When you receive your monthly electric bill, do you look at anything other than the total? If so, you’re not alone.

Among the many line items that may appear, understanding the “when and how” of your electricity consumption is helpful in evaluating what may drive usage related costs.

The screen shot below, extracted from the Constellation NewEnergy Online tool, provides an example of a customer’s interval energy consumption, reflecting customer demand (how much electricity a customer is using across all of its interval meters at one point in time) within a certain period.

Source: Constellation NewEnergy Online

The screen shows a customer whose usage increased dramatically at 10 a.m. Although this increase resulted in the use of only a few extra kilowatt-hours (kWh) of usage during that month, it can end up costing a lot more.

For example, the extra usage shown on the left resulted in the kWh going up only 1% for the month, but demand went up 20%. If this run-up in demand happened during a peak capacity period for the independent system operator (ISO), the extra kW’s pulled during this time could cost the customer throughout the next year. Also if this run-up in demand was the highest demand for the entire month, then the customer’s peak distribution demand charge could increase for that month.

If you see these types of short-term jumps in your usage, you can examine your facility to determine the source.  Examples of why usage can spike include:

• The number of motors starting roughly at the same time.
• Air conditioners and chillers all starting simultaneously in the morning.
• Lighting banks set to come on at the same time.
• Inefficient motors that pull extra power to begin to turn.
• Lots of electric heat starting at the same time.
• Ovens timed to start at the same time.

By starting up electric equipment at different times, you can dramatically lower your peak demand. To potentially lower costs, you may also want to consider starting some of your motors earlier and get them running at full speed before starting the next motor. You can also turn on some of your air conditioners earlier to pre-cool the building to reduce the peak demand rather than starting them at the same time.

Joseph A. Franz, Vice President of Product Management at Constellation NewEnergy, works on developing products and solutions to help customers more effectively manage their energy costs. This is his first post on the NewEnergy Blog.