Grid is planning ahead of how to use its mix of available electricity generation plants to meet electricity demand for t

[answerhappygod]

Grid is planning ahead of how to use its mix of available
electricity generation plants to meet electricity demand for the
year 2022. It currently has at its disposal seven different types
of plants ranging from Hydro Electric (HYDRO), Combined Cycle Gas
Turbine (CCGT1 and CCGT2), Open Cycle Gas Turbine (OCGT), Coal
(CL), Wind (W), and Solar (S) that it can use to meet the 2022
demand. Table 1 provides relevant technical and operational cost
data on the different plants.
Generator Type
Available Capacity (MW)
Availability Factor
Operational Cost ($/MWh)
Emissions Cost ($/MWh)
HYDRO
1360
60%
2
0
CCGT1
1100
50%
70
7
CCGT2
900
55%
67
8
OCGT
1000
60%
178
10
COAL
400
68%
30
18
WIND
100
17%
10
0
SOLAR
200
20%
2
0
Note that electricity demand is in either Megawatts hour (MWh)
or Gigawatts hour (GWh), whereas plant capacity is in Megawatt
(MW). Thus, for instance, a plant of say 200MW is capable of
producing, in a 10 hour window, an amount of 200MW*10h =
2000MWh. However, it is possible that the plant might not be
fully available for the 10 hours due to several factors including
making time for maintenance, fuel shortage, etc. Because of this,
the 2000MWh which is the maximum it can generate in 10 hours must
be multiplied by the availability factor (as indicated in column 3
of Table 1). For example, if the availability factor is 60%, then
the total electricity the plant can generate within the 10 hours
interval is 200MW*10h*0.6 = 1200MWh.
Table 1 also gives cost of operation, which factors into account
fuel cost, fixed operating and maintenance cost, and other variable
cost, for every MWh of electricity generated by a plant. In
addition, GridCo has been tasked by the government to surcharge
plant for the emissions that accompanies every MWh of electricity
generated.
Whatever Grid does, it must adhere to contractual
obligations. Current contract agreement requires that
Grid buys, respectively, not less than 50%, 90%, and 90% of
the electricity that an OCGT, WIND, and SOLAR plants are capable of
generating (i.e. after accounting for availability factor).
GridCo can also purchase electricity from neighbouring countries
at a cost of $250/MWh if it so desires.
Demand in 2022 is not certain but is expected to be any of the
data points shown in Table 2 below.
Table 2: Possible electricity demand (in GWh) in 2022
21696
24085
19454
21578
23862
22344
19169
21320
22201
21379
21280
21985
21022
22066
22337
21635
23212
21219
22699
23670
Though demand is uncertain, use the average of the possible
demands to represent the demand expected in 2022.
Assume there are 365 days in year and answer the following
questions.
i. What do you think is the implicit
objective of GridCo in meeting the electricity demand expected in
2022? Explain.
ii. Formulate a linear programming model to help GridCo achieve
its objective