Tool
Interval data analyzer
Open the 15-minute data from your smart meter and see your peak demand, when it happens, how rarely you are near it, your load factor and what the building draws overnight. Your file stays on your computer.
An interval data analyzer reads a smart meter’s 15-minute or hourly readings and shows when a building’s demand peaks, how steady its load is and what runs overnight. In the modelled office below, demand peaked at 179.2 kW but stayed within 10% of that peak for only 143 hours of the year, with a 42% load factor.
Source: Interval analysis engine v1.0.0, modelled sample · 2026-11-11
Your file is not uploaded. This page reads it with your browser and does every calculation on your computer. Nothing is sent to this site or anyone else, and nothing is kept once you close the page.
The sample is a year of 15-minute readings generated from this site’s illustrative office load shape, with more cooling in summer, quiet weekends and a few short spikes. It is a model for showing what the tool does, not a measured building.
What interval data is
A monthly bill reports one number for energy and, on a demand-metered account, one number for the highest demand. The meter knows far more. A smart meter records how much electricity flowed in every short period, commonly 15 minutes, so a year of data holds about 35,000 readings. That record is what shows when a building uses power: the hour the peak is set, whether the load drops at night and at weekends, and whether one month’s demand charge came from a single unusual afternoon.
Most utilities let a customer download it from their online account. Many offer it in the Green Button format, built on the North American Energy Standards Board’s Energy Services Provider Interface standard, as a CSV spreadsheet or an XML file, often behind a button labelled “Green Button” or “Download My Data”. Pick the longest period on offer, ideally twelve months, so every season is in it. If there is no download, the utility’s business service team can usually supply interval data for the meter; our guide to getting interval data covers how to ask.
What the numbers mean
- Peak demand is the highest rate of draw in any interval, in kW. On many commercial rate schedules it sets the demand charge for the month, which is why one bad 15 minutes can cost as much as days of energy. How demand charges work.
- Hours near the peak is how long the meter spent within 10% of its highest reading. When that is a few dozen hours a year, the peak comes from a handful of moments, and staggering equipment start-ups, changing a schedule or a controller can trim it without changing how the building runs.
- Load factor is average demand divided by peak demand. A low figure means a peaky account where demand charges matter most; a high one means steady use where the energy price carries the cost. The load factor calculator does the same sum from a bill.
- Base load is the demand the building almost never drops below (the 5th percentile). Compared with the weekday daytime average, it shows how much runs when nobody is there.
What to do with the result
Look at the ten highest intervals first. If they fall on a few days, find out what happened then: a chiller and a kitchen starting together, a test of backup equipment, a charging schedule. Then check how your utility measures billed demand, because some schedules use only certain hours, carry a ratchet from earlier months or bill on the grid’s peak rather than yours. The demand charge and ratchet calculator models a ratchet once you know the rule.
The formulas
kW in an interval = kWh in the interval × 60 ÷ interval minutes peak demand = the highest kW in any interval average demand = total kWh ÷ hours of readings load factor = average demand ÷ peak demand base load = 5th percentile of interval kW hours above ceiling = intervals above (peak × (1 − cut)) × interval minutes ÷ 60 value of a cut = Σ over months of (that month’s peak − ceiling, if above) × your $/kW
Limits
- It reads; it does not bill. It never estimates a bill and quotes no prices. The only dollar figure is your own demand charge multiplied by kW.
- It uses the meter’s clock. Times are the file’s own. Weekends are Saturday and Sunday; public holidays are not separated.
- Files differ. If a file cannot be read, the page says why. Gaps, repeated times and readings of energy sent to the grid are reported, not hidden.
Common questions
- What is interval data?
- Interval data is the record a smart meter keeps of how much electricity flowed in each short period, usually every 15 minutes, sometimes every 5, 30 or 60. A month of 15-minute data has close to 3,000 readings, against one total on the bill, so it shows when the building uses power and not only how much.
- How do I download my interval data?
- Sign in to your utility account online and look for a usage page with a download option, often labelled Green Button or Download My Data. Choose the longest period offered, ideally 12 months, at the shortest interval, and save it as CSV or XML. If the account has no download, ask the utility’s business service team for interval data for the meter.
- What is a good load factor for a business?
- Load factor is average demand divided by peak demand. Below about 40 percent the account is peaky and demand charges tend to be a large share of the bill; above about 60 percent the load is steady and the energy price matters more. Neither is good or bad in itself; it says which part of the bill is worth working on.
- Does my file get uploaded anywhere?
- No. The page reads the file with your browser and does every calculation on your computer. Nothing is sent to this site or anyone else, and nothing is stored once you close the page.
Send a bill, with the interval file if you have it, and a person will check the rate schedule and demand structure against it. Nobody calls unless you ask.