Use of PLEXOS in Economic Engine Dispatch · •Operated by BELCO system operators, managed by system reliability. Economic Dispatch –Initial Model •Model Limitations •Low ability

Use of PLEXOS in Economic Engine Dispatch

Donald Marwick

Plant Performance Engineer

BELCO

Introduction

• Overview

• Development of Economic Dispatch

• The Move to PLEXOS

• PLEXOS Dispatch Modeling

• Impact of PLEXOX based economic dispatch

• Development of Automated Dispatch Modeling

Overview

• BELCO• Bermuda Electric Utility

• 1904

• 153MW of Generation Capacity• 8 Diesel Engines (HFO)

• 4 Diesel Engines (LFO)

• 4 Gas Turbines (LFO)

• 2018 Peak Load of 103.8MW

• 2018 Total Generation 629.3GWh

• 38,013 Total Connections

Overview

• Bermuda• 20.54 square miles

• Atlantic Island 665 miles East of North Carolina

• No Energy Market

• 4.7MW Government Waste to Energy

• Small amount of distributed rooftop solar power

• Electric generation and distribution handled by utility

Economic Dispatch

• BELCO operated on a traditional utility model

• Operational focus on system stability

• Rise in oil prices increased in the 2010s

• This placed a higher priority of fuel efficiency

Economic Dispatch

Source: macrotrends.net

Economic Dispatch

• BELCO operates with a fuel adjustment• Utility carries the cost of the first $30/bbl

• The remainder is passed onto the customer

• Lack of energy market requires extensive use of peaking units in summer months

• Leads to a significantly higher fuel adjustment in summer

• Key priority for economic dispatch

Economic Dispatch – Initial Model

• Initial Model Developed using Excel• Dynamic Economic Dispatch Model

• Calculated optimal load distribution based on engine curves using iterative calculations

• Tied into plant data to provide continuous dispatch instructions

• Operated by BELCO system operators, managed by system reliability


• Model Limitations• Low ability to account for system constraints

• Changes to the model required extensive rebuilding of the Excel file

• Concerns regarding dispatch instructions• Too aggressive

• Increased maintenance costs

• Benefits not clear to operators

• Use of the model was discontinued in the summer of 2012


• Used in backcasting and cost of engine analysis

• Adapted for use in capital planning• Compared optimum dispatch for proposed engines

• Used in support of Integrated Resource Plan

• Expanded to include additional factors• Fuel types

• Alternate engine types

• Load projections

• Levels of solar penetration

• Multiple 20 year models run in Excel

Move to PLEXOS

• Limitations of Excel modeling became clear

• Additional work would require extensive internal development or the selection of a dedicated modeling software

• Selection process lead to the use of PLEXOS for BELCO’s modeling solution

Move to PLEXOS

• PLEXOS was an extremely robust option for BELCO• No energy market

• All dispatchable generation at centralized location

• Plant expansion generally runs on a 20 year cycle

• PLEXOS advantages• Easy transfer of existing modeling work

• Future proof against changes in energy landscape• Utility scale solar

• Distributed generation

• 3rd party generators

Move to PLEXOS

• Began modeling with PLEXOS in 2015

• Was able to complete system model during initial visit

• Initial work in support of capital expansion and IRP

• By summer 2015 model was developed with sufficient confidence to resume economic dispatch

PLEXOS Dispatch Modeling

• Dispatch model developed by adapting short term capital assessment model for engine dispatch

• Live data not possible with current model structure

• Developed a ‘Day Ahead’ methodology to provide dispatch instructions for a 24 hour period

• Worked in operation center to ensure successful rollout of dispatch model


• Initial dispatch instructions generated using daily load curves

• Curves from previous day were scaled based on projected peak for coming day

• PLEXOS dispatch was generated based on engine availability and ratings


Datetime Units E1 E2 D10 D3 D8 E4 E5 E7 E8 GT3E GT3F GT4 GT6 GT7 GT8 Total

6/4/2015 9:00 MW 9.87 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 0 4.2 82.17

6/4/2015 9:30 MW 8 10.52 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 82.92

6/4/2015 10:00 MW 8 12.08 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 84.48

6/4/2015 10:30 MW 9.1 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 85.6

6/4/2015 11:00 MW 10.05 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 86.55

6/4/2015 11:30 MW 10.58 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 87.08

