HomeWattCost

Alliant Energy (Interstate Power and Light) rates

Alliant Energy has 2 residential plans modelled here. For a typical Iowa home using 856 kWh a month, the cheapest is 400, at about $166 a month.

Investor-owned 417,153 residential customers (EIA-861, 2024) Tariffs checked September 28, 2026

Typical all-in price400

01234567890123456789.0123456789¢/kWh
400$166/mo
407$166/mo

Residential plans

PlanTypeFixed/moJuly pricesJanuary pricesJuly weekday windows
400
Residential Service
Flat $15.51 20.0¢ all hours 16.6¢ all hours None
407
Residential Time of Day
Time-of-use $15.51 Off-peak 17.8¢ · Peak 28.9¢ Off-peak 16.6¢ Peak 2 pm–7 pm

407: price by hour

July weekday. Summer pricing Jun–Aug; winter Sep–May.

Off-peakPeak
17.8¢28.9¢17.8¢12a3a6a9a12p3p6p9p12a

Charging an EV on Alliant Energy

1,000 miles a month in a Tesla Model Y Long Range AWD (275 kWh from the wall, EPA 27.5 kWh/100 mi) at 7.2 kW, added to a typical Iowa home’s use, on each plan’s cheapest start hour versus plugging in at 6 pm. Averaged over the year.

PlanBest startCharging, best startCharging from 6 pmWhole bill with EV
400Any$48/mo$48/mo$214/mo
40712 am$46/mo$51/mo$213/mo

With an EV charged at its best hour, the cheapest plan overall is 407. Compare plans on your own usage.

How Alliant Energy’s plans work

400 (Residential Service). One price per kWh at every hour: 20.0¢ in July and 16.6¢ in January. Shifting use to other hours changes nothing on this plan; using less is the only lever. Fixed charge: $15.51 a month.

407 (Residential Time of Day). Peak 2 pm–7 pm on July weekdays; 5 of 24 hours carry the top price of 28.9¢. The cheapest July weekday hour costs 17.8¢, so moving 1 kWh out of the top hours saves 11.1¢. In January every hour costs the same (16.6¢). Summer pricing applies Jun–Aug; winter pricing Sep–May. Weekends follow a different schedule from weekdays. Fixed charge: $15.51 a month.

Prices on this page are all-in per kWh, before taxes: base rates, supply and every per-kWh rider in the utility’s current tariff sheets. Your bill shows them as separate lines, and riders can change between tariff revisions.

As a cross-check, Alliant Energy billed its residential customers an average of 17.90¢ per kWh in 2024 (revenue ÷ sales, EIA-861). A plan taken from URDB is shown only if its all-in price is consistent with that figure, adjusted for Iowa’s price change since.

Sources for each plan

Plans marked “Checked” were transcribed from the utility’s current tariff and rider sheets, all charges included, and are re-checked on the date shown in each file. Other plans come from the OpenEI U.S. Utility Rate Database (CC BY 4.0) and have not yet been checked line by line against the utility’s tariff. Always confirm the current rates on your utility’s website before switching plans.

Run the numbers on Alliant Energy