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Calculator to Compute Savings by Replacing HPS Street Lamps with LED Lamps - Generic Model - 2009
Disclaimer: This is a generic calculator - author does not vouch for validity of the data nor the methodology utilized in the model.

*Changeable fields are yellow.

# of streetlights in City 
3000
2000
500
1000
HPS lamps 70W
100W
150W
250W
# of Lamps
HPS power consumption (in Watts)
Mercury content in HPS bulb (mg)
Replacement LED fixture type 20W
30W
60W
90W
Replacement LED fixture unit cost before tax
Installation cost per unit
LED power consumption (in Watts)
% wattage reduction %
%
%
%
LED bulb useful life (in hours)
LED bulb useful life (in yrs)
Dimming Control System costs (all $ before tax)
Dimming control flag
(1= with control; 0 = no)
Segment controller
 		 $
1 set of segment controller + modem for every 200 fixtures
Modem and router $
 
Wireless bridge
1 wireless bridge per circuit, approx 10 fixtures per circuit 		 $
Segment controller installation cost $
i.Lon chip per fixture $  
Monthly wireless service ($/month) $
per unit cost for dimming control costs $
Hours dimmed per day
% dimmed %
First year energy savings (in kWh)
Common Inputs  
Annual Increase
Number of hours in operation per year
NA
  
Price of Electricity ($/kWh) $
%
GHG Intensity of Electricity
(lbs CO2e/kWh)
NA
Price of GHG Emissions ($/ton) $
%
Mercury Emissions Factor (mg/KwH)
NA
Cost to recycle one HPS bulb $
NA
Maximum life assumed for LED
(Life limit years)		 25  
Maximum life assumed for HPS bulb
(Life years)		 5
Annual maintenance cost for all HPS fixtures $
Average annual per unit maintenance cost $  
Labor and truck cost to visit a pole fixture $  
% of HPS maintenance cost reduction
%
% of HPS maintenance cost for LED fixtures
%
Cost of Money/Discount factor
%
Annual Increase in material and labor cost
%
Tax rate (for material purchase)
%
HPS Material Costs per unit (all$ before tax) 70W
100W
150W
250W
Bulb Cost  $
$
$
$
Bulb Life (hours)
Bulb replacement schedule (years)
Ballast Cost $
$
$
$
Ballast Life (Years)
Fixture Cost $
$
$
$
Fixture Life (Years)
Igniter Cost $
$
$
$
Igniter Life (Years)
Photocell Cost
Photocell life (years)