Date post: | 15-Dec-2015 |
Category: |
Documents |
Upload: | jean-riding |
View: | 219 times |
Download: | 0 times |
Methodology Summary
•Estimate value of CVP power by comparing the
differential costs for two scenarios:
• With fully-functional CVP
• Without CVP, but with replacement portfolio
• Study is performed with CVP constraints modeled
•PLEXOS is used to determine the difference in variable
costs between the two scenarios
• Capital and fixed operating costs are from another source
PLEXOS Overview• Fundamental market simulation model (supply
and demand)• Minimizes total market cost for all variables:
• Energy and ancillary services (AS)• Fuel and variable operating expenses• Emission costs (if modeled)• Wheeling costs and losses
• Subject to 1000s of constraints:• System load and AS• Plant performance• Transmission capability• Uncertainty of variable-energy resources
Solving UC/ED using MIP
• Unit Commitment and Economical Dispatch can be formulated as a linear problem (after linearization) with integer variables of generator on-line status
Minimize Cost = generator fuel and VOM cost + generator start cost+ contract purchase cost – contract sale saving + transmission wheeling + energy / AS / fuel / capacity market purchase cost – energy / AS / fuel / capacity market sale revenue
Subject to– Energy balance constraints– Operation reserve constraints– Generator and contract chronological constraints: ramp, min up/down, min capacity,
etc.– Generator and contract energy limits: hourly / daily / weekly / …– Transmission limits– Fuel limits: pipeline, daily / weekly/ … – Emission limits: daily / weekly / … – Others
Integration of Mid- and Short-Term Constraints
• PLEXOS includes three integrated algorithms:
– Long-, mid-, and short-term
– Three perspectives are seamlessly integrated
– Mid-term simulation decomposes hydro, fuel, emission, and energy constraints for the short-term simulation
– CALSIM monthly output decomposed into daily amounts for short-term
Long-term security assessment
Maintenance planning and outage assessment
Mid-term simulationResolve and price emission /fuel/
energy constraints
Short–term simulationFull chronological simulation
Detailed Generator Modeling
• General chronological constraints modeled, i.e.,– Minimum up and down time– Ramp up and down rate– Minimum capacity with hourly economic or must-run status– Reserve (regulation up/down, spinning and non-spinning) provision
capacities– Start cost as a function of number of hours being down– Forbidden operation zone
• User-specified fuel mixture / mixture ranges or model-determined fuel mixture
• Heat Rate as a function of fuel types– Average heat rate for multiple loading points– Incremental heat rate for multiple loading points– Polynomial fuel-generation IO curve
• Emission rate with removal rate• Initial commitment and dispatch status
Combined Cycle Modeling, continued
HR=10316 Btu/kWhEfficiency=33%
Boiler efficiency = 80%
~
Gen=160 MWh
Gen=160 MWh
Fuel=1.68e+9 Btu
Fuel=1.68e+9 Btu
Duct Burner Fuel=1.45e+8 Btu
HR=10500 Btu/kWhEfficiency=32.5%
HR=10500 Btu/kWhEfficiency=32.5%
Energy content of electricity = 3412 Btu/kWh
Waste=1.134e+9 Btu
Waste=1.134e+9 Btu
1.96004e+9 Btu
~~
PLEXOS Hydro Modeling
• Inflows, storages, plants, and spills are modeled and optimized on an hourly basis– In terms of either acre-feet (volume) or MWh
• The hydro contribution is maximized given energy and AS markets (or system requirements)
• Hydro is fully integrated with the thermal (hydro-thermal integration) and is perfectly arbitraged against all available markets
An Example of Cascaded Hydro System
Inflow
Storage II
~P/S 2
Storage III
Storage V
Storage I
Sea
Inflow
Inflow
Inflow
~P/S 1 ~P/S 3
~H 2~H 1 ~H 3
~H 6
~H 4 ~H 5
Storage VI
LT-Plan: PLEXOS for Integrated Resource Planning
• Alternative portfolio development methodology
• Objective: Minimize net present value of forward-looking costs (i.e. capital, fixed operating and production costs)
Production Cost P(x)
Capital Cost C(x)
Total Cost C(x) + P(x)
Cost ($)
Investment xOptimal Investment x*
Primary Data Sources
• WECC TEPPC (Transmission Expansion Planning Policy Committee) regional database (version PCO)
• CA Utility LTPP (Long-Term Power Plan) revisions and updates for CA
• CVP-specific information
Selected Examples of Data Input to PLEXOS• Simulation year – 2020
• Base year for dollars – 2010
• CA hydro aggregated in two zones– Northern and Southern California– CVP extracted from aggregated hydro
Data Inputs II
• CAISO 2011-2020 Changes (MW)– Summer Peak Load
• Summer peak load = 6,200 MW
• Demand-side reductions = 8,100 MW
• Net peak summer load = (1,900 MW)
– Summer Generation Capacity
• Retirements = 13,100 MW
• New additions = 11,100 MW (Thermal, RPS)
• Net summer capacity = 2,000 MW– primarily RPS and OTC replacement
Data Inputs III
• CAISO 2011-2020 Changes (MW)– Renewable Portfolios
• In-state = 14,200 MW
• Out-of-state = 5,093
• In-state renewable types– Hydro = 0 MW– PV Solar = 4,600 MW– Solar Thermal = 3,600 MW
– Wind = 5,034 MW
• Out-of-state renewable
• Wind = 5,000 MW
Data Inputs IV
• Natural gas prices (2010 $)– PG&E Citygate -- $5.61 / MMBtu (delivery to burner-tip adds 7 to 23
cents / MMBtu)
– SoCal Border -- $5.41 / MMBtu (delivery adds 44 cents / MMBTU)
– Current Price (1/4/2013) -- $3.30 to $3.60 / MMBtu (source: California Energy Markets)
• CO2 Emission Price (2010 $)– $36.30 (short-ton CO2)
• CA Net Exchange (summer peak)– 16,400 MW
Selected Acronyms
• AS – Ancillary Services
• CAES – Compressed air energy storage
• CAISO – CA Independent System Operator
• CO2 – Carbon dioxide
• LTPP – Long-Term Procurement Plan
• OTC – Once-Through Cooling
• TEPPC – Transmission Expansion Planning Policy Committee (WECC regional database for market simulation purposes)
• WECC – Western Electric Coordinating Council