Augos Energy / Peak shaving and load shifting
Demand charges, explained
Peak shaving and load shifting, explained.
What curtailment and shifting do to a demand charge and a time-of-use bill, when each pays, and what Augos measures to show the result.
Augos is the energy back office for multisite businesses in South Africa: energy management software, bill verification and independent advisers, checking what every site should pay against the meter and the tariff.
Peak shaving
Hold the highest half-hour down.
On a demand tariff, one half-hour sets the demand charge for the month. Cutting non-critical load for a few minutes while a peak forms keeps that half-hour lower, and the charge with it.
Load shifting
Move work out of the peak window.
On a time-of-use tariff, energy in the peak window costs most. Work that can run at any time, such as pumping or milling, costs less in standard or off-peak hours.
Run it on the record
A peak, and the same day shifted.
One day of 30-minute demand
IllustrativeThe demand charge is set by the highest half-hour. Moving load that can wait lowers that half-hour; the energy used is the same, it just runs later.
Illustrative demand profile, not a customer. The same meter shows whether a change held the next peak down.
When does it pay?
Shaving pays when the demand charge is a large part of the bill and the peaks come from load that can wait. Shifting pays when the site is on a time-of-use tariff and some of its work is not tied to the clock. Neither pays if the load that sets the peak is the load that makes the product.
Check the tariff first: a site whose load has changed may do better on a different tariff, or with a lower notified maximum demand, before any load is moved. See tariff optimisation and power factor correction.
What Augos measures to show it
Demand every 60 seconds, rolled up to the 30-minute intervals the utility bills on. The time of use report shows how much energy falls in each window; with sub-meters on the main loads, the consumption breakdown shows which of them set each peak; and the same meter shows whether a change held the next peak down.
For the difference between planned and forced curtailment, read strategic and non-strategic load curtailment.
Free site assessment
Assess your measurement point and get a quote.
Tell us the site type, supply size and number of sites, photograph the measurement point, and we quote. Electricity now; water, gas and fuel next.
What it costs
One price per meter.
R450 a month per meter, ex VAT, covers every module. Managed bill verification is R145 a month per bill point, ex VAT. Tariff implementation is from R35,000, ex VAT.
Questions
What is the difference between peak shaving and load shifting?
Peak shaving cuts load for a short spell to hold the highest half-hour down, which lowers the demand charge. Load shifting moves work that can run at any time out of the peak time-of-use window into standard or off-peak hours, so the same work costs less.
What is notified maximum demand, and why does one spike matter?
Notified maximum demand is the capacity agreed with your supplier. On many tariffs, exceeding it raises the charges, and on some the higher figure carries forward for months. Holding the peak below it avoids that.
When does peak shaving pay?
When the demand charge is a large part of the bill and the peaks come from load that can wait a few minutes without affecting output, such as pumping, heating or refrigeration with thermal storage.
When does load shifting pay?
When the site is on a time-of-use tariff and some work can run outside the peak window without changing output.
How is this different from power factor correction?
Power factor correction reduces the reactive power that inflates kVA. Shaving and shifting act on the real load. Many sites look at both, on the same meter.
What does Augos measure?
Demand every 60 seconds, rolled up to the 30-minute intervals the utility bills on, so you see when each peak forms and whether a change held it down. With sub-meters on the main loads, you also see which of them set it.