Electricity bills can include two distinct types of charges: energy charges and demand charges. While residential customers typically see only energy charges, commercial and industrial customers often face both. Understanding the difference helps you manage costs and optimize usage.
What Are Energy Charges?
Energy charges are based on the total amount of electricity you consume over a billing period, measured in kilowatt-hours (kWh). If you use 1,000 kWh at $0.12 per kWh, your energy charge is $120. This is the "volume" component—how much you used in total.
What Are Demand Charges?
Demand charges are based on your peak power demand—the highest rate at which you drew electricity during the billing period, measured in kilowatts (kW). Utilities must size their infrastructure to meet peak demand, so they charge for that capacity even if you only hit the peak briefly.
Why Demand Matters
Imagine running your AC, oven, and laundry simultaneously for 15 minutes. That spike in usage could set your demand for the month. Even if you use little electricity the rest of the time, that peak determines your demand charge.
- Energy charge: Pays for total kWh consumed.
- Demand charge: Pays for the highest kW drawn at any moment.
"Spreading high-power activities throughout the day can lower your demand charge, even if your total energy use stays the same."
Who Pays Demand Charges?
Most residential customers do not have separate demand charges; their bills are based primarily on kWh. Commercial, industrial, and some large residential customers often have demand charges because their peak usage significantly impacts the grid.
How to Reduce Demand Charges
If you're on a demand rate, avoid running multiple high-power appliances at once. Stagger HVAC cycles, schedule heavy equipment for off-peak times, and consider demand response programs that reward you for reducing peak usage.