Comparision of E-8 vs E-7 billing rate schedules for our household
For June 19, 2003 through June 17, 2004 we used an average of 45KWH/day and would have saved roughly $500 if we had been on an E-7 schedule instead of the E-8 billing rate schedule that we were actually on.
Surcharges apply equally to the KWH whether on the E-8 or the E-7 schedule so they were excluded from the analysis.
The 10% legislated reduction and the 5% tax would throw off the numbers by about 5%, but were not included.
If we went from 45KWH/day back to 80KWH/day with the additional power spread evenly 24x7 how much of the $500 do we lose?
added KWH/day Season seasonal days/yr   peak vs off-peak hrs /wk peak vs off-peak % usage KWH/yr Baseline KWH rate E-8 Baseline KWH rate E-7 $/yr E-8 $/yr E-7 $ E-7 costs more than E-8
35 Summer 184 Peak 30 18% 1150 $0.12017 $0.31524 $138 $363  
      off-peak 138 82% 5290 $0.12017 $0.08515 $636 $450  
35 Winter 181 Peak 30 18% 1131.25 $0.07308 $0.11636 $83 $132  
      off-peak 138 82% 5203.75 $0.07308 $0.08851 $380 $461  
  Annual 365       12775     $1,237 $1,405 $168
How many additional KWH/day (spread evenly 24x7) to offset $500 of E-7 savings?
added KWH/day Season seasonal days/yr   peak vs off-peak hrs /wk peak vs off-peak % usage KWH/yr Baseline KWH rate E-8 Baseline KWH rate E-7 $/yr E-8 $/yr E-7 $ E-7 costs more than E-8
104 Summer 184 Peak 30 18% 3417.14 $0.12017 $0.31524 $411 $1,077  
      off-peak 138 82% 15718.86 $0.12017 $0.08515 $1,889 $1,338  
104 Winter 181 Peak 30 18% 3361.43 $0.07308 $0.11636 $246 $391  
      off-peak 138 82% 15462.57 $0.07308 $0.08851 $1,130 $1,369  
  Annual 365       37960     $3,675 $4,175 $500
How many additional KWH/day (all during peak hours) to offset $500 of E-7 savings?
added KWH/day Season seasonal days/yr     peak vs off-peak % usage KWH/yr Baseline KWH rate E-8 Baseline KWH rate E-7 $/yr E-8 $/yr E-7 $ E-7 costs more than E-8
11.44 Summer 184 Peak   100% 2104.96 $0.12017 $0.31524 $252.95 $663.57  
      off-peak   0% 0 $0.12017 $0.08515 $0.00 $0.00  
11.44 Winter 181 Peak   100% 2070.64 $0.07308 $0.11636 $151.32 $240.94  
      off-peak   0% 0 $0.07308 $0.08851 $0.00 $0.00  
  Annual 365       4176     $404 $905 $500
What ratio of peak usage to off-peak usage will result in no difference between E-8 and E-7?
added KWH/day Season seasonal days/yr     peak vs off-peak % usage KWH/yr Baseline KWH rate E-8 Baseline KWH rate E-7 $/yr E-8 $/yr E-7 $ E-7 costs more than E-8
10 Summer 184 Peak   7.8% 143.52 $0.12017 $0.31524 $17.25 $45.24  
      off-peak   92.2% 1696.48 $0.12017 $0.08515 $203.87 $144.46  
10 Winter 181 Peak   7.8% 141.18 $0.07308 $0.11636 $10.32 $16.43  
      off-peak   92.2% 1668.82 $0.07308 $0.08851 $121.96 $147.71  
  Annual 365       3650     $353 $354 $0