ATCO takes the highest of the applicable criteria across transmission, distribution and service charges. That single design choice makes an unmanaged peak more expensive here than in neighbouring territory.
Full detail below.
Most operators assume demand billing works the same way wherever they are. It does not. The Utilities Consumer Advocate describes ATCO Electric as following a broadly similar approach to other demand-billing distributors, except that it uses the highest of the applicable criteria for the transmission, distribution and service charges, rather than assigning different determinants to different lines.
The practical effect is concentration of risk. Under a tariff that bills one line against your metered peak and other lines against a contracted level, a bad interval hits one line. Under a highest-of structure, the same bad interval can influence considerably more of the invoice.
| ATCO Electric | FortisAlberta | |
|---|---|---|
| Determinant approach | Highest of the applicable criteria, applied across transmission, distribution and service charges | System usage against highest metered demand; capacity charges against contracted demand |
| Rate minimum | 5 kW | 3 kW |
| Ratchet provisions | Present in some rate designs | Present in some rate designs |
Source: Utilities Consumer Advocate, Understanding demand charges. Billing determinants and rate minimums are set in each distributor's approved tariff and change over time. Confirm the figures on your current rate schedule before relying on them.
Counterintuitively, the tougher structure makes the case for shaving stronger rather than weaker. If a single criterion is feeding several charge types, every kilowatt removed from the binding figure is worth more than it would be on a tariff that isolates the exposure. The prerequisite is establishing which criterion is actually binding on your account, which is an interval data question rather than a tariff question.
This is the most common reason operators in this territory go looking for answers. The usual explanations are a tariff rate change, a new peak entering a ratchet window, or a shift in which criterion is binding. Monthly totals cannot distinguish between them. The interval record can, and your distributor will provide it on request.
ATCO Electric applies a similar approach to other demand-billing distributors, with one important difference: it uses the highest of the applicable criteria across the transmission, distribution and service charges rather than applying different determinants to different lines. A rate minimum of 5 kW applies.
Structurally, ATCO's approach carries more exposure. Because the highest of the criteria is applied across all three charge types rather than only to one, a single high reading or a ratcheted historical peak can influence more of the invoice at once. The rate minimum is also higher at 5 kW against 3 kW.
Rate changes, a new peak entering a ratchet window, or a change in which criterion is binding on your account are the usual causes. Because ATCO takes the highest of the applicable criteria, a change that would only affect one line under another tariff can affect several here.
Yes, where the binding criterion is your metered peak. Because that criterion feeds multiple charge types on this tariff, a successful shave can be worth more per kilowatt removed than on a tariff that isolates it to a single line. Whether that applies to your account depends on which criterion is currently binding.
5 kW, according to the Utilities Consumer Advocate, against 3 kW in FortisAlberta territory. Billing demand does not fall below that floor regardless of actual usage.
