The difference between Firm and Dual Fuel customers
The vast majority of CenterPoint Energy's customers in Minnesota are Firm customers who require an uninterrupted flow of gas. A few thousand commercial and industrial customers are Dual Fuel customers who have the capability of discontinuing natural gas use during occasional curtailment periods. Most have systems that will burn an alternate fuel.
Curtailment is necessary when CenterPoint Energy is unable to provide natural gas to all of its customers because:
Customer demand exceeds the amount of interstate pipeline capacity for which the company has contracted. This typically happens during the coldest days of the year.
Pressure problems or physical disruptions on the gas distribution system occur.
Supplies are limited.
The curtailment process
During curtailment periods, Dual Fuel customers are asked to curtail their use of natural gas by switching to an alternate fuel within one hour. Customers with multiple interruptible accounts may be eligible for more time to curtail through the One-Call Option.
In return for the occasional disruptions, Dual Fuel customers receive a discount on the delivery portion of their natural gas bill all year. This process ensures that all customers who depend on uninterrupted natural gas service get the gas they need at all times.