cordero 6 a

Modeling and Simulation for Power Systems

Salvador Cordero, MSSE

Regional Cyber and Energy Security Center

[email protected]

915-747-5206

18 October 2012

Re-Energize the Americas Conference

mailto:[email protected]

2Copyright @ The University of Texas at El Paso. Proprietary Information

Topics

• Why Modeling & Simulation?

• Modeling & Simulation Tasks

• Modeling Tool Parameters

• Case Study

• Solar PV System

• Microgrid System

• Summary


Why Modeling & Simulation?


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.


Modeling Tool Parameters

Inputs

Loads,

Components, Grid

Tie

Utility Rate

Structure

Economics, System

Control, Emissions,

Controls

Component

Parameters

Costs

HOMER

Performance

Model

Financial Model

Sensitivity Analysis

Results

Financial Metrics:

LCOE, IRR, NPV,

Payback, etc.

Performance

Metrics:

Capacity Factor,

Annual Output

Other:

Energy flows, Cash

flows, Graphs

*National Renewable

Energy Laboratory (NREL)


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


Case Study: Load Profiles

*Electric Utility 30 minute meter readings Main Campus

Physical Plants


Case Study: Load Profiles

Thermal Load


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


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

Capital Cost-$12,864,280$ 3.80 per watt ( Panels & Inverters)

Capital Cost-$20,900,000$ 3.80 per watt ( Panels & Inverters)

*SUNPOWER T10 Solar Roof Tile



7,250KW

2,130KW

7,250KW

3,825KW

3.38 MW PV System 5.50 MW PV System

52.8% of Peak Load 29.4% of Peak Load



• Annual Electrical Production

1. Baseline 0 kWh

2. 3.38 MW PV System 6,236,530 kWh

3. 5.50 MW PV System 10,139,876 kWh

• Annual Grid Purchases

1. Baseline 46,880,920 kWh

2. 3.38 MW PV System 40,644,392 kWh

3. 5.50 MW PV System 36,929,608 kWh

kWh’s

Saved

22%

Reduction

13%

Reduction



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



Savings $416,701 $479,209 $541,714

ROI -2.8% 11.7% 26.3%

5.50 MW System



Savings $676,736 $778,250 $879,760

ROI -3.0% 11.5% 26.1%


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)



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

• Efficiency- 83.7%

• Heat recovery- 75%

• Cost- $20,741,284

• Energy Storage System

• Capacity- 1 MWh

• Voltage- 12 V

• Round trip efficiency- 90%

• Cost- $1,000,000

• Total Investment Cost = $42,641,284

*SUNPOWER T10 Solar Roof Tile

*Solar Turbines Centaur 70

*Xtreme Power DPR


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


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.


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


Questions

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