This 29% boost in system efficacy is due mainly to the replacement of incandescent bulbs with compact fluorescent lamps (CFLs) in residential applications, and to the replacement of T12 fluorescent lamps with T8 and T5 fluorescent lamps in commercial and industrial sectors.
The efficacies of each of the sectors shows that residential is the sector most in need of improvement with an average efficacy of 19 lm/W, significantly below the other three sectors, which have average efficacies at or above 70 lm/W. The improvement in industrial and outdoor sector efficacies is attributed to a migration from mercury-vapor lamps to metal-halide lamps.
At the same time, new construction has led to an overall 14% increase in the total number of lamps installed in the US. The total number of lamps installed increased from 7 billion in 2001 to 8 billion in 2010, largely in the residential sector.
Of the 8 billion installed lamps, 67 million are based on LEDs (0.8% of total units). By market, the greatest number of LED lamps are found in outdoor applications, with 38.0 million lamps, 19.2 million lamps in commercial applications, 9.2 million in residential and 0.59 million in industrial applications.
Although the residential sector (175 TWh) contained far more installed lamps, most of them incandescent, these lamps experience less daily use, on average, than commercial-sector lamps.
It's worth noting that LEDs barely register on the chart of total electricity consumption in Fig. 2.
To download a PDF of the full report, go to www.ssl.energy.gov/tech_reports.html.