6/4/2015 12:00 MW 11.5 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 88

6/4/2015 12:30 MW 11.32 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 87.82

6/4/2015 13:00 MW 10.64 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 87.14

6/4/2015 13:30 MW 10.83 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 87.33

6/4/2015 14:00 MW 10.57 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 87.07

6/4/2015 14:30 MW 8.84 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 85.34

6/4/2015 15:00 MW 8.53 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 85.03

6/4/2015 15:30 MW 8 11.8 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 84.2

6/4/2015 16:00 MW 8 11.02 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 83.42

6/4/2015 16:30 MW 8 11.72 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 84.12

6/4/2015 17:00 MW 8.81 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 85.31

6/4/2015 17:30 MW 8 11.75 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 84.15

6/4/2015 18:00 MW 8 11.56 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 83.96

6/4/2015 18:30 MW 8 11.65 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 84.05

6/4/2015 19:00 MW 8 11.38 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 83.78

6/4/2015 19:30 MW 8 10.25 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 82.65

6/4/2015 20:00 MW 8 10.02 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 82.42

6/4/2015 20:30 MW 9.16 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 0 4.2 81.46

6/4/2015 21:00 MW 9.07 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 0 4.2 81.37

6/4/2015 21:30 MW 10.19 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 0 4.2 82.49

6/4/2015 22:00 MW 8 11.63 3 3 3 8.5 12.5 13 13 0 0 0 0 0 4.2 79.83

6/4/2015 22:30 MW 8.48 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 0 0 76.58

6/4/2015 23:00 MW 8 10 3 3 3 7.777778 12.5 12.23444 12.67778 0 0 0 0 0 0 72.19

6/4/2015 23:30 MW 8 10 3 0 3 7.777778 12.5 11.90444 12.67778 0 0 0 0 0 0 68.86


• This approach had several limitations• Load predictions were often not accurate

• Scaling the curve did not account for weather or weekly variations in load distribution

• Curve shape could vary significantly from one day to the next

• Operators were having to hunt through the total load column to locate the closest applicable dispatch


Datetime Units E1 E2 D10 D3 D8 E4 E5 E7 E8 GT3E GT3F GT4 GT6 GT7 GT8 Total

6/4/2015 9:00 MW 9.87 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 0 4.2 82.17

6/4/2015 9:30 MW 8 10.52 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 82.92

6/4/2015 10:00 MW 8 12.08 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 84.48

6/4/2015 10:30 MW 9.1 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 85.6

6/4/2015 11:00 MW 10.05 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 86.55

6/4/2015 11:30 MW 10.58 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 87.08

6/4/2015 12:00 MW 11.5 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 88

6/4/2015 12:30 MW 11.32 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 87.82

6/4/2015 13:00 MW 10.64 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 87.14

6/4/2015 13:30 MW 10.83 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 87.33

6/4/2015 14:00 MW 10.57 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 87.07

6/4/2015 14:30 MW 8.84 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 85.34

6/4/2015 15:00 MW 8.53 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 85.03

6/4/2015 15:30 MW 8 11.8 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 84.2

6/4/2015 16:00 MW 8 11.02 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 83.42

6/4/2015 16:30 MW 8 11.72 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 84.12

6/4/2015 17:00 MW 8.81 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 85.31

6/4/2015 17:30 MW 8 11.75 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 84.15

6/4/2015 18:00 MW 8 11.56 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 83.96

6/4/2015 18:30 MW 8 11.65 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 84.05

6/4/2015 19:00 MW 8 11.38 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 83.78

6/4/2015 19:30 MW 8 10.25 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 82.65

6/4/2015 20:00 MW 8 10.02 3 3 3 8.5 12.5 13 13 0 0 0 0 4.2 4.2 82.42

6/4/2015 20:30 MW 9.16 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 0 4.2 81.46

6/4/2015 21:00 MW 9.07 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 0 4.2 81.37

6/4/2015 21:30 MW 10.19 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 0 4.2 82.49

