IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 25, NO. 2, MAY 2010 657
Weekly Self-Scheduling, Forward Contracting,
and Offering Strategy for a Producer
Lina P. Garcés, Student Member, IEEE, and Antonio J. Conejo, Fellow, IEEE
Abstract—Within a weekly market horizon, this paper considers
a power producer that sells its energy both in the pool and through
weekly forward contracts. The paper provides a methodology that
allows the producer to derive the self-scheduling of its production
units, to select weekly forward contracts, and to obtain the offering
strategy for Monday’s pool. The proposed technique is based on
stochastic programming and allows the producer to maximize its
expected profit while controlling the risk of profit variability. A
comprehensive case study is used to illustrate the characteristics
of the proposed methodology. Appropriate conclusions are finally
drawn.
Index Terms—Offering strategy, risk management, stochastic
programming, weekly forward contracting, weekly self-sched-
uling.
NOTATION
The main notation used throughout this paper is stated below
for quick reference. Other symbols are defined as needed
throughout the paper.
A. Variables:
Generation cost in Monday period and
scenario ( ).
Generation cost in period of weekdays
other than Monday, Monday scenario , and
week scenario ( ).
Shut-down cost incurred by unit in Monday
period ( ).
Shut-down cost incurred by unit in period
of weekdays other than Monday ( ).
Power generated by the th block of unit in
Monday period and scenario (MW).
Manuscript received May 13, 2009; revised August 19, 2009. First published
November 10, 2009; current version published April 21, 2010. The work of
A. J. Conejo was supported in part by the Government of Castilla-La Mancha,
Project PCI08-0102, and in part by the Ministry of Education and Science of
Spain, CICYT Project DPI2006-08001. Paper no. TPWRS-00348-2009.
L. P. Garcés is with the Paulista State University, Ilha Solteira, Brazil (e-mail:
linaneg@aluno.feis.unesp.br).
A. J. Conejo is with the University of Castilla-La Mancha, Ciudad Real, Spain
(e-mail: Antonio.Conejo@uclm.es).
Digital Object Identifier 10.1109/TPWRS.2009.2032658
Power generated through the th block of
unit during period of weekdays other
than Monday, Monday scenario , and week
scenario (MW).
Power sold through the th block of forward
contract (MW).
Power sold in the pool during Monday period
and scenario (MW).
Power sold in the pool during period
of weekdays other than Monday, Monday
scenario , and week scenario (MW).
Binary variable which is equal to 1 if unit
is online during Monday period , and 0
otherwise.
Start-up cost incurred by unit in Monday
period ( ).
Start-up cost incurred by unit in period of
weekdays other than Monday ( ).
Binary variable which is equal to 1 if unit
is online during period of weekdays other
than Monday, and 0 otherwise.
Value at risk.
Auxiliary variable used to compute the
conditional value at risk (CVaR).
B. Constants:
No-load generating cost of unit ( /h).
Incremental generating cost of the th block of
unit ( /MWh).
Start-up cost of unit ( ).
Shut-down cost of unit ( ).
Time periods spanned by contract (h).
Time duration of Monday period (h).
Time duration of period of weekdays other
than Monday (h).
Maximum power that can be sold through
block of forward contract (MW).
Capacity of unit (MW).
0885-8950/$26.00 © 2009 IEEE