Learn About Demand Rates

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What is a Load Controller?

How to Control Demand Use

 A load controller in layman's term is a “cruise control for your APS or SRP bill”.  A load controller (aka: “demand computer") is a microprocessor-based system that allows the end user to set the maximum amount of power used in measured time period. These time periods vary with each utility: SRP has a 30 minute average window and APS customers have a 60 minute time period. (For more detailed information on energy rates in AZ click here). 

   The demand charge is only in effect during on-peak hours: SRP (Summer): 1pm-8pm Mon-Fri      (Winter): 5am-9am 5pm-9pm Mon-Fri APS (all year) 3pm-8pm Mon-Fri Demand charges are only in effect during on-peak hours. During off-peak times, there is no demand charge and the cost of energy (kWh) is also lower. Shifting more high energy-using devices to off-peak times is a win - win - win for everyone. You get lower bills and the utilities can offset the cost of building peaker plants that are used only during the summer for the A/C loads in desert homes. Understanding how these rates work and making small changes to your lifestyle such as doing laundry and using hot water during off peaks times can make big changes in demand charges.  Pre-cooling your house four or five hours before on peak starts then raising the thermostat temperature “shifts” more of your usage to the more inexpensive off-peak times when demand is not being measured. How long you can go using no a/c during a hot day depends entirely on how much heat is coming into your home. We have products that can significantly reduce the heat coming through the ceiling. More>>>>    


How does a Load Controller work? A load controller is connected to the following loads in your home: Air conditioner(s) or heat pump(s) Electric hot water heater(s) Electric clothes dryer (Loads like ranges, ovens and pool pumps are not connected) As the demand level rises as these appliances are being used the load controller starts a “load shedding” process and starts turning off loads. The loads are programmed with priorities and typically the water heater being the lowest, then the clothes dryer with the a/c units going off last.  As the demand level drops the loads are staged to come back on to maintain the demand level chosen by the end user.  The lower you set it, the more you save.  Load controllers do not need maintenance and systems we have installed over 30 years ago are still in operation.     

For more information on how a load controller works click here.

A Dencor Load Controller installed

A Dencor Load Controller installed