Let’s discuss load controllers and how consumers might use one to reduce their electricity bill. First, what exactly is a load controller? Basically, when installed it automatically controls which electrical devices can operate at any given time.
Great, but why is this important? Because having two or more devices consuming a large amount of electricity at the same time can be expensive. And the reason is demand. Some utility rate plans reward the property owner when demand is minimized during peak power periods.
And what exactly is demand? Well demand, measured in kW, is the total amount of electrical load measured at an instant in time. For example, run one 1500-watt hairdryer and it will contribute 1.5 kW to demand. Turn on a second, identical hair dryer at the same time and their total demand will be 3.0 kW. Finish using the first hairdryer before turning on the second one and the demand never goes over 1.5 kW.
Why do I care? Well, if your utility rate plan does not charge for demand, perhaps you don’t. However, the most cost-effective utility plans are those which do bill for demand. The reason is that with a demand charge the consumption charge is much lower.
So, with demand plans, running the two hairdryers for a period of time, but not the same period of time would result in significant savings over running them at the same time.
A load controller will allow the property owner to choose which electrical device is a priority and which devices are a lower priority. For example, the refrigerator and freezer may be priority one, and the load controller will attempt to have them run at all times necessary.
Air conditioners or furnaces might be the second highest priority, but the load controller would attempt to run them when the fridge and freezer are not running. Where there are two AC units or furnaces, the attempt will be made to run each at separate times.
Lights, some outlets and cooking appliances may be the third priority, while the washer/dryer, dishwasher, pool pump and spa might be prevented from operating during peak power periods.
The property owner has the ability to program the load controller as desired, and override these functions, if necessary, when the need arises.
Load controllers can be used with or without solar. The added benefit with solar is that control can be deferred during on-peak periods when sufficient solar electricity is being generated to offset any utility demand concerns.
The cost to acquire and install a load controller is significant and there needs to be an expectation of reasonable return on the investment. An electrical bill where the demand is quite high and variable is a prime candidate to have demand stabilized and reduced with a load controller. This investment should always be compared to switching the utility billing plan to consumption only, without demand charges.
There you go, yet another opportunity to save on your utilities!