Charge Scheduling of an Energy Storage System under Time-of-Use Pricing and a Demand Charge
Table 4
Comparison of simulation results for a single day.
Instance
NO-ESS
NPB
RCGA
Case
Rate
Season
Weather
Day type
Cost
Cost
Saving
Ave. cost (Std.)
Saving
1
Low
Summer
Sunny
Weekday
83.69
68.76
18
63.87 (0.63)
24
2
Low
Summer
Sunny
Weekend
82.28
65.42
20
62.90 (0.61)
24
3
Low
Summer
Cloudy
Weekday
104.64
91.42
13
86.19 (1.09)
18
4
Low
Summer
Cloudy
Weekend
111.40
107.71
3
98.32 (1.09)
12
5
Low
Winter
Sunny
Weekday
185.43
161.05
13
150.08 (0.97)
19
6
Low
Winter
Sunny
Weekend
176.93
152.00
14
140.67 (1.22)
20
7
Low
Winter
Cloudy
Weekday
225.68
221.86
2
197.37 (0.74)
13
8
Low
Winter
Cloudy
Weekend
233.26
233.26
0
207.44 (0.69)
11
9
High
Summer
Sunny
Weekday
94.37
79.44
16
71.75 (0.72)
24
10
High
Summer
Sunny
Weekend
92.47
75.44
18
70.43 (0.76)
24
11
High
Summer
Cloudy
Weekday
115.32
102.10
11
96.32 (1.20)
16
12
High
Summer
Cloudy
Weekend
121.42
117.73
3
108.42 (1.31)
11
13
High
Winter
Sunny
Weekday
201.45
176.88
12
163.75 (1.26)
19
14
High
Winter
Sunny
Weekend
192.56
166.84
13
153.75 (1.33)
20
15
High
Winter
Cloudy
Weekday
241.70
237.88
2
211.49 (1.09)
12
16
High
Winter
Cloudy
Weekend
248.89
248.89
0
221.26 (0.90)
11
NO-ESS is the cost with no ESS. The NPB algorithm charges the battery when the generated power exceeds the load and discharges otherwise. RCGA is our real-coded genetic algorithm (the average costs are obtained over 100 runs). All costs are in US cents, and savings are percentages. The saving for Algorithm is obtained using the formula, , where is the electricity cost incurred by Algorithm .
