Our demand charges went up.
On a demand tariff, part of the bill is set by the highest demand the facility reaches in the billing period. One busy interval can decide it, and the energy used through the rest of the month does not change it.
How One Interval Sets the Charge
The utility's meter records demand in short intervals, often 15 minutes long. The highest interval of the billing period is the one the demand charge is read from.
- The peak is a moment
- A few loads starting together can set it: cooling units staging on a hot afternoon, kitchen equipment coming up to temperature, chargers connected as a shift ends.
- It can outlast the month
- Some tariffs carry a high peak forward into later bills. Your tariff sets that rule, and the determination reads it from your bills.
- New load moves it
- Chargers, heat pumps and electric kitchens raise the peak when they run during it. Whether they do is a question of timing, and the record shows it.
What Peak Determination Answers
- 01
Which intervals set your demand charges over the last 12 months, and when they happened.
- 02
The pattern behind them: the time of day, the day of the week and the season they fall in.
- 03
What each of those peaks cost on your tariff.
- 04
Where new load is coming, what it does to the peak, with and without control of when it runs.
What Answers It
Capacity Report
The base Peak Determination is added to: measured demand and headroom from 12 months of utility records. Engineer-reviewed and unsealed, so it is not submittable to an AHJ.
Peak Determination
The peaks that set your charges, what they cost on your tariff, and a charging overlay where chargers are coming.
What It Needs, and What It Does Not Promise
Peak Determination reads 12 months of interval data from your utility, which many utilities let an account holder download. There is no metered version: the charge is set by the utility's own meter, so the utility's record is the evidence.
It states what set each peak and what it cost. It does not promise a saving, because what you change after reading it is your decision.
Where This Comes Up
A restaurant group with one site out of line
The same menu and the same hours, and a different demand charge. The intervals show which morning every appliance came up to temperature together.
Cold storage after a hot summer
Refrigeration works hardest on the hottest afternoons. The peak intervals show whether they lined up with those days or with something else.
An office adding chargers to its garage
The overlay shows whether charging as staff arrive lands on top of the morning cooling ramp, and what it would do to the charge if it did.
Questions About Demand
- Why not meter the facility instead?
- The charge is set by the utility's meter across the whole billing period. Its own interval record is the exact evidence, and a 30-day recording of ours would only be a sample of it.
- Will this lower my bill?
- It shows what set the charge and what it cost, and it identifies the peaks that came from equipment timing you control. The saving depends on what you change.
- Can I get it without a Capacity Report?
- No. Peak Determination is added to a Capacity Report, because both read the same year of utility records and the report establishes the demand the analysis starts from.