Demand charges can represent 30 to 70 percent of a commercial electricity bill, yet most business owners do not fully understand how they work. This guide explains what demand charges are, how they are calculated, and how solar and batteries can dramatically reduce your peak demand costs.

If you own or manage a business in Colorado, you are almost certainly paying demand charges on your electricity bill. Unlike residential bills, which primarily charge for the total amount of energy you use (measured in kilowatt-hours), commercial electricity bills include a separate charge for the peak rate at which you use energy (measured in kilowatts). This peak usage charge, called a demand charge, can be shockingly large and is one of the most overlooked opportunities for cost reduction.

Understanding demand charges is the first step toward controlling them. And for many businesses, solar panels and battery storage offer the most effective tools to slash these costs.

What Are Demand Charges?

Demand charges are a fee based on the highest amount of electricity your business draws from the grid at any point during a billing period. Think of it this way: your energy charge (per kWh) reflects how much total electricity you use in a month, while your demand charge (per kW) reflects the maximum rate at which you used it.

Utilities use demand charges because the grid must be built to handle peak loads. If your business draws 100 kW of power for just 15 minutes on a hot afternoon when all your HVAC systems and equipment are running simultaneously, the utility needs infrastructure capable of delivering that 100 kW. That infrastructure costs money whether your peak lasts 15 minutes or 15 hours.

How Demand Charges Are Calculated

Your electric meter records your power draw in 15-minute intervals throughout the billing period. The single highest 15-minute average becomes your peak demand for the month. Your demand charge is then calculated by multiplying that peak kW reading by the per-kW demand rate.

Example: If your peak demand is 85 kW and Xcel Energy's demand rate is $15.50 per kW, your demand charge for the month is 85 x $15.50 = $1,317.50. That charge appears on your bill regardless of whether that peak lasted 15 minutes or happened just once during the entire month.

Some utility rate structures also include a "ratchet" provision. This means your demand charge for a given month might be based not on that month's actual peak, but on a percentage (often 80 to 90 percent) of your highest peak from the previous 12 months. Ratchet clauses mean a single spike in demand can elevate your bills for an entire year.

Why Demand Charges Are 30-70% of Commercial Bills

Most business owners are surprised to learn how much of their electricity bill comes from demand charges rather than actual energy consumption. For many Colorado businesses, demand charges represent the single largest line item on the bill.

The exact percentage depends on your business type and usage pattern:

• Offices and retail: Demand charges typically 30 to 40 percent of total bill. These businesses have moderate, relatively steady loads.
• Restaurants: Demand charges 40 to 50 percent. Cooking equipment, refrigeration, and HVAC create pronounced peaks during meal rushes.
• Manufacturing and warehouses: Demand charges 50 to 60 percent. Heavy machinery startup creates sharp demand spikes.
• Cold storage and data centers: Demand charges up to 70 percent. These facilities have high baseline loads with occasional spikes from compressor cycling or backup systems.

The more "peaky" your electricity usage pattern, the higher the proportion of your bill that comes from demand charges. Businesses that use a lot of electricity in short bursts pay disproportionately more than businesses with steady, flat consumption profiles.

Xcel Energy Commercial Rate Structures

Along Colorado's Front Range, most commercial customers are served by Xcel Energy under one of several commercial rate schedules. The most common are:

• Schedule C (Commercial): For small commercial customers with demand under 25 kW. Demand charges are lower but still present.
• Schedule SG (Secondary General): For medium commercial customers with demand between 25 and 1,000 kW. This is where demand charges become a major factor, with rates often exceeding $14 to $18 per kW.
• Schedule PG (Primary General): For large commercial and industrial customers with demand above 1,000 kW. Demand rates vary but the absolute dollar amounts are significant.

Xcel also offers time-of-use (TOU) rate options for commercial customers, which add another dimension: demand charges may vary based on when your peak demand occurs. On-peak demand (typically weekday afternoons) carries higher rates than off-peak demand. Understanding your rate schedule is essential for optimizing your demand charge reduction strategy.

Strategies to Reduce Demand Charges

The good news is that demand charges, once understood, can be actively managed and reduced. Here are the most effective strategies for Colorado businesses.

