We offer a complete line of Energy Management, Electrical Meters and Motioning Tools.
Electrical energy is billed to customers typically based on the volume of their usage.
For domestic and small retail customers the charges in North America are usually based only on consumption in kilowatt hours, kWh. For these customers, up to a certain threshold, the more you use the more you pay based on a tariff which may vary by time of day and by season (summer or winter tariff).
For larger customers there is an additional charge based on their peak demand measured in kilowatts, kW as well as the consumption charge in kWh. The larger customers pay less per kWh than small customers but pay the demand charge in addition.
The peak demand charge is based on the maximum amount of power used in a 15 minute period at any time in a month and this maximum peak rate is applied for the whole month even though the customer may have little if any consumption during part of this time (for some utilities for some very large customers the period may be longer than1 month).
When a conventional electric motor is started from cold it can take up to 7 times its normal running current for a few seconds in order to start the motor. Typically on a Monday morning in a manufacturing facility someone starts multiple motors, turns on lights, water heaters, coffee machines etc. all in a short period of time. The electrical utility has to provide extra generating capacity to cope with this demand so they charge customers based on their peak demand.
It is fairly obvious that if the switching of electrical loads were to be staggered over a longer period then the peak demand can be lowered. Surprisingly many N. American companies have done little if anything to mitigate these costs which can be substantial.
Tools are available for monitoring and control of peak demand levels
Many North American utilities now charge larger customers a power factor charge as a third element of the bill. This charge occurs when the factory load is largely inductive due to the presence of motors and transformers especially when these are lightly loaded and a lagging power factor occurs
The first step in control of energy use is to measure where and how it is being used. This requires the installation of meters, not just at utility service entrance point but at various levels throughout an organization whether by department, production line or individual machine (Janitza products). Once data has been collected and analyzed steps can be taken to control and reduce usage and demand and monitor each step as improvements are implemented.
Typical Steps include;
Conventional motor starters can be replaced with VFD’s which require much lower starting currents; high efficiency motors can result in substantial energy savings particularly when sized for actual loads. In North America there has been a tendency to use motors which are larger than needed for actual loads and this leads to motor inefficiency and extra use of electrical power and poor power factor. Turn off loads such as fans, lights compressors, water heaters, chillers when they are not actually needed either manually or with timers. Install suitably engineered power factor control equipment.