WORKSHOP ONUTILITY WIND INTEGRATION STUDIES:
MODELS ANDMETHODS
Panel 6 – Base Load Unit Cycling Costs
Gene Danneman P.E.
June 24 & 25, 2010
2
Thermal Plant Wear and Tear(Wind Wear)
Wind Penetration
Wind and solar load ramps faster than
load demand
Thermal Plants mission changesSystem bottoming
Ramp rate – up/downRamp range# of cycles
Increased thermal cycles
cause additional wear and tear
Metal Fracture causes
forced outage
Forced outages Increase - $$
Cost OptimizationDispatch
OperationsMaintenance
Capital retrofitsResource planningNew Flexible Units
Mitigate costs / risks
Start Here -
Wear and Tear
3
MN Wind 2008/2009 (smoothed)
Day of year
MW / hour (smoothed)
Time of Day
4
Load, Wind and Net Load: January 2013 – System Bottoming
5
Conventional Plant Challenges of Wind Integration
More Net Load Ramp Up & Down cycles on all units
More Turn-down on baseload units Lower unit minimums Faster ramps up and down
Greater Cumulative System Variability (Net Load = Load - Wind)
Increased Starts/Stops on Gas-fired units Gas pipeline balancing & coal supply
issues
More Net Load Ramp Up & Down cycles on all units
More Turn-down on baseload units Lower unit minimums Faster ramps up and down
Greater Cumulative System Variability (Net Load = Load - Wind)
Increased Starts/Stops on Gas-fired units Gas pipeline balancing & coal supply
issues
6
Load CyclingLL1 Lowest Load at Which Design Superheater / Reheater Temperatures can be MaintainedLL2 Current “Advertised” Low Load (~AGC minimum)LL3 Lowest Load at Which the Unit can Remain On-Line
Generation Unit CyclingDefinitions
7
Deep Load Following Scenario
Safe, Stable, Environmentally Compliant
Down- Up Ramp Rate
Time
Ancillary Services
$?
~95% FULL Load
LL1
LL2
MW
8
Cycling Effects
Lost Generation
5 10 15 20 25 30 35 40 45 50
Unit Upgraded (Capital Added)
Eq
uiv
alen
t F
orc
ed
Ou
tag
e R
ate
(%)
600 MW Baseloaded600 MW Cycling and Upgraded for Cycling600 MW Cycling - No Upgrades for Cycling600 MW Cycling and Designed for Cycling600 MW Cycling Arrows Show Infusion of Capital Spending
Cycling Begins
Age in YearsShaded Area = Cycling-Related
Reduced Plant Life
5
10
15
20
0
25
30
x
9
Increased O&M costsReduction in the life of key plant components and overall unit life
Decrease in overall unit reliabilityIncrease fuel cost
Consequences of Cycling Damage - $$$
10
Unit Flexibility Options – Many Moving Parts
Unit Operation
Fatigue Stress cycle damage
Unit Maintenance
Cycle Damage EFOR PdM/PMs
System Dispatch
Lower Cycling costs
Energy and CapacityTransactions
Impact on cycle wear Resource Planning
Low cost flexible resources
Unit Upgrades
Improve flexibility
Optimize Overall System Costs
Fuel Flexibility
emissions
Recommended
