1. Modeling and Simulation for Power Systems
Salvador Cordero, MSSE
Regional Cyber and Energy Security Center
rces@utep.edu
915-747-5206
18 October 2012
Re-Energize the Americas Conference

2. Topics
• Why Modeling & Simulation?
• Modeling & Simulation Tasks
• Modeling Tool Parameters
• Case Study
• Solar PV System
• Microgrid System
• Summary
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3. Why Modeling & Simulation?
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4. Modeling & Simulation Tasks
• Task 1: Modeling and Prediction of Baseline Energy Consumption.
– Discover and quantify the energy consumption so that power system models can
be developed for renewable energy sources, integration to current infrastructure,
and deployment.
– Discover the “As-Is” Energy System
– Validate the models using measurement data
• Task 2: Analysis for Co-generation and Renewable Energy
Penetration
– Evaluate performance model for the co-generation and renewable energy
integration.
– Combine the models for energy consumption and cost, and add cost benefit
analysis model. The combined model allows the effects of renewable energy and
co-generation installments to be studied from a performance and cost viewpoint
– Develop a common template for evaluating different technologies.
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5. Modeling Tool Parameters
Inputs Results
Loads, Financial Metrics:
Components, Grid LCOE, IRR, NPV,
Tie Payback, etc.
HOMER
Utility Rate *National Renewable
Performance
Structure Energy Laboratory (NREL)
Metrics:
Performance Capacity Factor,
Component Model Annual Output
Parameters
Financial Model Other:
Costs Energy flows, Cash
Sensitivity Analysis flows, Graphs
Economics, System
Control, Emissions,
Controls
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6. Case Study: Model Inputs
Main Campus and Physical Plants
• Project Lifetime
• 30 Years
• Annual Interest Rate
• 2%
• Natural Gas Cost
• $5.00/Mcf based on Facilities’ billing
adjustment credits with supplier
• Combined Rate Schedule
• Current electric rate for Physical Plants
• Current rate was considered for Main Campus
• Blended flat rate for both loads (includes fuel adjustment)
1. Current is at 6.5¢/kWh
2. 15% increase at 7.4¢/kWh
3. 30% increase at 8.5¢/kWh
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7. Case Study: Load Profiles
Physical Plants
*Electric Utility 30 minute meter readings Main Campus
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8. Case Study: Load Profiles
Thermal Load
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9. Case Study: Baseline Model Results
Main Campus & Physical Plants
• Annual Electric Consumption of 62,619,500 kWh/yr
• Annual Gas Consumption of 52,333,392 kWh/yr = 176,546 MMBtu
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10. Case Study: Solar PV System
• One load: Main Campus
• Flat rate structure
• Sensitivity Analysis on cost of Electricity (Current, 15%, 30% Increases)
• Grid Tie Connection
• Two Scenarios:
1. Baseline with 3.3 MW Solar PV
2. Baseline with 5.5 MW Solar PV
• Solar PV System Specifications:
3.38 MW 5.5 MW
Micro-Inverter(95.5% efficiency)
10 Degree Tilt
85% De-rating Factor
30 yr. Lifetime *SUNPOWER T10 Solar Roof Tile
Capital Cost-$12,864,280 Capital Cost-$20,900,000
$ 3.80 per watt ( Panels & Inverters) $ 3.80 per watt ( Panels & Inverters)
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11. Case Study: Solar PV System
3.38 MW PV System 5.50 MW PV System
7,250KW 7,250KW
3,825KW
2,130KW
29.4% of Peak Load 52.8% of Peak Load
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12. Case Study: Solar PV System
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13. Case Study: Solar PV System
• Annual Electrical Production
1. Baseline 0 kWh
2. 3.38 MW PV System 6,236,530 kWh
kWh’s
3. 5.50 MW PV System 10,139,876 kWh Saved
• Annual Grid Purchases
1. Baseline 46,880,920 kWh
13%
2. 3.38 MW PV System 40,644,392 kWh Reduction
3. 5.50 MW PV System 36,929,608 kWh
22%
Reduction
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14. Case Study: Solar PV System
Current Rate 15% Increase 30% Increase
Main Campus Baseline
Cost of Electricity $3,261,809 $3,751,083 $4,240,354
LCOE 7.0¢/kWh 8.1¢/kWh 9.1¢/kWh
3.38 MW System
Cost of Electricity $2,845,108 $3,271,874 $3,698,640
LCOE 7.3¢/kWh 8.2¢/kWh 9.1¢/kWh
Savings $416,701 $479,209 $541,714
ROI -2.8% 11.7% 26.3%
5.50 MW System
Cost of Electricity $2,585,073 $2,972,833 $3,360,594
LCOE 7.6¢/kWh 8.4¢/kWh 9.1¢/kWh
Savings $676,736 $778,250 $879,760
ROI -3.0% 11.5% 26.1%
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15. Case Study: Microgrid System
Assumptions:
• Two electrical loads: Main Campus and
Physical Plants
• One thermal load
• Constant cost for Natural Gas
• No Grid Tie Connection
• Self-Generation
• 5.5 MW PV System
• CHP System with two 7.5 MW Turbines
• Energy Storage System (1 MWh)
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16. Case Study: Microgrid System
Component Specifications:
• Solar PV System
• Size- 5.5 MW
• Derating factor- 82%
• Cost- $20,900,000
• CHP System
• Size- Two 7.5 MW turbine generators *SUNPOWER T10 Solar Roof Tile
• Efficiency- 83.7%
• Heat recovery- 75%
• Cost- $20,741,284
• Energy Storage System
• Capacity- 1 MWh
• Voltage- 12 V *Solar Turbines Centaur 70
• Round trip efficiency- 90%
• Cost- $1,000,000
• Total Investment Cost = $42,641,284 *Xtreme Power DPR
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17. Case Study: Microgrid System
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18. Facility Case Study: Microgrid System
Current Rate 15% Increase 30% Increase
Baseline for Combined Loads
Cost of Electricity (Annual) $4,070,259 $4,633,833 $5,322,647
Cost of Gas (Annual) $1,001,033 $1,001,033 $1,001,033
LCOE 6.5¢/kWh 7.4¢/kWh 8.5¢/kWh
Total Utility Cost (Annual) $5,071,292 $5,756,367 $6,382,561
Microgrid System
LCOE 7.7¢/kWh
Total Operating Cost $3,942,864/yr.
Savings $1,128,428 $1,813,503 $2,439,697
ROI -21% 28% 72%
*ROI based on initial investment of $42,641,284 and only 30 year lifecycle.
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19. Summary: Case Study
Integrating energy resources into a comprehensive management strategy
can optimize energy security and system reliability to avoid grid standby
charges and/or outages.
• Solar PV reduces peak demand and yearly operating costs
• Multiple units will provide power generation redundancy to improve reliability and avoid
electric rate stand-by charges.
• Multiple units reduces individual operational running times which extend system’s
lifetime and provides maintenance flexibility.
• Hybrid co-generation of Solar PV and gas turbines provide load balancing capability
to a micro-grid:
o Co-generation backs up the solar PV systems during periods of intermittency to
avoid grid demand charges
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20. Questions
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