6/4/2015 22:00 MW 8 11.63 3 3 3 8.5 12.5 13 13 0 0 0 0 0 4.2 79.83

6/4/2015 22:30 MW 8.48 12.1 3 3 3 8.5 12.5 13 13 0 0 0 0 0 0 76.58

6/4/2015 23:00 MW 8 10 3 3 3 7.777778 12.5 12.23444 12.67778 0 0 0 0 0 0 72.19

6/4/2015 23:30 MW 8 10 3 0 3 7.777778 12.5 11.90444 12.67778 0 0 0 0 0 0 68.86


• Replaced predictive curve with a full load range

• Dispatch generated in half-megawatt increments• Load increasing in 0.5MW increments per time step across

model horizon

• Covered full operational range from minimum load to summer peak


Total Units E1 E2 D10 D3 D8 E4 E5 E7 E8 GT3E GT3F GT4 GT6 GT7

72.0 MW 8 10.00 3.00 4.00 4.00 7.78 12.50 10.50 12.22 0 0 0 0 0

72.5 MW 8 10.00 3.00 4.00 4.00 7.82 12.50 10.50 12.68 0 0 0 0 0

73.0 MW 8 10.00 3.00 4.00 4.00 8.32 12.50 10.50 12.68 0 0 0 0 0

73.5 MW 8 10.00 3.00 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 0

74.0 MW 8 10.50 3.00 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 0

74.5 MW 8.5 10.50 3.00 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 0

75.0 MW 9 10.50 3.00 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 0

75.5 MW 9.5 10.50 3.00 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 0

76.0 MW 10 10.50 3.00 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 0

76.5 MW 10 10.50 3.50 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 0

77.0 MW 10 10.50 4.00 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 0

77.5 MW 10 10.50 4.50 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 0

78.0 MW 10 10.50 5.00 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 0

78.5 MW 8.3 10.50 3.00 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 4.20

79.0 MW 8.8 10.50 3.00 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 4.20

79.5 MW 9.3 10.50 3.00 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 4.20

80.0 MW 9.8 10.50 3.00 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 4.20

80.5 MW 10 10.50 3.30 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 4.20

81.0 MW 10 10.50 3.80 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 4.20

81.5 MW 10 10.50 4.30 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 4.20

82.0 MW 10 10.50 4.80 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 0 4.20

82.5 MW 10 10.50 5.04 4.26 4.00 8.50 12.50 10.50 13.00 0 0 0 0 4.20

83.0 MW 10 10.50 5.04 4.76 4.00 8.50 12.50 10.50 13.00 0 0 0 0 4.20

83.5 MW 10 10.50 5.04 5.26 4.00 8.50 12.50 10.50 13.00 0 0 0 0 4.20

84.0 MW 10 10.50 5.47 5.33 4.00 8.50 12.50 10.50 13.00 0 0 0 0 4.20

84.5 MW 10 10.50 3.10 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 4.20 4.20

85.0 MW 10 10.50 3.60 4.00 4.00 8.50 12.50 10.50 13.00 0 0 0 4.20 4.20


• Benefits of the model still not clearly demonstrated• Operators focused on system stability with plant operations

focused on fuel and maintenance

• Began incorporating the cost of operation into the day ahead tables • Communicated the cost savings of economic dispatch

