Peak demand profiling is the analysis of when, how, and why a site reaches its highest electrical demand. It uses time-series data (typically kW/kVA at 15–30-minute intervals) to map demand peaks across days, weeks, and seasons and to identify the specific loads—such as EV chargers, HVAC, or industrial equipment—that drive them.
Why Peak Demand Profiling Matters in EV Charging
Peak demand drives electrical constraints and operating costs. Profiling helps site owners, fleets, and CPOs:
– Reduce demand charges by understanding peak drivers and shifting load
– Validate the required import capacity and transformer headroom
– Configure load management targets based on real usage, not assumptions
– Avoid nuisance trips by predicting high-risk peak windows
– Plan expansions (more charge points, higher power) with evidence
– Improve utilization without breaching a maximum site demand limit
How Peak Demand Profiling Works
A typical profiling workflow includes:
– Collect demand data from interval metering at the main incomer and/or sub-meters
– Separate demand into load groups (EV charging, building loads, production loads)
– Identify peak events (top 1%, daily peaks, monthly maxima)
– Analyze peak timing patterns (morning ramp, shift changes, evening peaks)
– Correlate peaks with operational events (fleet returns, HVAC cycles, tariff windows)
– Produce actionable outputs: peak windows, headroom estimates, and control rules
Data Sources Used
Peak demand profiling commonly uses:
– Utility smart meter interval data
– LV panel meters (CT-based sub-metering for charger feeders)
– CPMS data (charger power, active sessions, throttling events)
– Building Management System (BMS) data for HVAC and other loads
– Calendar/operations data (shift schedules, delivery cycles, occupancy)
What Peak Demand Profiles Typically Reveal
A well-built profile can identify:
– Simultaneity factor: how often chargers run together at high power
– Peaks caused by synchronized charging starts (e.g., 18:00 fleet return)
– Non-EV peaks dominating demand (HVAC or production equipment)
– Opportunities for load shifting to off-peak hours
– Required headroom and the true binding constraint (breaker, cable, transformer, tariff)
– Whether peak shaving needs automation or simply operational changes
Strategies Enabled by Peak Demand Profiling
Insights from profiling are used to implement:
– Dynamic load balancing (real-time limit control)
– Staggered start schedules for fleet or workplace charging
– Peak shaving using batteries or controlled throttling (site-dependent)
– Priority rules (critical vehicles first, early departures first)
– Tariff optimization with time-of-use (TOU) charging windows
– Phase-aware distribution to reduce per-phase overload
Key Benefits
– Lower operating costs by reducing peak-driven charges
– Higher site reliability and fewer overload events
– Better charging performance with smarter, less conservative power limits
– Stronger business cases for expansion and grid upgrades
– Clear reporting for stakeholders (landlords, finance, utilities)
Limitations and Practical Considerations
– Requires clean data (time sync, gap handling, consistent intervals)
– Demand definitions vary by utility (rolling window vs fixed interval)
– CPMS data alone may miss non-EV loads without sub-meter integration
– Short profiling periods can be misleading (seasonality, atypical weeks)
– Needs ongoing updates when fleets, tariffs, or building loads change
Related Glossary Terms
Peak Demand
Peak Demand Logging
Interval Metering
Load Profile
Load Measurement
Demand Charges
Maximum Demand
Maximum Site Demand Limit
Load Management
Load Shifting
Peak Shaving