How does LED Dusk to Dawn Lighting Work?


Dusk-to-dawn lighting is increasingly common and affordable, but many people still don’t know what it is, and even fewer know how it really works.

It’s time to roll up our sleeves and break down how dusk-to-dawn lighting works and why it’s the best way to extend the value of your outdoor lighting investment.

What is Dusk-to-Dawn Lighting?

Dusk-to-dawn functionality means that a lamp will only switch on and produce light when it is dark outside. During daylight hours (between dawn and dusk), they stay off no matter what. A small sensor known as a photocell monitors ambient conditions to identify when light is necessary.

Dusk-to-dawn lights can also be paired with a motion sensor to produce light only during dark hours when motion is present.

types of dusk to dawn lights

There are many situations where dusk-to-dawn lighting is used, here are just a few:


Having a motion-sensitive dusk-to-dawn light installed around your garage is useful in a number of ways. First, it allows for easy and safe access to the garage when you need it after dark. Secondly, it deters would-be intruders, making your whole home safer.


Keeping the streets around commercial areas illuminated at night encourages late night shoppers and evening restaurant-goers — supporting the local economy at all hours, while residential areas benefit from increased security. All this happens automatically thanks to dusk-to-dawn lighting.

Parking Lots

At night, a shadowy parking lot is an appealing prospect for potential car thieves. Dusk-to-dawn lighting can help protect vehicles and their owners, especially if the parking lot serves an office that could be open around the clock.

Large Commercial Areas

Off-street commercial areas such as docks and warehouses often house high-value items that need protecting. This can be done very effectively by high lumen dusk-to-dawn lighting, enabling security cameras to capture the finest detail while saving on costs for the business owner.

What is a Dusk-to-Dawn Photocell and how do they work?

“Photocell” is short for photoelectric cell — a clever little element used in electrical circuits. Photocells can detect how much light they are being exposed to, then change the amount of electricity the circuit creates.

Photocells are used in dusk-to-dawn lamps to monitor levels of natural light. Once the level drops below a certain figure, the photocell knows to reduce the resistance of the circuit. This allows more current to flow around it, increasing the amount of electricity the circuit generates. When a dusk-to-dawn light turns on, it’s because the photocell has triggered it to.

Then, once the ambient light rises back to a certain level — when the sun comes up in the morning, for example — the photocell knows to decrease the resistance of the circuit. This drops the current down and shuts the light off.

The process is managed by a specific combination of resistors and semiconductors. Together, they ensure that the circuit powers the bulb when there’s little or no natural light around, and that it shuts off once natural light returns.

photocell dusk to dawn resistance graph

The precise level of light that a photocell is sensitive to can be changed depending on what it is being used for. For example, a garage dusk-to-dawn light might only operate once the sun has gone down completely. Street lights in commercial areas might come on just before the sun sets.

Because photoresistors rely on ambient light levels, they are not impacted by daylight saving time and automatically follow seasonal changes.

Does it really save electricity?

Can dusk-to-dawn lighting increase security, encourage the use of public spaces and save on costs too?

If we compare a typical incandescent light bulb with an LED dusk-to-dawn lamp, the cost savings are obvious.

Let’s assume that both are on for an average of 12 hours per day, a 40W halogen bulb will use 480kWh whereas a 6W LED dusk-to-dawn will use only 72kWh. If the average price of electricity is around $0.13/kWh, the total cost for each bulb is:

  • 40W halogen = $62.40/day
  • 6W LED dusk-to-dawn = $9.36/day

That’s a total saving per day of $53.04 when using LED dusk-to-dawn lights.

Dusk-to-dawn lights that are also motion sensitive will be on for fewer hours each day, resulting in even greater savings.

Add to this the fact that the average LED bulb lasts 25 x longer than a halogen bulb, and it’s clear that dusk-to-dawn lighting is more efficient in almost every possible way.

Why is Dusk-to-Dawn Your Best Bet for Outdoor Lighting?

Dusk-to-dawn lighting helps maximize energy savings and return on investment for outdoor lighting. When paired with LED lights, dusk-to-dawn settings create an ultra-efficient system that delivers maximum light when it’s needed while drawing minimal power and eliminating waste.

In the past, many outdoor lighting systems relied on timers. Dusk-to-dawn lights represent a major improvement because they deliver light precisely when it is needed.

As the days stretch longer in the spring and summer, and shorten in the fall and winter, a dusk-to-dawn light will naturally pick up on the changes in sunrise and sunset. The result is an almost zero maintenance outdoor lighting solution, saving you time and money while guaranteeing security and safety too.

Whatever your need for outdoor lighting, dusk-to-dawn LEDs are likely to be one of the best, if not the best, option for you.

Browse the Hyperikon range of residential security lights, photocell barn lights and wall lights to start saving money today.

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