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Tariff data · 2026-08-27
← Interstate Power and Light Co · IA

Electric Residential Service Optional Demand - 507

When does peak hit on Interstate Power and Light Co’s Electric Residential Service Optional Demand - 507? Peak hits 2pm–7pm every day, all year.

  • peak12.53¢
  • mid7.73¢
  • off-peak7.24¢
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Every hour of the year at this rate, drawn to scale — 24 hours across, 12 months deep, height is ¢/kWh. The tallest bar is 12.5¢ (Jun, 2pm), the shortest is 7.2¢ (Jan, midnight) — 1.7× apart.
Weekdays
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Weekends
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

What does Electric Residential Service Optional Demand - 507 cost a year?

HouseholdUsesA monthPer yearWorks out to
Apartment

One or two people, no central air, no electric heat

4,866 kWh$46$55611.4¢ / kWh
Family home

Three or four people with central air conditioning

9,453 kWh$77$9219.7¢ / kWh
Home with an EV

Same house, plus an electric car charging overnight

13,103 kWh$99$1,1909.1¢ / kWh

Estimates, not quotes. We run three made-up but realistic households through this tariff hour by hour for a full year — including the way air conditioning loads the afternoon and an EV loads the small hours. Your own bill depends on when you actually use electricity, which is exactly the thing a per-kWh number hides.

What you actually pay

PeriodRateApplies when
peak12.53¢2pm–7pm, June–August
mid7.73¢7pm–2pm, midnight–midnight, June–August
off-peak7.24¢midnight–midnight, September–May

Plus a fixed charge of $0.5096 per day — so longer months cost more before you use a single kWh.

This plan also bills a demand charge based on your highest single hour of usage. We don’t price that yet, so treat any total here as incomplete.

Should you be on Electric Residential Service Optional Demand - 507?

This plan bills a demand charge on top of the per-kWh rates: a fee tied to your single highest hour of the month. Two homes using the same total electricity can pay very different amounts if one of them runs the dryer, the oven, and the car charger at the same moment. We do not price demand charges yet, so treat every dollar figure on this page as a floor, not a total.

Before a single kilowatt-hour moves, this plan charges $186 a year in fixed fees. On the apartment above that is 33% of the whole bill; on the house with a car charging in it, 16%. Fixed charges are invisible in a cents-per-kWh comparison and they punish small users hardest — if you use very little electricity, the headline rate is the least important number on this page.

Expect the bill to move with the calendar. The same family home costs about $114 in July and $58 in February — a $56 spread driven by heating and cooling far more than by anything you chose. Budget against the July figure, not the average, and a summer bill stops being a surprise.

Other Interstate Power and Light plans

Who can be on Interstate Power and Light’s Electric Residential Service Optional Demand - 507?

Eligibility is not our judgement — it is written into the tariff Interstate Power and Light filed. This is what that document says:

Large General Service Usage customers for all electric uses in one establishment adjacent to an electric distribution circuit of adequate capacity. No resale of service is permitted. Customers on this rate must have energy usage of 20,000 kWh or more in each billing month.

Shortened — the clause runs longer in the filing. Quoted from the filed tariff. Your utility decides eligibility, not us; check with them before you switch.

If this is new to you

Where this comes from

Effective
2025-07-01

the date this tariff took effect

Covers
delivery + supply

the ZIP-code service map lists this territory as bundled, so the utility sells delivery and supply together

Enrollment
open to new customers

Tariff document: https://www.alliantenergy.com/-/media/alliant/documents/accountandbilling/ratesandtariffs/iowaelectricrates/electricresoptionaldemand.pdf?la=en&hash=4144084F8D4232CB28012C929A7451CE