Emissions Reduction Toolkit

Install Motion Sensors For Lighting

What Is It?

Occupancy or motion sensors — sometimes called vacancy or personnel sensors — are one of the most common energy efficient lighting strategies. They detect the movement of room occupants, turning off lights in unoccupied areas and turning them back on when occupants return. The most effective areas for sensors are areas that are not frequently used, areas with irregular use patterns, or areas where occupancy may be erratic and where lights are often and inadvertently left on, such as meeting or conference rooms, individual offices, copier rooms, bathrooms, and storage areas.

Occupancy sensors are comprised of a motion detector, which uses ultrasonic, passive infrared or dual technology; an electronic control unit; a controllable switch (relay); and a power supply (Graybar). There are various locations where a sensor can be mounted — such as wall (where a regular switch might go), ceiling, or upper corner — and one should consider the type of space (small room, narrow hallway, etc.) before mounting. Occupancy sensors only provide optimal results if they are calibrated, wired, and placed correctly. Users should carefully commission their control system to fit the particular space and communicate clearly with installers about their particular spaces, then monitor energy savings and success of technology for a span of time after installation. It is also essential to evaluate need before choosing light and sensor types. This can be done beforehand, using data logging techniques, some of which are explored on page 26 of ENERGY STAR’s Chapter on Lighting from their Building Upgrades Manual. You can find details on how to calculate energy savings here and how to find the return on investment (ROI) here.

Suggested motion sensor types based on location

1. From Hubbell: Energy Savings with Occupancy Sensors
2. From Pacific Gas and Electric: Occupancy Controls for Lighting
3. From US DOE: Energy Efficient Lighting

Benefits

Motion sensors are inexpensive and effective devices that can quickly and easily be installed on a wall or ceiling. Most pay for themselves in two to three years without rebates. Where utility rebates are available, the payback can be less than one year. Savings will vary depending on the area size, type of lighting, and occupancy pattern. Potential savings from motion sensor controls vary greatly, but study on the energy savings potential of lighting controls in commercial buildings found that daylighting control strategies can save an average of 30% of energy used (ACEEE) can save between 13-90% of lighting energy costs (Graybar).

Drawbacks

Though occupancy sensors are the most commonly used lighting control mechanism, they must be carefully evaluated before and during the beginning of use. Some sensor systems can return no or negative energy saving results due to failure to commission them properly or monitor the reality of time during which the lights are on. If sensors are not calibrated properly or the right type of sensors are not used, they can be falsely triggered or stay on too long, wasting energy, or can go off too early without sensing movement, sending occupants into darkness.

Regulatory Impacts and Requirements

ASHRAE 90.1 (2010) gives standards for minimum efficiency in nonresidential (including high-rise residential and hotels) and commercial buildings. It requires that new buildings use occupancy sensors in all rooms of a certain type (see pg. 16 of NEMA’s document).

See also: National Electrical Manufacturers Association’s Guidance on 2005 Energy Policy Act (as modified in 2015).

Financing Options, Incentives, and Rebates

• Federal Energy Management Program:Procuring Energy-Efficient Products
• NEMA’s Guidance on Energy Policy Act Commercial Building’s Tax Deduction Letters
• S. Department of Energy:Outline of Energy Conservation and Efficiency Incentives
• MassSave:Lighting and Lighting Controls Upgrades – Large Retrofits
  • Sustainable Office Design incentives for efficient lighting in office buildings
• National Grid Rebates: save up to 45% on energy-efficient lighting

• Lighting for existing buildings: Systems and Sensors; Performance Lighting
• Lighting for new buildings or major renovations: Systems and Sensors; Performance Lighting

• Puget Sound Energy: commercial lighting incentives
• Concord Municipal High Efficiency Lighting Program
• Reading Municipal Light Department
• Mass Save, for residential lighting: Efficient lighting discounts for electric customers with National Grid, Cape Light Compact, Eversource, or Unitil
• National search engines and programs

• US Department of Energy GreenBuy Award Program – 2017
• Property Assessed Clean Energy program (PACENow)
• Database of State Incentives for Renewables & Efficiency (DSIRE)
• US DOE database for Tax Credits, Rebates, and Savings on energy efficient technologies

NEWS

• “Higher Occupancy Sensor Resolution Promises Greater Savings,” Lighting Controls Association, July 22, 2015
• “New York Plan to Save Energy May Mean a Dimmer Skyline,”The New York Times, April 29, 2015
• “Copenhagen Lighting the Way to Greener, More Efficient Cities,” The New York Times, Dec. 8, 2014

RESOURCES

• Pacific Gas and Electric: Occupancy Controls for Lighting
• ENERGY STAR: Chapter on Lighting from their Buildings Upgrades Manual
• State of Michigan: Energy-efficient Lighting
• Lighting Controls Association
  • video on occupancy sensor basics
• S. DOE: “How to Select Lighting Controls For Offices and Public Buildings”
  • “LED Troffer Retrofit Lighting and Controls Best Practices”
• Facilities Net: “Advanced Lighting Controls Offer Better Control, More Energy Savings”
• DesignLight Consortium (DLC), a non-profit accelerating energy-efficient lighting solutions
• See also: Install Energy-efficient Lighting in this toolkit

A SAMPLE OF PROVIDERS

• Hubbell Vacancy-Occupancy Sensors
• Lighting Science
• Boston Light Source
• Graybar
• DLC: Qualified Products List

PROJECT EXAMPLES

• Boston University retrofitted garages with efficient fluorescents and an occupancy control system.
• The Rockport Company, a division of Reebok, installed occupancy controls and new T-5 fluorescent lights for annual savings of $136,098 and 1,512,206 kWh.