What is Demand?

Why is there a “demand” charge on my bill?
We are all used to seeing a charge on our monthly bills for kilowatt hours (kWh) – a measure of total units of energy we consume. Demand charges have historically been spread across our whole membership as part of the cost of service. That’s changing.

But what is demand?
Demand (expressed as kilowatts, or kW) is a measure of maximum average power usage over a 15 minute period during the billing cycle. While a kilowatt hour is a measure of the total energy we use over a specific billing cycle, demand is a measure of the fastest rate at which we consumed energy over a specific billing cycle. For example, when temperatures suddenly drop and a lot of members turn their heaters on at the same time, typically during high peak demand periods such as 8 AM and 6 PM, demand on the OPALCO system spikes.

Why is demand important? Demand is important because the OPALCO electrical system has to be built to handle the peak usage.

OPALCO pays demand charges to Bonneville Power Administration (BPA) when the loads go up higher than our agreed-upon forecast, most often during a cold spell.

How does demand affect members?
Starting in 2015, the rate structure will gradually allocate these demand charges to each member for their actual demand or load placed on the system over the next seven years, bringing greater parity to the membership.

For more information, please contact us.