Many commercial electricity tariffs bill not only for energy in kWh but also for peak demand in kW, measured over a short interval each month. A 22 kW DC charger like the EV-RHDC30K-L can add up to about 22 kW to that peak if it runs while the building is busy. Because its power is modest, the demand impact is far smaller than a high-power DC station, and load management can reduce it further.
Key Takeaways
- Demand charges bill peak kW, not just kWh.
- A 22 kW unit adds a modest, controllable peak.
- Load management and scheduling limit demand impact.
- Check your own tariff and interval data first.
How Demand Charges Work
Utilities with demand tariffs record the highest average power drawn over a short window, often 15 or 30 minutes, during the billing period. That peak is multiplied by a demand rate per kW. One busy half-hour can set the demand charge for the whole month. Tariff structures vary widely, so read your own tariff or ask your utility.
A Worked Example
The figures below are hypothetical, to show the mechanism. Use your own tariff’s rates.
| Item | Without charger | With charger at the building’s peak |
|---|---|---|
| Building peak demand | 60 kW | 82 kW |
| Demand rate (example) | $15 per kW | $15 per kW |
| Monthly demand charge | $900 | $1,230 |
| Energy for charging, 800 kWh at 14.53 cents (U.S. commercial average, EIA, July 2026) | — | about $116 |
In this example the demand charge, not the energy, is the larger extra cost. If the charger only runs when the building is quiet, the peak may not rise at all.
Ways to Limit Demand Impact
- Load management: cap charger power when building load is high, using OCPP charging profiles.
- Scheduling: encourage fleet charging outside the building’s busiest hours.
- Pricing: set public tariffs that reflect peak costs, or offer cheaper off-peak rates.
- Tariff choice: ask the utility whether an EV-specific or time-of-use commercial tariff is available.
- Right-sizing: a 22 kW unit already avoids the large peaks of high-power chargers.
Read why DC fast charging is expensive and whether charging is profitable for the bigger cost picture.
Measuring Before You Decide
Look at 12 months of interval data from your utility to see when the building peaks. Place the charger’s busiest hours outside those peaks if possible. After installation, compare monthly peaks before and after and adjust load limits. If the charger serves your own fleet, the cheapest kWh is often the one delivered late in the evening, when the building has emptied and the demand meter is no longer close to its monthly high.
The EV-RHDC30K-L is a floor-standing DC charger rated at 22 kW continuous, with OCPP 1.6J for remote management and charging profiles, a single tethered CCS1 connector, IP54 enclosure and a 3-year warranty.
Frequently Asked Questions
What is a demand charge?
A fee based on your highest average power draw over a short interval in the billing period, multiplied by a rate per kW.
Will a 22 kW DC charger raise my demand charge?
It can by up to about 22 kW if it runs during your building’s peak. Load management can prevent that.
Can I avoid demand charges completely?
Not always, but scheduling, load management and tariff choice can reduce them.
Related Reading
- Why Is DC Fast Charging So Expensive?
- Is an EV Charging Station Business Profitable?
- How Much Do Commercial EV Chargers Cost?
- What Is EV Charger Load Balancing? How Multi-Charger Sites Share Power