• Moved away from previous practice of optimizing per unit efficiency


Total E1 E2 D10 D14 D3 D8 E3 E6 E7 E8

72.0 MW 145.96 8.40 150.83 12.10 148.72 3.00 183.04 0 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

72.5 MW 145.99 8.90 150.83 12.10 148.72 3.00 183.04 0 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

73.0 MW 146.02 9.40 150.83 12.10 148.72 3.00 183.04 0 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

73.5 MW 148.05 8.00 150.83 11.00 148.72 3.00 183.04 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

74.0 MW 148.05 8.00 150.83 11.50 148.72 3.00 183.04 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

74.5 MW 148.06 8.00 150.83 12.00 148.72 3.00 183.04 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

75.0 MW 148.07 8.40 150.83 12.10 148.72 3.00 183.04 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

75.5 MW 148.09 8.90 150.83 12.10 148.72 3.00 183.04 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

76.0 MW 148.11 9.40 150.83 12.10 148.72 3.00 183.04 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

76.5 MW 148.13 9.90 150.83 12.10 148.72 3.00 183.04 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

77.0 MW 148.23 10.00 150.83 12.10 148.72 3.40 181.06 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

77.5 MW 148.42 9.90 150.83 12.10 148.72 3.00 183.04 0 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

78.0 MW 148.51 10.00 150.83 12.10 148.72 3.40 181.06 0 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

78.5 MW 148.61 10.00 150.83 12.10 148.72 3.90 178.96 0 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

79.0 MW 148.71 10.00 150.83 12.10 148.72 4.40 177.21 0 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

79.5 MW 148.80 10.00 150.83 12.10 148.72 4.90 175.82 0 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

80.0 MW 150.30 9.40 150.83 12.10 148.72 3.00 183.04 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

80.5 MW 150.30 9.90 150.83 12.10 148.72 3.00 183.04 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

81.0 MW 150.38 10.00 150.83 12.10 148.72 3.40 181.06 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

81.5 MW 150.47 10.00 150.83 12.10 148.72 3.90 178.96 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

82.0 MW 150.55 10.00 150.83 12.10 148.72 4.40 177.21 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

82.5 MW 150.63 10.00 150.83 12.10 148.72 4.90 175.82 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

83.0 MW 150.74 10.00 150.83 12.10 148.72 5.04 175.47 3.00 198.94 4.36 190.27 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

83.5 MW 150.87 10.00 150.83 12.10 148.72 5.04 175.47 3.00 198.94 4.86 188.39 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

84.0 MW 150.99 10.00 150.83 12.10 148.72 5.07 175.42 3.00 198.94 5.33 186.90 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

84.5 MW 151.08 10.00 150.83 12.10 148.72 5.56 174.51 3.00 198.94 5.33 186.90 4.01 176.41 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

85.0 MW 142.91 10.00 150.83 12.10 148.72 3.20 181.99 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

85.5 MW 143.04 10.00 150.83 12.10 148.72 3.70 179.75 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75


Total E1 E2 D10 D14 D3 D8 E3 E6 E7 E8

72.0 MW 145.96 8.40 150.83 12.10 148.72 3.00 183.04 0 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

72.5 MW 145.99 8.90 150.83 12.10 148.72 3.00 183.04 0 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

73.0 MW 146.02 9.40 150.83 12.10 148.72 3.00 183.04 0 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

73.5 MW 148.05 8.00 150.83 11.00 148.72 3.00 183.04 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

74.0 MW 148.05 8.00 150.83 11.50 148.72 3.00 183.04 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

74.5 MW 148.06 8.00 150.83 12.00 148.72 3.00 183.04 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

75.0 MW 148.07 8.40 150.83 12.10 148.72 3.00 183.04 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

75.5 MW 148.09 8.90 150.83 12.10 148.72 3.00 183.04 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

76.0 MW 148.11 9.40 150.83 12.10 148.72 3.00 183.04 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

76.5 MW 148.13 9.90 150.83 12.10 148.72 3.00 183.04 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

77.0 MW 148.23 10.00 150.83 12.10 148.72 3.40 181.06 3.00 198.94 0 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

77.5 MW 148.42 9.90 150.83 12.10 148.72 3.00 183.04 0 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

78.0 MW 148.51 10.00 150.83 12.10 148.72 3.40 181.06 0 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

78.5 MW 148.61 10.00 150.83 12.10 148.72 3.90 178.96 0 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

79.0 MW 148.71 10.00 150.83 12.10 148.72 4.40 177.21 0 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

79.5 MW 148.80 10.00 150.83 12.10 148.72 4.90 175.82 0 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

80.0 MW 150.30 9.40 150.83 12.10 148.72 3.00 183.04 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

80.5 MW 150.30 9.90 150.83 12.10 148.72 3.00 183.04 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

81.0 MW 150.38 10.00 150.83 12.10 148.72 3.40 181.06 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

81.5 MW 150.47 10.00 150.83 12.10 148.72 3.90 178.96 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

82.0 MW 150.55 10.00 150.83 12.10 148.72 4.40 177.21 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

82.5 MW 150.63 10.00 150.83 12.10 148.72 4.90 175.82 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

83.0 MW 150.74 10.00 150.83 12.10 148.72 5.04 175.47 3.00 198.94 4.36 190.27 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

83.5 MW 150.87 10.00 150.83 12.10 148.72 5.04 175.47 3.00 198.94 4.86 188.39 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

84.0 MW 150.99 10.00 150.83 12.10 148.72 5.07 175.42 3.00 198.94 5.33 186.90 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

84.5 MW 151.08 10.00 150.83 12.10 148.72 5.56 174.51 3.00 198.94 5.33 186.90 4.01 176.41 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

