Initial Rated Light Output of Various Lamps

The following list gives an idea of how different types of lamps and lamp wattages yield different amounts of light. The amount of light cast by a lamp is measured in units known as "lumens". Wattage tells you how much energy (electricity) is used to light a given lamp, and this is directly translateable into dollars spent. A single typical streetlight costs taxpayers US$150 per year to light, with some costing up to $400/year or more in electricity costs. A typical suburb in the U.S.A. has 3000-4000 streetlights, costing the taxpayers of that town more than half a million dollars a year in electricity costs alone. Using a full-cutoff fixture means that light that would otherwise be glare (and not useful light), in a dropdish fixture, can be used via reflectors entirely for the region intended to be lit, and consequently that the amount of light output (and therefore the wattage and cost per lamp) can be considerably lowered.

In the list below, the number of lumens is the initial rated lumen output (for a new lamp). Information compiled from large lamp catalogues from Sylvania (Pl-150), General Electric (9200), and Phillips (SG-100). [Information provided courtesy of Peter Talmage, Kennebunkport, ME.]

LAMP TYPE                            MANUFACTURER        WATTS     LUMENS
Incandescent frosted                 Sylvania              25        235
Incandescent frosted                 Sylvania              40        375
Incandescent frosted                 Sylvania              60        890
Incandescent frosted                 Sylvania             100       1690
Incandescent frosted                 Sylvania             150       2850

Incandescent flood or spot           G.E.                  75        765
Incandescent flood or spot           G.E.                 120       1500
Incandescent flood or spot           G.E.                 150       2000

Quartz-halogen frosted               Sylvania              42        665
Quartz-halogen frosted               Sylvania              52        885
Quartz-halogen frosted               Sylvania              72       1300
Quartz-halogen frosted               Sylvania             300       6000
Quartz-halogen frosted               Sylvania             500      10500
Quartz-halogen frosted               Sylvania            1000      21000

Quartz-halogen mini-flood or spot*   G.E.                  20        260
Quartz-halogen mini-flood or spot*   G.E.                  42        630
Quartz-halogen mini-flood or spot*   G.E.                  50        895
Quartz-halogen mini-flood or spot*   G.E.                  75       1300

Fluorescent                          Phillips               7        400
Fluorescent                          Phillips               9        600
Fluorescent                          Phillips              13        900
Fluorescent                          Phillips              22       1200
Fluorescent                          Phillips              28       1600
Fluorescent (cool white)             G.E.                  40       3150

Low-pressure sodium (LPS)            Phillips              18       1800
Low-pressure sodium (LPS)            Phillips              35       4800
Low-pressure sodium (LPS)            Phillips              55       8000
Low-pressure sodium (LPS)            Phillips              90      13500
Low-pressure sodium (LPS)            Phillips             135      22500
Low-pressure sodium (LPS)            Phillips             180      33000

High-pressure sodium (HPS) diffuse   G.E.                  35       2250
High-pressure sodium (HPS) diffuse   G.E.                  50       4000
High-pressure sodium (HPS) diffuse   G.E.                  70       6400
High-pressure sodium (HPS) diffuse   G.E.                 100       9500
High-pressure sodium (HPS) diffuse   G.E.                 150      16000
High-pressure sodium (HPS) diffuse   G.E.                 250      27500
High-pressure sodium (HPS) diffuse   G.E.                 400      50000

Mercury-vapor (white deluxe)         Sylvania             100       4500
Mercury-vapor (white deluxe)         Sylvania             175       8500**
Mercury-vapor (white deluxe)         Sylvania             250      11100
Mercury-vapor (white deluxe)         Sylvania             400      20100

Metal-halide (coated)                G.E.                  32       2500
Metal-halide (coated)                Venture               50       3400
Metal-halide (coated)                G.E.                 100       9000
Metal-halide (coated)                G.E.                 175      15750
Metal-halide (coated)                G.E.                 250      20500
Metal-halide (coated)                G.E.                 400      36000

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* 12-volt MR-16 type
** possible typo

Also available is information from the International Dark-Sky Association.