Capstone project completed with Alan Thai and Arthur Yip. Briefly, we describe our MATLAB model for a renewable energy hub consisting of solar panels, wind turbines and an electrolyzer for generating hydrogen. The generated hydrogen was then used to run hydrogen-powered forklifts. The environmental and financial analysis were shown to be sufficient to warrant further investigation.

1. Green Energy Hub
Alan Thai, Jake Yeung, Arthur Yip
Walmart Green Student Challenge
A Novel Design to Address Energy Needs

2. Agenda
• Challenges
• Energy Hub Concept
• Design
• Financial Analysis
• Environmental Benefits
2

3. Growth in Renewables
3

4. Fluctuating Electricity Price
• March 2012 Average Price: $15/MWh
• 9 AM, March 11, 2012: -$128/MWh
4

5. Electric Grid Overload
Excess Supply
Electric Grid Instability
5

6. Energy Hub Design
Green
Energy Hub
• 100% Renewable Electricity
• Clean On-Site Fuel
6
$$$
• Improved Grid Stability
Green
Energy Hub
H2

7. Inside an Energy Hub
7
Grid
Photovoltaics
Turbines LEDs
Chillers
H2
Electrolyzer Forklift Fuel
Solar
Wind Lighting
Refrigeration
Grid
Connection

8. Walmart’s Interest in Our Idea
8

9. Financial Incentives
• Ontario Feed-In Tariff (FIT): $135/MWh for
wind, $530/MWh for solar
• Grid Services worth up to $100 000/yr per
MW of load flexibility
• Savings from on-site hydrogen production
9

10. Methodology
• Technology Screening
• Modeling and Simulation
• Optimization of Design Parameters
• Financial and Environmental Analysis

11. Green Energy Hub Design
H2
Legend Ball
Valve
Check Valve
Pressure
Safety Valve
Vent
H2 Fueling Station
Distribution Centre
Electrolyzer
Electricity
H2
350 bar
Compressor
Wind
Solar
Grid
Hydrogen System
H2O

12. MATLAB Simulation
Loop for all hours in a year
Wind and solar data
Timescales:
All hours
All months
All seasons
Building load,
assuming no peak shifting

13. MATLAB Simulation
Horizontal-axis wind turbines Thin-film CdTe solar panels Alkaline electrolyzer

14. Seasonal Variation
Summer
6AM 12PM 6PM
-2000
-1000
0
1000
2000
3000
Time
Power(kW)
6:00 12:00 18:00
3000
1000
-1000
2000
0
-2000
Time of DayTime of Day
Winter
6AM 12PM 6PM
-2000
-1000
0
1000
2000
3000
Hour of the day
Power(kW)
6:00 12:00 18:00
3000
1000
-1000
2000
0
-2000
Power(kW)

15. Energy Hub Response to Spikes
6AM 12PM 6PM
-2000
-1000
0
1000
2000
3000
Time
Power(kW)
6:00 12:00 18:00
3000
1000
-1000
2000
0
-2000
6AM 12PM 6PM
-2000
-1000
0
1000
2000
3000
Time
Power(kW)
Wind and Solar Power Spikes
Smoothing Fluctuations
6:00 12:00 18:00
Time of Day
3000
1000
-1000
2000
0
-2000
Power(kW)

16. Optimization of Wind and Solar
Identification of optimal combination of wind and solar power to
meet the goal of net 100% renewable power
Capacity (MW) Net Renewable
(% of load)
Net Grid Reliance
(% of load)Solar Wind
3 9 87% 30%
3 10.5 95% 28%
4 9 100% 28%
4 10.5 108% 25%

17. Optimization of Electrolyzer
Identification of optimum size of electrolyzer by potential value of
savings from on-site H2 and revenue from grid service
Electrolyzer
Model
Capacity
(kW)
Capital Cost
(CAD$)
Annual Return
(CAD$)
IRR
(%)
HySTAT-45 235 $ 800,000 $ 195,000 32%
HySTAT-60 312 $ 900,000 $ 216,000 32%
2 x HySTAT-45 470 $ 1,200,000 $ 260,000 27%
2 x HySTAT-60 624 $ 1,400,000 $ 303,000 27%

18. Final Design Specifications
18
Grid
Photovoltaics
Turbines LEDs
Chillers
Electrolyzer Forklift Fuel
Solar
Wind Lighting
Refrigeration
Grid
Connection
6 x 1.5 MW
4 MW
HySTAT-60
312 kW




19. Financial Analysis
Solar FIT
Contract,
$3.10 M
Wind FIT
Contract,
$1.33 M
Hydrogen
System,
$1.32 M
Grid Services,
$1.27 M

20. 0
50
100
150
0 5 10 15 20
$Millions(CAD)
Project lifetime (years)
Break-Even Analysis

21. Environmental Benefits
21
State-of-
the-Art
Facility
Green
Energy
Hub0
500
1000
1500
AnnualCO2Emissions
(tonnesCO2/yr)
CO₂ from Hydrogen
Production
CO₂ from Building
Operations

22. 22
71% CO2
Reduction
Investing in
the Future
Leadership
in Energy
Green Energy Hub
Integration of technologies to address energy holistically

23. Future Work
• Investigation into alternative uses of spare hydrogen
capacity, including stationary fuel cell power, fuel
cell vehicles, and industrial usage of H2, O2, and
waste heat
• Detailed control system design to collect and
redistribute power depending on weather, price
signals, and operational needs
• Stochastic optimization of parameters to minimize
cost and maximize benefits such as environmental
impact reduction
23

24. Acknowledgements
• Kevin Brant
• Michel Archambault
• Greg Ponesse
• Dr. Michael Fowler
• Faraz Syed
• Dr. Marc Aucoin 24

25. 25