Every company with semi-direct or indirect metering already possesses one of the most valuable documents about its own energy use, yet most have never opened it. This is the 15-minute load profile: a record of the average power demand during every quarter-hour of the month. Your electricity bill tells you how much energy you consumed. The load profile tells you how you consumed it, and that is where virtually all potential savings can be found.
The data are stored in the electricity meter and held by the distribution system operator. They are generally available to customers through the operator’s online portal or upon request, usually in a tabular format suitable for further analysis. Companies with their own energy monitoring systems may have access to even more detailed information, but the official 15-minute data are more than sufficient for the first serious conclusions.
The billing peak demand is the highest average power recorded during any 15-minute interval in the month, and it is charged through the demand component of the electricity bill. The first question is therefore: how many peaks occur close to the maximum, and when do they happen?
When the maximum appears only a few times per month in recognisable situations, such as the simultaneous start-up of large machines, the activation of cooling equipment at the beginning of a shift, or the overlapping of several processes, the company is paying for power caused by scheduling rather than by an actual continuous need.
These peaks can be reduced through better organisation, load sequencing, and automated control. Where these measures are not sufficient, a battery energy storage system can absorb the short-term peaks.
The second diagnosis is the baseload: the level below which demand never falls, even at night, during weekends, or on public holidays. This is the power the facility continues to draw while no one is working.
Baseload can reveal compressors maintaining pressure because of leaks in the installation, ventilation systems operating unnecessarily, electric heaters, lighting, and equipment left idling. In many industrial facilities, baseload accounts for a surprisingly large proportion of total monthly energy consumption. It can often be reduced through the least expensive measures available: switching equipment off and repairing faults.
The third aspect to examine is the shape of a typical working day: when demand begins to rise, where it reaches a plateau, and how the different shifts compare.
For any company considering a solar power plant, this is the key graph. The profitability of on-site solar generation depends largely on how closely electricity consumption coincides with daylight and solar production hours.
The load profile immediately shows how much of the future solar production could be consumed on site and how much would be exported to the grid. It therefore provides a far more reliable basis for sizing a solar power plant than any general assumption.
In essence, the 15-minute load profile is an X-ray of a company’s energy behaviour. It can be analysed in a single afternoon, costs nothing to obtain, and every serious decision concerning power demand, battery storage, solar generation, or electricity tariffs should begin with it.
