Commercial Demand Charge Calculator
Demand charges are 20-40% of a commercial electricity bill but most calculators hide them. This tool shows you exactly how much demand is costing your business, and what reducing your peak kW would save.
15-min average max
US Average commercial: 13.92c/kWh
US Average typical: $15/kW
Your estimated monthly commercial bill
Office (10,000 sqft) in US Average at 12,000 kWh / 85 kW peak.
Line-item breakdown
Energy charge
12,000 kWh × 13.92c
$1,670
Demand charge
85 kW × $15/kW
$1,275
Fixed customer charge
Monthly meter / service
$25
Taxes (state + local)
~8% on energy + demand + fixed
$238
Monthly total
$3,208
Demand share of bill
40%
of your total bill
Annual bill$38,496
Annual demand$15,300
Effective $/kWh26.73c
vs nominal rate+92%
Load factor: 0.19 — very peaky — demand reduction is high-leverage
What if you reduced peak demand?
Demand charges scale linearly with your peak kW. Every kW shaved off the peak saves $15/month → $180/year. Here's the math at three reduction levels.
Reduce peak 10%
85 kW → 77 kW
$1,652/yr
$138/month
Reduce peak 20%
85 kW → 68 kW
$3,305/yr
$275/month
Reduce peak 30%
85 kW → 59 kW
$4,957/yr
$413/month
Battery storage payback (illustrative)
A battery system sized to shave 17 kW (20% of your peak) costs roughly $27,200 installed ($800/kW + $400/kWh × 2-hr discharge). Annual demand savings: $3,060.
Doesn't include ITC (currently 30% for commercial storage), state incentives, depreciation, or the value of resilience / backup power during outages. Real payback typically 30-50% faster with incentives.
Payback (no incentives)
8.9
years
How to actually cut peak demand
Five approaches ordered by capital intensity. The first three are operational changes (low or no capital); the last two are capital projects.
Stagger equipment startups
OperationalIf multiple motors / compressors / chillers start within the same 15-min window, their starting current stacks into your billing peak. Sequencing startups 5-10 min apart can drop measured peak 10-20% with zero capital. Easiest win for any business with 3+ large motor loads.
Pre-cool / pre-heat before peak windows
OperationalMost utilities define peak as 1-7pm summer weekdays. Cooling the building to setpoint by 12:30pm and then letting it drift 2°F means your AC runs minimally during the peak window. Buildings with thermal mass (concrete, masonry) hold pre-cooled state for hours. 5-15% demand reduction without changing comfort.
Automated demand response programs
OperationalMost utilities pay you to reduce demand during grid emergencies (5-20 events per summer). Enrollment is free, equipment grant often covers automation costs. Typical payment: $50-200/kW-year of curtailable load. PG&E ADR, ConEd CSRP, Eversource ConnectedSolutions, OG&E SmartHours all fit this pattern.
LED + smart-control retrofit
Capital ($)Lighting is typically 15-30% of commercial peak demand. LED retrofit cuts lighting load 60-70%, and occupancy sensors / daylight harvesting cut another 20-30%. Combined peak reduction: 12-25%. Payback 2-4 years on a typical 10,000 sqft facility, faster with utility rebates.
Battery storage for peak shaving
Capital ($$$)Battery discharges into the building during the 1-2 hour daily peak window, then recharges overnight. Sizes typically 50-500 kW / 100-1000 kWh for small-to-medium commercial. Cost roughly $1,200-$1,800/kWh installed. ITC currently 30%. Payback 5-12 years depending on demand rate and utility incentives. Adds resilience as a bonus.
On-site solar (limited demand benefit)
Capital ($$$)Solar reduces ENERGY charges materially but only reduces DEMAND charges if the peak window aligns with sun hours. For most commercial customers with 5-7pm peaks, solar offsets little demand. Combining solar with battery is much more effective for demand reduction than solar alone.
Related tools for businesses
Methodology and assumptions
Demand-charge tariffs vary widely by utility and even by rate class within a utility. This calculator is a directional estimate. For RFP-level accuracy, request your utility's exact tariff schedule and your last 12 months of interval data.
State commercial rate ($/kWh)
EIA Electric Power Monthly Table 5.6.A, commercial sector average. Current data: March 2026 (US commercial average 13.92c/kWh). Refreshed monthly via our automated EIA pipeline.
Demand charge rate ($/kW-month)
Defaulted by state based on a midpoint of large IOU tariffs in that state. Range: $7-$28/kW depending on state. California ($24), Hawaii ($28), Northeast ($17-22) sit at the high end. Texas, Louisiana, Pacific Northwest cluster $8-12. Cross-referenced against OpenEI URDB and individual utility tariff sheets.