Strategy 1: Solar Peak Shaving

Commercial solar panels produce the most electricity during peak sun hours, which often coincide with peak demand periods for many businesses. When your solar system is producing 40 kW during the afternoon and your building is consuming 85 kW, your net draw from the grid drops to 45 kW. That 45 kW becomes your demand measurement instead of 85 kW, potentially cutting your demand charge nearly in half.

Solar alone does not eliminate demand charges entirely because your peak demand might occur on a cloudy day, in the evening, or during a period when solar production does not align with your peak load. But for businesses with daytime-heavy consumption patterns, solar can significantly flatten the demand curve.

Strategy 2: Battery Peak Shaving

Battery storage is the most powerful tool for demand charge reduction. A battery system charges during low-demand periods (or from excess solar production) and discharges during peak demand periods to reduce your draw from the grid. Modern commercial battery systems can be programmed to automatically activate when your demand approaches a target threshold.

For example, if your goal is to keep demand below 50 kW, the battery system monitors your real-time consumption. When demand rises toward 50 kW, the battery begins discharging to supplement grid power, keeping your metered demand at or below the target. This approach works regardless of weather, time of day, or solar production.

Tesla Powerwall and Enphase battery systems both support commercial peak shaving configurations. The ROI on battery systems is often fastest when demand charges are a large portion of your bill, because the savings are immediate and consistent.

Strategy 3: Load Management

Load management means scheduling your electricity-intensive operations to avoid simultaneous peaks. Simple adjustments can make a significant difference:

• Stagger the startup of heavy equipment rather than turning everything on at once
• Pre-cool or pre-heat your building during off-peak hours
• Schedule EV charging for overnight or off-peak periods
• Use smart building controls to limit simultaneous HVAC compressor operation
• Shift laundry, ice-making, or water heating to off-peak hours

Load management alone can reduce demand charges by 10 to 20 percent with minimal investment. Combined with solar and battery storage, the reductions can be dramatic.

Strategy 4: Solar Plus Battery (The Optimal Combination)

The most effective demand charge reduction strategy combines solar panels with battery storage. Solar reduces daytime demand peaks, batteries cover peaks that occur outside of solar production hours or on cloudy days, and the battery charges from excess solar production during midday when your building may not need all the solar power being produced.

This combination can reduce demand charges by 40 to 60 percent or more, depending on system sizing and your consumption pattern.

ROI Examples for Colorado Businesses

To illustrate the financial impact, here are two examples based on typical Colorado commercial electricity profiles:

Example 1: Small Office Building

• Monthly electricity bill: $2,800
• Demand charges: $1,050 (37% of bill)
• Peak demand: 72 kW
• Solution: 40 kW solar system
• Estimated demand reduction: 25 kW (peak drops to approximately 47 kW)
• Monthly demand charge savings: approximately $390
• Combined with energy savings: total monthly savings of approximately $950

Example 2: Manufacturing Facility

• Monthly electricity bill: $9,500
• Demand charges: $5,225 (55% of bill)
• Peak demand: 320 kW
• Solution: 150 kW solar system + 100 kWh battery storage
• Estimated demand reduction: 120 kW (peak drops to approximately 200 kW)
• Monthly demand charge savings: approximately $1,860
• Combined with energy savings: total monthly savings of approximately $4,200

When you factor in the federal solar tax credit and MACRS depreciation, the payback period for commercial solar systems designed to reduce demand charges is typically 4 to 7 years, with the system continuing to produce savings for 25 years or more.

Next Steps for Your Business

The first step in reducing your demand charges is understanding them. Pull out your most recent commercial electricity bill and identify the demand charge line items. Note your peak demand in kW and the per-kW rate. Calculate what percentage of your total bill comes from demand charges. If it is 30 percent or more, you are an excellent candidate for solar and battery demand charge reduction.

ProGreen Solar specializes in commercial solar installations across Colorado's Front Range, with deep expertise in designing systems that target demand charge reduction. We analyze your utility rate structure, consumption patterns, and demand profile to design a system that maximizes your financial return.

Contact us for a free commercial solar assessment. We will review your electricity bills, identify your demand charge reduction opportunity, and provide a detailed proposal with projected savings and ROI.

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