The energy industry is rapidly evolving to take advantage of renewable resources and Western Power is embracing new technologies that will improve service and reliability to our customers. New and improving technologies such as solar, wind, wave and most importantly batteries are changing the way we think about the delivery and storage of electricity. One of these developments is the microgrid, which is essentially a small scale power grid that can operate independently (in ‘island mode’) or connect with the main electrical grid – think of a small suburb, or estate, that shares electricity and the cost of the infrastructure. A microgrid needs to control the flow of electricity of low or medium voltage, but does not need connection to a centralised generation or transmission network. Western Power has trialled the world’s first microgrid project that combines wave energy, solar (photovoltaic) energy, a desalination plant, and energy storage that connects to our large electricity network. Thair demonstrates extensive engineering experience focused on power systems planning and real-time operation. This includes experience in load, generation and microgrids grid connection, renewable energies, transmission networks planning and stability. This experience is supported by his academic research at the University of Tasmania and Edith Cowan University, including invitation to review international journals and conferences in the field of Energy Systems and Artificial Intelligence. Thair has previously held roles with Canegie Wave Energy and Deng Kai.

1. Thair Mahmoud
Optimal sizing of Battery Energy
Storage Systems in microgrids

2. State Government-owned corporation that builds,
maintains and operates electricity network throughout
majority of south Western Australia
Governed by an independent Board and reports to Minister
for Energy, as owner’s representative
Serving more than one million customers across a network
area of 254,920 km2
Customer-orientated organisation that provides a safe, reliable
and affordable electricity supply to Western Australians
Provides an essential service through transmission and
distribution of electricity across our vast infrastructure of
poles, wires, substations and depots
2

3. Source: CSIRO
Possible future scenarios for Australia’s
electricity network
3

4. What are microgrids?
4
Source: CleanTechnica

5. Garden Island Microgrid Project

6. Garden Island Microgrid Project

7. Garden Island Microgrid Project

8. Garden Island Microgrid Project

9. Garden Island Microgrid Project
Source: Carnegie Wave Energy

10. Garden Island Microgrid Project

11. Challenges – BESS sizing in microgrids
Key microgrids BESS sizing elements
11
Role
Why the
microgrid
solution is
needed?
Location
Regulations and
grid rules
Control Level
Communication
and Intelligence
Placement
Network
situation
Source: Microgrid Knowledge

12. Another microgrid case study
Load and generation profiles
– 2800 kW load
– 250 kW wind
– 900 kW solar PV
– 3000 kW diesel
(6x 500 kW)
12

13. Microgrid generation cost
Required knowledge
– Cost analysis
– Controller behaviour
– Load and generation
profiles
13

14. Sizing process
14
Simulate
Micro grid
operation
scenarios
Simulate
Micro grid
operation
scenarios
Evaluate
annual
energy
cost (kWh)
Evaluate
annual
energy
cost (kWh)
Nominate
size
Nominate
size
Load
12 months
data
Load
12 months
data
Forecasts
- Load profile
- Generation
profile
- Fuel price
Operation rules
Battery SOC & RTED
Constraints (Thermal,
Stability, Fault
contribution & Generation
Capabilities
Change size subject to
- Transformer size
- DC and AC bus size
- Inverter specs.
- Battery string size
- Installation space
0
1000
2000
3000
1
248
495
742
989
1236
kW
30 Min intervals
5000000
5200000
5400000
5600000
5800000
1 11 21
Cost($)
BESS Size X 100 kVA

15. Simulation results - scenarios
15
Source: APISource: Synergy

16. Simulation results - scenarios
16

17. Intelligent microgrid generation price monitoring
MGC
performs
economic
dispatch
MGC
performs
economic
dispatch
BESS SOC
performance
monitoring
BESS SOC
performance
monitoring
Load
12
months
data
Load
12
months
data
17
Forecasts
- Load profile
- Generation
profile
- Fuel price
Operation rules
Battery SOC & RTED
Constraints (Thermal,
Stability, Fault
contribution &
Generation Capabilities)
Adapt charging price for
BESS from diesel/utility
based on the weekly price
change trends
Microgrid
generators
dispatch

18. Artificial Intelligence in microgrids control
Optimal generation in microgrids
18
Machine Learning
Forecasting and
trends monitoring
Rule-based expert
systems
Rules for battery
charge/discharge
time and price
Linear-
programming
Generation
scheduling and
economic dispatch

19. Simulation results - scenarios
19

20. Conclusion- BESS sizing problem
Required size
– To achieve operation requirements
Optional size
– To reduce operation cost
Optimal size
– Best combination of the
fixed and variable size
20
+ -
+ -
Optimal
VariableFixed

21. Conclusion - BESS sizing problem
The size of BESS can be decided by the technical
operation requirements
Intelligent operation of BESS can reduce the operation
cost of microgrids
The optimal sizing can be decided based on the network
planning studies and economic analysis
The location of microgrids can significantly affect sizing
21

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