Did you know our schools are billed twice for our electricity use? Well, technically there are two components to our school’s electricity bill - the energy charge and the demand charge. The bills we see at our homes have the cost per kilowatt hour of electricity used, but schools and other commercial buildings are also charged for their peak demand load.
Here is how electric energy is billed for a school:
1. Energy Charge (use over time): Electricity is typically metered at each school facility to determine the amount of kilowatt hours used. This meter is read each month and the difference in the readings accounts for the total consumption; school are billed accordingly.
2. Demand Charge (use at one point in time): Utility companies look at the highest peak of electric use during the month. For example, during the month of December, the total peak demand will be measured every fifteen minutes and charted on a graph. The highest electric load during the month is what the utility will bill for demand. So in other words, if one day out of the month you have everything powered to full blast, that’s the day you’ll be charged for all month.
Why does a utility company have this charge?
Electricity-consuming equipment in a school determines the school’s demand for electricity. As electric use fluctuates during the day and during various seasons, it creates unknown electric load demands for a utility company. In order to accommodate for this, the utility company needs to know the maximum amount of electricity required to provide to their customers.
How can schools help reduce this electricity charge?
Focus on reducing energy use from 11am – 2pm, since that is when occupancy and energy use are highest. In fact, lunch hour is typically the most energy-intense time of the day in a school. Building engineers are trained on how to schedule their large equipment to lower their peak demand load. It is important to understand this concept in case you do play a role in a strategy to reduce these demands costs.