Electric Department
502 Carroll, Ames, IA 50010
Customer Service
515 Clark
Ave., Ames, IA 50010
Phone:
(515) 239-5120
* * * * *
How to Calculate Your Electric Costs
General Power (Commercial) Rate Large Power (Industrial) Rate
The residential electric rate is available for all single-phase domestic uses in separately metered dwelling units that are intended for occupancy by a single ordinance. This rate would apply to most owner or renter occupied housing where the electricity is metered separately for each unit.
The residential electric rate is made up of three components: The Service Charge, the Energy Charge and the Energy Cost Adjustment (ECA).
Service Charge - The service charge is a fixed fee
each month and is also the minimum bill amount. The monthly service charge for residential
customers is $3.65.
Energy Charge - The energy charge is the amount you pay for each kilowatt hour that
you use. The rate is broken up into three blocks with the rate per kilowatt hour declining
with each higher block of consumption. The rate per kilowatt hour (kWh) is also different
for summer and winter:
| Summer | Winter | |
| First 400 kWh | 7.97¢ per kWh | 7.04¢ per kWh |
| Next 600 kWh | 7.56¢ per kWh | 5.90¢ per kWh |
| Remaining kWh | 6.93¢ per kWh | 5.59¢ per kWh |
The summer rate is in effect for utility bills that are
mailed on or between July 1 and October 31. This means that the summer rate would normally
apply to electricity consumed from June through September. The remaining eight months are
billed at the winter rate.
Energy Cost Adjustment (ECA) - The ECA is a component that allows the
utility to reflect fluctuations in the cost of fuel for the power plant without frequently
changing the standard energy charges shown above. When rates were set in 1987,
a base fuel cost was projected. The ECA is simply the difference between actual fuel costs
for the past twelve months and the projected base fuel cost. Contracts for
coal have increased and this is reflected in the current ECA. For the month of
January, 2008 the ECA was $.0169per kWh.
If a residence consumed 1050 kWh during the month of May, the electric cost would be calculated using the winter rate as shown above:
| Service Charge | $ 3.65 |
| First 400 kWh X $.0704 | $28.16 |
| Next 600 kWh X $.059 | $35.40 |
| Remaining 50 kWh X $.0559 | $ 2.80 |
| ECA=1050 kWh X $.0169 | $17.75 |
| Total Cost: | $87.76 |