85.0 MW 142.91 10.00 150.83 12.10 148.72 3.20 181.99 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75

85.5 MW 143.04 10.00 150.83 12.10 148.72 3.70 179.75 3.00 198.94 4.00 191.84 4.00 176.44 8.00 146.24 13.00 142.43 10.50 137.16 13.00 132.75


• Addressed concerns over system stability

• Custom constraint to keep a fast response turbine in reserve

• Maximum continuous rating on all baseload engine to proven overheat

• Began including system spinning reserve into dispatch instructions


Total Spin E1 E2 D10 D3 D8 E3 E4 E6 E7 E8

72.0 15.4 145.61 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 0 7.78 145.58 12.22 142.60 13.00 136.09 13.00 132.75

72.5 14.9 145.56 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 0 7.82 145.53 12.68 142.42 13.00 136.09 13.00 132.75

73.0 14.4 145.52 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 0 8.00 145.33 13.00 142.43 13.00 136.09 13.00 132.75

73.5 15.4 145.64 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 8.50 146.37 0 13.00 142.43 13.00 136.09 13.00 132.75

74.0 14.9 145.69 8.00 150.83 10.03 148.72 4.00 178.59 0 4.00 176.44 8.97 146.76 0 13.00 142.43 13.00 136.09 13.00 132.75

74.5 14.4 145.72 8.03 150.83 10.50 148.72 4.00 178.59 0 4.00 176.44 8.97 146.76 0 13.00 142.43 13.00 136.09 13.00 132.75

75.0 21.9 146.33 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 5.00 152.48 7.78 145.58 11.06 143.43 12.49 136.04 12.68 132.62

75.5 21.4 146.24 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 5.31 151.26 7.78 145.58 11.06 143.43 12.68 136.01 12.68 132.62

76.0 20.9 146.14 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 5.81 149.59 7.78 145.58 11.06 143.43 12.68 136.01 12.68 132.62

76.5 20.4 146.05 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 6.13 148.68 7.78 145.58 11.23 143.27 12.68 136.01 12.68 132.62

77.0 19.9 145.97 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 6.13 148.68 7.78 145.58 11.73 142.86 12.68 136.01 12.68 132.62

77.5 19.4 145.89 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 6.50 147.84 7.78 145.58 11.87 142.75 12.68 136.01 12.68 132.62

78.0 18.9 145.83 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 6.70 147.43 7.78 145.58 11.87 142.75 12.68 136.01 12.98 132.74

78.5 18.4 145.79 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 6.70 147.43 7.78 145.58 12.02 142.68 13.00 136.09 13.00 132.75

79.0 17.9 145.74 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 6.70 147.43 7.78 145.58 12.52 142.48 13.00 136.09 13.00 132.75

79.5 17.4 145.68 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 6.82 147.24 8.00 145.33 12.68 142.42 13.00 136.09 13.00 132.75

80.0 16.9 145.63 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 7.32 146.57 8.00 145.33 12.68 142.42 13.00 136.09 13.00 132.75

80.5 16.4 145.60 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 7.82 146.23 8.00 145.33 12.68 142.42 13.00 136.09 13.00 132.75

81.0 15.9 145.59 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 8.00 146.24 8.00 145.33 13.00 142.43 13.00 136.09 13.00 132.75

81.5 15.4 145.61 8.00 150.83 10.00 148.72 4.00 178.59 0 4.00 176.44 8.50 146.37 8.00 145.33 13.00 142.43 13.00 136.09 13.00 132.75

82.0 14.9 145.66 8.00 150.83 10.03 148.72 4.00 178.59 0 4.00 176.44 8.97 146.76 8.00 145.33 13.00 142.43 13.00 136.09 13.00 132.75

82.5 14.4 145.68 8.03 150.83 10.50 148.72 4.00 178.59 0 4.00 176.44 8.97 146.76 8.00 145.33 13.00 142.43 13.00 136.09 13.00 132.75

83.0 20.9 147.96 8.00 150.83 10.00 148.72 4.00 178.59 4.00 191.84 4.00 176.44 6.70 147.43 7.78 145.58 12.52 142.48 13.00 136.09 13.00 132.75

83.5 20.4 147.89 8.00 150.83 10.00 148.72 4.00 178.59 4.00 191.84 4.00 176.44 6.82 147.24 8.00 145.33 12.68 142.42 13.00 136.09 13.00 132.75

