Energy intervals and demand intervals are different
A file may show kWh consumed during each interval or average kW over that interval. To convert interval kWh to average kW, divide by the interval length in hours. For a 15-minute interval, 25 kWh corresponds to 100 kW. Do not simply label every numeric column demand. Confirm whether timestamps identify the start or end of the interval and how daylight-saving changes are represented. These details can change peak identification and cost allocation.
Validate before interpreting the pattern
Check duplicate timestamps, missing intervals, negative values, resets, meter multipliers, and account coverage. Reconcile the aggregate with billed consumption, allowing for documented billing-period boundaries and adjustments. Missing intervals should not silently become zero use. A graph can look smooth while concealing a unit error. Preserve the original file and record cleaning steps. If utility data access requires authorization, grant only the scope needed and keep the account identifiers out of public reports.
Connect patterns with operations and tariffs
Overlay occupancy, production, HVAC startup, charging, and equipment schedules. Look for unusual overnight use, concurrent loads, or seasonal changes, then confirm the cause with site staff. Apply the actual tariff intervals and demand rules to estimate cost effects. For indexed supply, calculate usage-weighted prices at the correct location and timestamps. A generic monthly market average does not substitute for the account’s interval exposure. Any load change should be verified after implementation rather than assumed from a chart alone.
Hypothetical schedule finding
A shop’s data shows 60 kW from midnight to 5 a.m. when staff believe the building is closed. An investigation identifies a control schedule issue, but essential refrigeration and security loads remain. If a verified change removes 10 kW for five hours on 20 nights, the energy reduction is 1,000 kWh. Demand savings require a separate check of whether the billed peak changed. The example illustrates a measurement process, not a promised percentage reduction.
Practical review checklist
- Verify account, units, duration, time zone, timestamp convention, multipliers, and reading status.
- Identify missing or duplicate records and reconcile total energy to the relevant billing period.
- Match observed patterns with actual operations before recommending equipment or schedule changes.
- Model tariff and supply effects separately, then verify outcomes using comparable post-change data.
Questions & answers
Can I obtain interval data from a monthly bill alone?
Usually not. Request the relevant meter data through the utility or authorized account-access process.
Why does daylight saving time matter?
Repeated or missing local hours can misalign data with prices, peaks, and schedules unless timestamp rules are handled correctly.
Sources & scope
Primary references reviewed October 15, 2026. These sources support the stated concepts; actual tariffs, program rules and signed agreements govern the account. Decision examples and operational worksheets are original educational analysis.
- DOE FEMP: Evaluating your utility rate options
Demand, ratchets, time-of-use rates, coincident peaks, and standby charges. - ENERGY STAR: Analyze benchmarking results
Peer comparisons, performance tracking, and score interpretation. - FERC: Wholesale electricity markets overview
Wholesale energy, capacity, and ancillary-service functions.