Business profiles
kWh and peak kW values derived from EnergyStar / CBECS (Commercial Buildings Energy Consumption Survey) typical-property profiles, adjusted to medians within each property type. Custom mode lets you enter your own values from your bill or interval data.
Fixed customer charge
Set to $25/month, the US-typical small-commercial customer charge. Larger commercial accounts have higher fixed charges ($50-200/month); industrial accounts can have multi-hundred-dollar service charges. Adjust mentally if your business is significantly larger or smaller than the preset.
Battery payback math
Battery cost set to $1,600/kW-shaved, based on a 2-hour discharge battery at $800/kW power + $400/kWh energy density. Excludes the federal Investment Tax Credit (currently 30% for commercial battery storage), state-level incentives (CA SGIP, NY NYSERDA, MA SMART), and any utility demand-response payments. Real payback is typically 30-50% faster with incentives factored in.
Tax and fee assumptions
8% applied to energy + demand + fixed as a US-blended commercial tax rate. Actual rates vary 0-15% depending on state and local jurisdiction. Some states exempt commercial electricity from sales tax (Texas, Oregon); others apply full sales tax (Florida, NY) plus utility-specific franchise fees.
Frequently Asked Questions
What is a demand charge on an electricity bill?+
A demand charge is a fee based on your peak 15-minute or 30-minute average power draw in kilowatts (kW), measured separately from your total kWh energy usage. Where the energy charge bills you for how much electricity you used, the demand charge bills you for how fast you used it at the highest point in the billing period. Typical commercial demand charges run $5-$30/kW-month depending on utility. A business with 100 kW peak demand at $15/kW pays $1,500/month in demand charges before touching the per-kWh energy charge.
How much of a commercial electricity bill is demand charges?+
Demand charges typically represent 20-40% of a commercial electricity bill, varying by load shape. A business with steady consumption (data center, 24/7 retail, school) has a high load factor (kWh used vs peak kW × hours-in-month) and lower demand-share percentage. A business with peaky consumption (restaurant lunch rush, hot summer afternoon retail, warehouse with morning conveyor startup) has low load factor and demand can hit 40%+ of the bill.
Do residential customers pay demand charges?+
Almost never. US residential rates are nearly always energy-only ($/kWh), with no demand component. Some utilities (Salt River Project Arizona, certain rural co-ops) have experimented with residential demand charges but adoption is rare. The reason: residential metering historically didn't capture 15-minute peaks. Modern smart meters can, but the utility industry has been reluctant to confuse consumers with two-part bills.
What is a 'load factor' and why does it matter?+
Load factor = monthly kWh ÷ (peak kW × hours in month). It's the ratio of your average power draw to your peak. A load factor of 1.0 means you used your peak kW every hour of the month (impossible, but the theoretical maximum). 0.5 means you used half your peak on average. 0.2 means you have brief, intense peaks. Low load factors are expensive on demand-charge tariffs because you're paying for grid capacity you barely use. Businesses with load factor below 0.3 should aggressively pursue demand reduction.
What's the cheapest way to reduce my demand charge?+
Operational changes (zero or near-zero capital): (1) stagger equipment startups 5-10 minutes apart to avoid stacking starting currents into the same 15-minute window, (2) pre-cool / pre-heat the building before utility peak hours so the HVAC system can coast through, (3) enroll in your utility's automated demand response program for 5-20 emergency events per year (pays $50-200/kW-year of curtailable load). These three combined typically reduce peak demand 15-25% with no capital spend. After that, capital options (LED retrofit, battery storage) extend the savings but with longer payback.
Does solar reduce demand charges?+
Solar reduces energy charges substantially but reduces demand charges only modestly, because most commercial peaks happen between 4pm and 7pm when solar production has declined. A typical office or warehouse with 5pm peak gets perhaps 10-20% demand reduction from solar alone. Combining solar with battery storage is much more effective: the battery discharges into the building during the brief peak window, shaving 30-50% of demand. For demand-charge reduction specifically, batteries are the high-leverage investment; solar is for energy charge reduction.
Are demand charges going away?+
Not on commercial tariffs. Demand charges fundamentally reflect the cost of building grid capacity to serve peaks, and that cost is real and growing as electrification (EV chargers, heat pumps, data centers) increases peak load. If anything, demand charges are spreading: more utilities are introducing time-of-use demand charges (different $/kW rates depending on time of day) and pushing residential demand charges in EV-heavy rate classes. Strategic peak-shaving is becoming a core part of commercial energy management, not an optional add-on.