84.0 19.9 147.83 8.00 150.83 10.00 148.72 4.00 178.59 4.00 191.84 4.00 176.44 7.32 146.57 8.00 145.33 12.68 142.42 13.00 136.09 13.00 132.75

84.5 19.4 147.79 8.00 150.83 10.00 148.72 4.00 178.59 4.00 191.84 4.00 176.44 7.82 146.23 8.00 145.33 12.68 142.42 13.00 136.09 13.00 132.75

85.0 18.9 147.77 8.00 150.83 10.00 148.72 4.00 178.59 4.00 191.84 4.00 176.44 8.00 146.24 8.00 145.33 13.00 142.43 13.00 136.09 13.00 132.75

85.5 18.4 147.77 8.00 150.83 10.00 148.72 4.00 178.59 4.00 191.84 4.00 176.44 8.50 146.37 8.00 145.33 13.00 142.43 13.00 136.09 13.00 132.75


• Additional model refinements made during program rollout• Incorporate ISOCH engine through use of fixed load points

• Multiple ISOCH options modeled to match operational policy

• Ability to enforce run order limitations due to maintenance requirements

• Able to model dispatch limitations due to engine vibration issues


• Worked with system operators through summer 2015 to ensure successful model deployment

• Multiple refinements of both dispatch model and results format

• Able to refine model to accurately represent operational practices

• By Q4 2015 had achieved sufficient buy in to begin running the model for outside the operations center


• Model Procedure• Update model input filed based on current plant conditions

• Engine availability, engine ratings, dispatch limitations

• Run model and generate dispatch tables

• Send dispatch tables to system operators, PLEXOS team, Plant Manager, Chief Plant Engineer, and Plant Foreman• Ensures all stakeholders were aware of dispatch instructions

• In the event of system disruption (Outage, return to service, rating change) update inputs, rerun model and distribute updated dispatch tables

Impact of Economic Dispatch

• Primary focus of economic dispatch was fuel savings• Summer 2014 vs 2015 reduced fuel, LO and variable O&M

cost of generation from $159.42/MWh to $156.47/MWh • Total savings of $736,789

• Majority of fuel savings passed on to customers through fuel adjustment

• Reduced summer fuel consumption by 3979 barrels• Direct BELCO savings of $119,355 after fuel adjustment

• Savings gained through greater deployment of more efficient engines and optimal dispatch across plant


• Improved accuracy of modeling• Refinements necessary to facilitate dispatch modeling were

incorporated into other company models

• Modeled plant behavior now more accurately represented actual practices

• Improvement in capital expansion modeling, back casting, and most significantly fuel budgeting


• Generated weekly assessments of plant performance vs model dispatch

• Able to verify accuracy of model and identify incidents of significant deviation• Deviations highlighted disruptions in plant operation

• Facilitated further refinements of the model








• Opportunities for short term forecasting • Dispatch model could be run to provide comparative

dispatches for engine outages, planned maintenance, and changes to engine run order

• Improved data velocity and provided a easy was of quantifying the fuel impact of any plant work

• Data from forecasting was able to support business cases to expedite maintenance works and other plant projects

• Ongoing dispatch program providing continuous record of plant performance• Assurance of optimal plant operation in terms of fuel

efficiency

Development of Automated Dispatch Modeling

• Key limitation of day ahead modeling is the delay between changing plant conditions and updating of dispatch tables

• Additional source of error comes from the deployment of engines• Loads fluctuation between points where engine will be

deployed will call for engine to constantly be taken in and out

• Obviously not possible, defaults to operator discretion


• Issues addressed through development of an automated dispatch model• Provide live dispatch results based on current plant

conditions• No direct control of engine dispatch

• Operates autonomously without constant input from system operators

• Requires minimal PLEXOS training for operation center staff

• Continuous updates based on load and plant conditions


• Input files tied into SCADA system• Constantly updated with load, rating, and engine

availability

• Model run continuously on operations network virtual server

• Outputs saved to CSV files and read to dedicated dashboard

• Continuous record of engine dispatch

Questions

• Thank you

Documents

Use of PLEXOS in Economic Engine Dispatch · •Operated by BELCO system operators, managed by system reliability. Economic Dispatch –Initial Model •Model Limitations •Low ability