The 15-minute maximum demand is the highest value of average electrical power measured in any 15-minute interval of the metering period. It is compared with the reserved capacity, i.e. the power that the customer has agreed with the distributor.
Why it matters
Electricity distribution charges depend not only on the amount of energy but also on the agreed reserved capacity. Exceeding the agreed power is charged, even for a short peak, for example when several machines start up at the same time. Individual peaks can therefore raise costs significantly.
How to reduce peaks
First you need to see the peaks: 15-minute data from the main meter and from sub-meters will show when and why they occur. They are then prevented by organisational measures (staggering the start-up of furnaces and compressors) or technical ones (load shedding). In a monitoring system, load shedding is used only where it is explicitly permitted, because it interferes with operations.
Example from manufacturing
In the morning, curing ovens, welding lines and compressors start up at the same time. The 15-minute power rises above the agreed value. The Energy Infra Scan platform displays the running 15-minute maximum against the reserved capacity and warns of an approaching breach, so that action can be taken in time.
Frequently asked questions
What is reserved capacity?
The electrical power that the customer has agreed with the distributor. In more recent regulations, the term reserved capacity is also used.
How is the 15-minute maximum measured?
The meter continuously calculates the average power in 15-minute intervals. The highest value in the metering period is the 15-minute maximum demand.