Peak Demand

A program for our Iowa residential and small business electric customers

Your monthly Peak Demand could save you money

What is Peak Demand?

Your peak demand is the point during your monthly billing cycle where you use the most energy. It's the highest spike in your energy use. Your peak changes from month to month depending on how you use your energy. Check out this short video that explains your peak demand.

How am I billed on Peak Demand?

The program looks at your highest peak demand during "on-peak hours" and your highest peak demand during "off-peak hours." Calculations from these two "peaks" are how your bill is determined.

On-peak hours are between 7 a.m. - 8 p.m. Monday - Friday. All other hours are considered off-peak.

You will need your energy demand printed on your bill. With this information, you can use our Peak Demand calculator to see if your energy usage makes you a good candidate for the program.

How do I get my energy demand printed on my bill?

Fill out this form to get started.

This is how your bill will change [PDF]. Save these numbers. You will need them to use the Peak Demand calculator later.

How do I use the energy demand information printed on my bills?

Use the Peak Demand calculator (for residential customers or general service/business customers) to see if you would have saved money on the Peak Demand program. Here's a guide to help you fill out the calculator [PDF]. Do this once per month to see over time if the program would work for you.

If the calculator shows that you would have saved money on the Peak Demand program, congratulations! If your habits remain the same, you are a good candidate for the program. Just call us at 1-800-ALLIANT (800-255-4268) to switch to Peak Demand. You will be enrolled by the next billing cycle after we process your request.

If the calculator shows that you would not have saved money, you may be better off staying on the regular rate. But - if you want to change your habits and keep trying the calculator over time, that's okay too! You can switch to the Peak Demand rate any time. When you switch to Peak Demand you are enrolled for 12 months.

What are some easy ways to adjust my energy usage habits?

  • Only wash and dry your laundry after 8 p.m. and on weekends.
  • Only run your dishwasher after 8 p.m. at night and on weekends.
  • If you have electric heat and air conditioning, adjust the temperature during weekday hours. A smart thermostat makes it easy.
  • You may also want to sign up for a system like Sense, which monitors your home's energy usage.

Program terms and conditions

The Peak Demand rate is available to Iowa electric residential and small general service customers under the following rate codes:


400 Regular Electric Residential Service Usage
407 Time of Day
450 Electric Residential Second Nature 100%
457 Electric Residential TOD Second Nature 100%
460 Electric Residential Second Nature 50%
467 Electric Residential TOD Second Nature 50%
470 Electric Residential Second Nature 25%
477 Electric Residential TOD Second Nature 25%


600 Electric Non-Residential General Service
607 Electric Non-Residential General Service-TOD

Peak Demand is a program offered by Interstate Power and Light Company (IPL) under the Optional Demand tariff filed with the Iowa Utilities Board, available online.

Customer contact information

Enrollment and cancellation

Customers electing to participate in Peak Demand must follow the following steps:

  1. Contact ײƵ at 1-800-ALLIANT (1-800-255-4268) or email and request to have their on-peak and off-peak demand printed on their monthly bills. Customer may also request their peak demand printed on their bills by filling out the request form.
  2. Customers must use the printed demand information and the supplied rate calculator (for residential customers or general service/business customers) to determine if they might save money on their monthly bill. Because Peak demand fluctuates from month to month, it may take several months to determine if a customer could save money on the Peak Demand rate.
  3. There is no cost to have on-peak and off-peak demand printed on bills.
  4. After testing monthly demand against several months of billing, the customer may then sign up for the Peak Demand rate by calling 1-800-ALLIANT (1-800-255-4268) or by emailing
  5. Customers will be enrolled in the program effective with the customer's next feasible meter reading date after the company is notified by the customer.
  6. Customers may cancel from the program after 12 months of participation. There is no cost to cancel participation.

Rate structure

The Peak Demand rate is calculated by using on-peak and off-peak demand.

  1. If the on-peak demand is larger than the off-peak demand, the charge is calculated by using only the on-peak kilowatts.
  2. Of the off-peak demand is larger than the on-peak demand, the charge is calculated by taking 50% of the difference between the two peaks and adding that usage to the on-peak demand.
  3. The Peak Demand rate is a base rate and does not include energy and transmission costs, franchise fees, energy efficiency, demand response, and renewable energy charges or taxes.

Recent stories from our blog