AI Summary: Demand Charges
Demand charges are fees based on the highest rate of electricity usage (kilowatts, kW) during any 15-minute interval in a billing period. For Texas commercial accounts, demand charges can represent 30-70% of total electricity costs. Demand is measured separately from energy consumption (kilowatt-hours, kWh) and penalizes peak usage spikes. Reducing demand charges requires load management strategies like staggering equipment startup, installing energy storage, and negotiating favorable demand rates with retail electric providers (REPs).
Demand Charges on Texas Commercial Electricity Bills: Complete Guide
What Are Demand Charges?
Demand charges are fees based on the highest rate of electricity usage (measured in kilowatts, kW) during any 15-minute interval in a billing period. Unlike energy charges (billed per kilowatt-hour, kWh), demand charges penalize peak usage spikes, not total consumption.
For Texas businesses, demand charges can represent 30-70% of total electricity costs, especially for facilities with high peak usage relative to average consumption. Understanding and managing demand is critical for controlling commercial electricity expenses in the ERCOT market.
Key Difference: Energy vs. Demand
Energy Charges (kWh)
- • Measures total consumption over time
- • Unit: Kilowatt-hours (kWh)
- • Example: Running a 10 kW machine for 10 hours = 100 kWh
- • Billed per kWh consumed
Demand Charges (kW)
- • Measures peak usage rate in any 15-minute window
- • Unit: Kilowatts (kW)
- • Example: Running 200 kW of equipment simultaneously
- • Billed per kW of peak demand
How Demand Charges Are Calculated in Texas
Demand charges are calculated by multiplying your peak demand (highest kW usage in any 15-minute interval) by the demand rate ($/kW) specified in your electricity contract:
Monthly Demand Charge = Peak Demand (kW) × Demand Rate ($/kW)
Example Calculation:
- • Peak demand during billing period: 200 kW
- • Demand rate in contract: $10/kW
- • Monthly demand charge: 200 kW × $10/kW = $2,000
This $2,000 demand charge is in addition to energy charges (kWh consumed) and TDU delivery fees.
Critical Point: You pay the demand charge based on your single highest 15-minute usage spike, even if that spike only occurred once during the entire month. This is why demand management is so important—one brief spike can cost thousands of dollars.
Types of Demand Charges in Texas
Texas commercial electricity contracts use different demand charge structures. Understanding which type applies to your business is critical:
1. Simple Demand Charge
How it works: You pay a fixed rate ($/kW) for your peak demand each month. The demand resets at the start of each billing cycle.
Best for: Businesses with consistent monthly usage patterns.
2. Ratchet Demand Charge
How it works: Your demand charge is based on a percentage (typically 50-80%) of your highest historical demand over the past 12 months, even if your current month's peak is lower.
Impact: One unusually high demand spike can increase your bills for an entire year. Common in industrial contracts.
3. Time-of-Use (TOU) Demand Charge
How it works: Different demand rates apply during peak hours (summer afternoons) vs. off-peak hours (nights, weekends). Your highest demand during peak hours determines your charge.
Best for: Businesses that can shift high-demand operations to off-peak hours.
4. Seasonal Demand Charge
How it works: Demand rates vary by season—higher in summer (June-September) when grid stress is greatest, lower in winter and spring.
Strategy: Reduce peak demand during summer months to minimize costs during high-rate periods.
Why Demand Charges Matter for Texas Businesses
Demand charges can dominate your electricity bill, especially for businesses with high peak usage. Here's why demand management is critical:
Real-World Impact Example:
Strategies to Reduce Demand Charges
Texas businesses can significantly reduce demand charges through operational changes and contract optimization:
1. Stagger Equipment Startup
Avoid turning on multiple high-demand machines simultaneously. Stagger HVAC, compressors, and production equipment startup by 15-30 minutes to spread the load.
Savings potential: 10-20% demand reduction
2. Install Demand Controllers
Automated systems monitor real-time demand and temporarily shed non-critical loads (HVAC setback, lighting reduction) when approaching peak thresholds.
Savings potential: 15-30% demand reduction
3. Shift High-Demand Operations
Schedule energy-intensive processes (batch production, equipment maintenance) during off-peak hours or weekends when other loads are lower.
Savings potential: 10-25% demand reduction (especially with TOU demand rates)
4. Install Energy Storage (Batteries)
Battery systems discharge during peak demand periods, reducing grid draw. Batteries recharge during low-demand periods when electricity is cheaper.
Savings potential: 20-40% demand reduction (high upfront cost, best for large facilities)
5. Upgrade to Energy-Efficient Equipment
Replace old HVAC systems, motors, and lighting with high-efficiency models that draw less power during operation, reducing peak demand.
Savings potential: 5-15% demand reduction (plus energy savings)
6. Negotiate Better Demand Rates
Work with a licensed PUCT broker to negotiate lower demand rates ($/kW) with REPs. Some REPs specialize in demand-optimized contracts for industrial accounts.
Savings potential: 10-30% reduction in demand charges (no operational changes required)
How to Find Demand Charges on Your Texas Electricity Bill
Demand charges are often buried in commercial electricity bills. Here's how to locate them:
What to Look For:
- • "Demand Charge" or "Capacity Charge" line item
- • Measured in kW (kilowatts), not kWh
- • Typically shows your peak demand for the month (e.g., "180 kW")
- • Multiplied by a rate (e.g., "$12.00/kW")
- • May be split into multiple categories: "On-Peak Demand," "Off-Peak Demand," "Ratchet Demand"
Tip: If you don't see demand charges on your bill, you may be on a small commercial rate schedule (under 50 kW) that doesn't include demand billing. Check your contract's Electricity Facts Label (EFL) to confirm.
Frequently Asked Questions
At what usage level do demand charges apply?
Demand charges typically apply to commercial accounts with peak demand above 50 kW. Smaller businesses (under 50 kW) are usually on "small commercial" rate schedules without demand charges. Check your contract or ask your REP to confirm.
Can I eliminate demand charges completely?
No, but you can minimize them. Demand charges exist because utilities and REPs must maintain infrastructure to meet your peak usage, even if that peak only occurs briefly. The goal is to reduce your peak demand through load management, not eliminate the charge entirely.
How often is demand measured?
Demand is measured in 15-minute intervals throughout the billing period. Your utility meter records the average kW usage during each 15-minute window, and the highest value becomes your billed demand for the month.
Do all Texas REPs charge demand the same way?
No. Demand rates ($/kW) and structures (simple, ratchet, TOU) vary significantly between REPs. Some REPs specialize in demand-optimized contracts with lower demand rates but slightly higher energy rates. Always compare the total cost (energy + demand) when evaluating REP offers.
Ready to Reduce Your Demand Charges?
Demand charges can represent 30-70% of your Texas commercial electricity bill. Power My Business helps you analyze your demand profile, negotiate better demand rates with REPs, and implement load management strategies to reduce costs.