LIGHTING LEADS 21st CENTURY REDUCTION IN USE OF ELECTRICITY IN RESIDENTIAL AND COMMERCIAL BUILDINGS

LIGHTING LEADS 21st CENTURY REDUCTION IN USE OF ELECTRICITY IN RESIDENTIAL AND COMMERCIAL BUILDINGS

Clark R. Silcox, General Counsel, NEMA

Over the first 18 years of the 21st century, lighting products contributed more than any other product to reducing the demand for electricity in the United States, according to data published by U.S. Energy Information Administration (EIA) in their Annual Energy Outlook (AEO) from 2004 – 2019.  Overall annual electricity use from lighting — in both the residential and commercial sectors — fell 57% from 2001 – 2018 from an estimated 1.82 quads in 2001 to an estimated 0.79 quads in 2018.  A quad represents a quadrillion BTUs of energy and is equivalent to 293 billion kilowatt hours of electricity. Lighting led all other product categories both in terms of the absolute reduction in estimated electricity use and in percentage reduction.  No other category of appliances or equipment came close the reduction in electricity use that lighting contributed.

Notwithstanding the dramatic decline in electricity use from lighting in the 21st century, overall electricity demand in the residential and commercial sectors in the United States rose an estimated 18% over the 18-year period or approximately 1% per year, according to the same AEO reports.  The EIA Annual Energy Outlook does not include estimates for industrial-sector electricity use.  In a separate report, EIA estimates that electricity use in the industrial sector has declined during the same time.

The lighting products’ contribution to mitigating the increased demand for electricity was significant.  Electricity use in the residential and commercial sectors over the period grew by an estimated 1.48 quads from 8.19 quads in 2001 to 9.67 quads in 2018.  If the use of electricity by lighting products had remained flat over the same period, overall electricity use in residences and commercial buildings would have grown by 2.51 quads instead of 1.48 quads.  The 1.03 quad reduction in annual electricity use from lighting by 2018 is equivalent to 300 billion kilowatt hours of electricity, about 7% of the 4.18 trillion kilowatt hour utility scale electricity generation in the United States during 2018.

The trajectory of lighting and overall electricity use from 2001-2018 is displayed in the two graphs below.  Electricity use from lighting is declining; overall electricity use is rising modestly or flat during this period.

The significant decline in electricity use from lighting began in 2009 after a gradual decline from 2001-2008.  The decline beginning in 2009 coincides with the growing penetration of compact fluorescent light bulbs (CFL) in general service lamp sockets helped by technical improvements in the CFL made by manufacturers and marketing efforts associated with the Energy Star program.  The decline in electricity use from lighting continued steadily each year after 2009, coinciding with higher federal energy conservation Standards for fluorescent tubes, standard incandescent light bulbs, incandescent reflector lamps, decorative lamps, and components such as fluorescent and metal halide ballasts. The more widespread use of lighting controls also contributed to this decline. The most significant decline, however, occurred in 2015-2018, according to the EIA estimates.  This decline had little to do with federal energy regulation of lighting.  LED lighting started achieving more substantial market penetration in 2015 and by 2017 shipments of LED light bulbs surpassed the incandescent light bulb in key lamp categories — standard general service light bulbs, reflector light bulbs, and more recently decorative light bulbs.  In the commercial sector, incandescent and fluorescent lighting is being rapidly replaced by integrated LED fixtures, LED bulbs, and tubular LEDs.  Domestic fluorescent lighting shipments have declined approximately 50% since 2015; compact fluorescent lamp shipments have declined by nearly 85% since 2015 while standard incandescent light bulb shipments have declined by 35% in the same period (standard incandescent bulb shipments falling 83% since its peak in 2003).  These developments are reflected in the first graph above.

The AEO reports, summarized in Table I, below, reveal a larger decline in absolute electricity use from lighting in commercial applications compared to residential applications (-0.62 quads vs -0.41 quads), but in percentage terms the reduction in electricity use was virtually identical.

Table I. Delivered Electricity for Lighting Use in Quads20012018∆2001-2018 quads∆ 2001-2018 Percent
Lighting Residential0.720.31-0.41-57%
Lighting Commercial1.10.48-0.62-56%
Lighting Total1.820.79-1.03-57%
Source:  U.S. EIA, AEO 2004-2019.

By comparison, reductions in annual electricity use over the 18-year period of the 21st century were contributed by residential refrigerators, freezers, cooking appliances, and clothes dryers, commercial water heating and commercial space heating totaling an estimated 0.41 quads annually in 2018 compared to 2001, according to the AEO reports.  This additional aggregate reduction in electricity use from these appliances and equipment represent 40% of the reduced electricity use from lighting alone, demonstrating just how much lighting has contributed to electricity savings in the 21st century.  Some electricity-using products modeled by EIA are seasonally-sensitive, such as space cooling and space heating, and electricity use associated with those products rises or falls depending on temperatures being warmer or colder than previous seasons.  The EIA data on delivered electricity consumption by product category is summarized in Table II below.

Table II.  Delivered Electricity Consumption by Use
Commercial∆ 2001-2018 Percent∆2001-2018 quads
Space heating-12%-0.02
Space Cooling36%0.15
Water heating-82%-0.11
Ventilation220%0.32
Cooking183%0.05
Lighting-56%-0.62
Refrigeration225%0.45
Office Equipment (PC)141%0.20
Office Equipment (non-PC)28%0.09
Other Uses5%0.08
Total14%0.59
Residential∆ 2001-2018 Percent∆2001-2018 quads
Space heating86%0.33
Space Cooling16%0.10
Water heating56%0.21
Refrigeration-31%-0.13
Cooking-46%-0.05
Clothes Dryers-11%-0.02
Freezers-51%-0.07
Lighting-57%-0.41
Clothes Washers19%0.01
Dishwashers27%0.01
Televisions/set top boxes77%0.09
Personal computers50%0.03
Furnace Fans/Boiler pumps23%0.02
Other Uses99%0.78
Total22%0.89
Source:  U.S. EIA, AEO 2004-2019.

The change in lighting products’ status as a user of electricity is reflected in the fact that lighting was the largest category user in 2001 and ranks a middling 5th in 2018.  Where lighting represented an estimated 22% of overall electricity use in the residential and commercial sectors in 2001, according to the AEO reports, it represented only an estimated 8% of overall electricity use in those sectors in 2018.

The EIA Annual Energy Outlook for 2019 forecasts additional electricity savings from lighting in the next four years as would be expected from the remaining transition to LED lighting that has not already taken place.  It is clear from the EIA data, however, that the bulk of the electricity savings from lighting has already occurred as the projected future annual electricity savings of .15 quads foreseen by EIA models is only 14% of what occurred over the past 18 years.

Ironically, EIA forecast in its 2004 Annual Energy Outlook envisioned rising electricity use from lighting.  EIA projected that electricity use in the residential and commercial sectors would rise from 1.82 quads in 2001 to 2.37 quads in 2020, a rise of 30% over 20 years.  At that time, no one foresaw the extent to which conventional incandescent and fluorescent lighting products would become more energy efficient, and no one saw the rapid research, development, commercialization and market penetration of LED lighting either.  Instead, the United States witnessed lighting’s decline in electricity use from an estimated 1.82 quads to 0.79 quads, a decline of 57% over 18 years. The graph below compares EIA AEO 2004 forecast for electricity use from lighting from 2001 – 2020 with actual estimated electricity use from lighting over the same period (including the 2020 forecast in the EIA AEO 2019 report).

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