Lighting

This briefing from the Rocky Mountain Institute (RMI) provides guidance on improving home lighting energy efficiency. It advocates for a 'whole-system' approach—combining efficient bulbs like Compact Fluorescent Lamps (CFLs) and LEDs with dedicated fixtures, lighting controls, and daylighting strategies—to reduce electricity costs and improve lighting quality.

• Lighting represents 5–10 percent of total energy use in an average U.S. home, costing between $50 and $150 annually. Standard incandescent bulbs are highly inefficient, as more than 90 percent of their energy consumption is released as heat rather than light.
• A 'whole-system' upgrade is significantly more effective than simply replacing bulbs. In one office analysis, replacing bulbs alone saved 35 percent of energy with a 4.7-year payback; however, combining bulb replacement with upgraded fixtures, occupancy sensors, and photocells increased energy savings to 86 percent and reduced the payback time to 3.2 years.
• Compact Fluorescent Lamps (CFLs) are a primary energy-efficient alternative to incandescents, using about one-quarter of the electricity and lasting 10,000–12,000 hours. While screw-based CFLs are common, dedicated CFL fixtures are recommended to avoid overheating (which can reduce light output by 20 percent) and to optimize optical performance.
• The use of CFLs results in a net reduction of mercury emissions because they reduce the demand for electricity from coal-burning power plants. Using a CFL instead of an incandescent bulb reduces mercury released by these plants by 36 percent, and this reduction increases to 76 percent if the CFL is recycled.
• Halogen torchieres are identified as a significant fire hazard and energy waste due to their 300-watt bulbs operating at approximately 970°F (520°C). They have been banned at two-thirds of U.S. colleges and universities. Replacing them with CFL torchieres, which operate at an average of 104°F (40°C), improves safety and reduces carbon dioxide emissions by an amount equivalent to driving a medium-sized car 743 miles per year.
• Other energy-saving strategies include maximizing daylighting through the use of light-shelves, light pipes (costing under $400), and spectrally selective glazing. Additionally, implementing task lighting to provide lumens only where needed and using controls such as dimmers, timers, and sensors (ultrasonic, infrared, and photosensors) can further reduce energy consumption.

APA

Goorskey, S., Smith, A., & Wang, K. (2004). Lighting. RMI. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB2Lighting.pdf

Chicago

Goorskey, Sarah, Andy Smith, and Katherine Wang. Lighting. RMI, 2004. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB2Lighting.pdf.

Wikipedia

{{cite report |last1=Goorskey |first1=Sarah |last2=Smith |first2=Andy |last3=Wang |first3=Katherine |title=Lighting |publisher=RMI |date=3 December 2004 |url=https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB2Lighting.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{goorskey2004lighting, author = {Goorskey, Sarah and Smith, Andy and Wang, Katherine}, title = {{Lighting}}, institution = {RMI}, year = {2004}, month = dec, url = {https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB2Lighting.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }