A Load control switch is a remotely controlled

Remote control

A remote control is a component of an electronics device, most commonly a television set, used for operating the television device wirelessly from a short line-of-sight distance.The remote control is usually contracted to remote...

 relay

Relay

A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism mechanically, but other operating principles are also used. Relays are used where it is necessary to control a circuit by a low-power signal , or where several circuits must be controlled...

 that is placed on home appliance

Home appliance

Home appliances are electrical/mechanical machines which accomplish some household functions, such as cooking or cleaning. Home appliances can be classified into:*Major appliances, or White goods*Small appliances, or Brown goods...

s which consume large amounts of electricity

Electricity

Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

, such as air conditioner units and electric water heaters

Water heating

Water heating is a thermodynamic process using an energy source to heat water above its initial temperature. Typical domestic uses of hot water are for cooking, cleaning, bathing, and space heating...

.

Most load control switches consist of a communication module and the relay switch and can be used as part of a demand response

Demand response

In electricity grids, demand response is similar to dynamic demand mechanisms to manage customer consumption of electricity in response to supply conditions, for example, having electricity customers reduce their consumption at critical times or in response to market prices...

 energy efficiency system such as a smart grid. Such a switch operates similarly to a pager

Pager

A pager is a simple personal telecommunications device for short messages. A one-way numeric pager can only receive a message consisting of a few digits, typically a phone number that the user is then requested to call...

, receiving signals from the power company or electrical frequency shift to turn off or reduce power to the appliance during times of peak electrical demand. Usually, the device has a timer

Timer

A timer is a specialized type of clock. A timer can be used to control the sequence of an event or process. Whereas a stopwatch counts upwards from zero for measuring elapsed time, a timer counts down from a specified time interval, like an hourglass.Timers can be mechanical, electromechanical,...

 that will automatically reset the switch back on after a preset time. Some operation intolerant appliances, such as dryers, use switches that can reduce or shut off power to their heating coils yet still tumble until signaled to resume full power .

Most load control switches have only one-way communication

Simplex communication

Simplex communication refers to communication that occurs in one direction only. Two definitions have arisen over time: a common definition, which is used in ANSI standard and elsewhere, and an ITU-T definition...

, receiving signals from the power company. Some are now two-way

Duplex (telecommunications)

A duplex communication system is a system composed of two connected parties or devices that can communicate with one another in both directions. The term multiplexing is used when describing communication between more than two parties or devices....

, which helps the power company locate faulty load control switches. Others are stand alone at the appliance and operate independently by monitoring electrical load without contacting anyone. Many electric cooperatives

Utility cooperative

A utility cooperative is a type of cooperative that is tasked with the delivery of a public utility such as electricity, water or telecommunications to its members...

 offer free installation of load control switches to their members, sometimes with incentive

Incentive

In economics and sociology, an incentive is any factor that enables or motivates a particular course of action, or counts as a reason for preferring one choice to the alternatives. It is an expectation that encourages people to behave in a certain way...

s.

Load control switches can be a powerful tool to prevent brown-outs and black-outs

Power outage

A power outage is a short- or long-term loss of the electric power to an area.There are many causes of power failures in an electricity network...

 when electricity storage

Grid energy storage

Grid energy storage refers to the methods used to store electricity on a large scale within an electrical power grid. Electrical energy is stored during times when production exceeds consumption and the stores are used at times when consumption exceeds production...

, transmission, or generation resources are insufficient. It allows the electric companies to respond to emergencies without shutting off all power to customers. They also reduce costs for electric companies by reducing the amount of expensive electricity they need to buy from other companies during peak demand.