cell Vehicle
Hydrogen Refueling Station
Hydrogen
Storage
Tank
Components of DRI renewable hydrogen, fuel cell test facility

15. Renewable Hydrogen Energy Research System at DRI

16. Wind turbines
1.5 kW each
PV arrays
1.0 kW each
Wind and Solar at DRI Northern Nevada Science Center

17. Fuel cell system
and inverter
Switch
Out
Water recycling
Condenser
KOTZ
Radio
Transmitter
Three
miles
11-MW Diesel
Power Plant
Proportional
Power
KEA Wind Farm (650 kWp)
Village of Kotzebue
Wind, hydrogen, fuel cell power for KOTZ Radio Transmitter
One of two design options in Kotzebue, AK
DRI Project
addition
Diesel-to-hydrogen
reformer
Diesel fuel

18. PEM fuel cell systems
and inverters
Switch
Out
Three
miles
11-MW Diesel
Power Plant
Wind
Power
KEA Wind Farm (650 kWp)
Village of Kotzebue
Wind, hydrogen, fuel cell power system for Kotzebue, Alaska
Three
miles
Hydrogen transmission line
250-psig, 1/2” Dia.
Switch
Out
100% penetration wind turbine modifications
DRI Project
addition
Excess
Wind
Power
Water storage
Hydrogen storage
Diesel-to-hydrogen
reformer
Diesel fuel

19. Anchorage
Fairbanks
Nome
Kotzebue
Wales
Kivalina
Deering
St. George
Seward
Juneau
St. Paul
Kotzebue, Alaska wind turbine site
650 kW of
wind power
in 10 wind
turbines

20. Market entry opportunities for fuel cells
- Find the beginning, start there -
Unit power cost vs. unit size
Two-cycle scooter
and small application
0.01
Portable diesel
generator replacements
(Large)
PEMFCs
Today
(Small)
Residential fuel cell
battery hybrid
(EPRI MON)
Residential
direct power
production
Stationary
utility
production
Range-extended
electric utility vehicle
Electric
wheelchair
Start
here
Finish
here
Less Difficult (cost tolerant market)
Unit power cost ($/kW)
Unit size (kW)
Less Difficult (smaller units)

21. DRI-Nevada Electric Vehicle and Fuel Cell Research Platform
Manufacturer: Coval Partners Sponsor: Nevada State Energy Office

22. DRI Hydrogen Fuel Cell Powered Electric Scooter
Hydride fuel tanks

23. Scooter fuel cell power system components
PEM stack and heat exchanger
Power system control computer
Supercapacitors and batteries
Supercapacitors

24. Charger/Power
logic control
Batteries
Drive
Recharge Motor
power
input
Battery
recharge
power
On-demand
traction electric
power
Traction
electric
power
Battery electric vehicle
• Can be zero emission vehicle
•Large amount of battery energy storage
• Range from energy stored in batteries is limited
• Tradeoff in traction power needed vs. energy storage
• Long recharging time
Hotel
load
Low power electric
High power electric

25. Refuel
input
Hydrogen
supply
Fuel cell
Power logic
control
Batteries
Drive
Motor
Fuel to
cell
Battery
recharge
power
Battery
recharge
power
On-demand
traction electric
power
Traction
electric
power
Fuel cell vehicle - range extender design
• Low power fuel cell used to continuously
recharge batteries
• Large amount of battery energy storage
• Range comes from size of hydrogen supply
• Greater range per mass than batteries
• Batteries currently cheaper per unit power than fuel
cells
• Provide almost all power to motor
• Short refueling time - a few minutes for hydrogen
refueling, compared to several hours for batteries.
Hotel
load
Gas line
Low power electric
High power electric

26. Refuel input
Hydrogen supply
Fuel cell
Power logic control
Battery or supercapacitor
Drive Motor
Gas line
Low power electric
High power electric
Fuel to cell
Traction power
Battery recharge power
On-demand traction electric power
Traction electric power
Fuel cell vehicle - direct fuel cell power design
• All traction power is produced in fuel cell
• Little or no battery energy storage (for fuel cell delay)
• Range comes from size of hydrogen supply
• Greater range per mass than batteries
• Rational approach after fuel cell cost competes with batteries on $/kW scale.
• Short refueling time - a few minutes for hydrogen refueling, compared to several hours for batteries.
Hotel load