Have you stopped at or driven by a convenience store in the middle of the day and noticed the canopy lights over the gas pumps are on? Or have you noticed a streetlight in your area that never shuts off? What about a glaring yard light that irradiates over much more than the owner’s yard? Finally, when is the last time you entered a room and found the lights were left on after the last person left? These are all examples of improper or needless use of electricity through illumination.
Through the 2020 Residential Energy Consumption Survey, the U.S. Energy Information Administration found that electricity consumption for lighting accounted for about 6% of the electrical use in U.S. homes. That equates to 81 billion kilowatt-hours (kWh) of electricity. In similar surveys for commercial buildings and industrial facilities, lighting accounted for about 17% (208 billion kWh) and 6% (53 billion kWh) of total electricity use in those areas respectively. Unfortunately, it is estimated that about half of all energy used for lighting is unnecessarily lost.
Here are the leading causes of wasted lighting energy:
- Over-illumination – using too much light or leaving lights on unnecessarily.
- Inefficient fixtures – light is lost within the fixture before it can provide illumination of the desired area.
- Inefficient light source – bulbs like incandescent bulbs waste energy by creating much more heat than light.
- Poor fixture design – Some are not properly shielded and/or aimed sending light where it is not needed or desired. Poor design usually leads to glare. The picture to the right illustrates this problem. The fixture on the left either lost its shielding or never had any causing light to go directly into the observer’s eyes. The fixture on the right is properly shielded. Most of the light produced strikes the area being illuminated before reflecting into our eyes.
- Uncontrolled lighting – lack of lighting controls, occupancy sensors, or dimming systems allow lights to run unnecessarily.
- Not utilizing natural light – not taking advantage of natural daylight when and where it is available can lead to increased reliance on artificial lighting.
Now that you know the primary causes, here are the solutions:
- Energy-efficient lighting – Switching to energy-efficient LED lighting and using smart lighting controls.
- Proper fixture design – Ensuring light fixtures are shielded and aimed correctly by directing light only where it’s needed, reducing waste and glare.
- Natural light utilization – Maximizing natural daylight through window placement during building design to reduce the dependence on artificial lighting.
- Lighting controls – Installing and integrating occupancy and daylight sensors, smart switches, smart building systems and task lighting to optimize energy use.
Your local electric utility wants to help you gain the most beneficial light from the energy you purchase. They even offer EnergyWiseSM lighting incentives to help you make the most efficient choice. To find additional information, contact your local utility.