The LED Upgrade Analysis compares your existing lighting against new LED options by fixture type. Each type can have its own hours per day, quantities, wattage, and optional maintenance + lifespan inputs. The tool outputs monthly energy/cost, annual savings, simple payback (if you add install cost), and an over-lifespan cost comparison using the best (longer) lifespan in hours entered for that type.

1. Enter your power cost ($/kWh) and (optional) days per year and installation cost.
    
2. For each fixture type, fill in hours/day, existing and new wattage and quantities.
    
3. (Optional per type) Add maintenance $/year, lifespan (hours) for existing and new, and (optional) existing fixture cost.
    
4. Read monthly costs and savings per type, plus the totals and simple payback at the bottom.
    
5. The lifespan block compares total cost over the best lifespan entered, using that type’s hours/day and your days/year.
    

Monthly energy (kWh) per type

• Existing: kWhm,cur=Wex×Qex×hpd×301000\text{kWh}_{m,cur} = \dfrac{W_{ex}\times Q_{ex}\times hpd \times 30}{1000}kWhm,cur​=1000Wex​×Qex​×hpd×30​
   
• New: kWhm,new=Wnew×Qnew×hpd×301000\text{kWh}_{m,new} = \dfrac{W_{new}\times Q_{new}\times hpd \times 30}{1000}kWhm,new​=1000Wnew​×Qnew​×hpd×30​
   

Monthly cost ($) & savings

• Cost (current): Cm,cur=kWhm,cur×RateC_{m,cur} = \text{kWh}_{m,cur} \times \text{Rate}Cm,cur​=kWhm,cur​×Rate
   
• Cost (new): Cm,new=kWhm,new×RateC_{m,new} = \text{kWh}_{m,new} \times \text{Rate}Cm,new​=kWhm,new​×Rate
   
• Savings: Sm=Cm,cur−Cm,newS_{m} = C_{m,cur} - C_{m,new}Sm​=Cm,cur​−Cm,new​
   

Totals

• Monthly totals: sum across all types
   
• Annual savings: Sy=12×Sm,totS_{y} = 12 \times S_{m,tot}Sy​=12×Sm,tot​
   

Simple payback (years)

• If install cost provided: Payback=Install CostSy\text{Payback} = \dfrac{\text{Install Cost}}{S_{y}}Payback=Sy​Install Cost​
   

Lifespan comparison (per type, using best hours)

• Best hours: Hbest=max⁡(Hex,Hnew)H_{best} = \max(H_{ex}, H_{new})Hbest​=max(Hex​,Hnew​)
   
• Years at this type’s hours/day: Y=Hbesthpd×Days/YearY = \dfrac{H_{best}}{hpd \times \text{Days/Year}}Y=hpd×Days/YearHbest​​
   
• Energy cost over lifespan:
   
  • Existing: Eex=Wex×Qex×Hbest1000×RateE_{ex} = \dfrac{W_{ex}\times Q_{ex}\times H_{best}}{1000}\times \text{Rate}Eex​=1000Wex​×Qex​×Hbest​​×Rate
     
  • New: Enew=Wnew×Qnew×Hbest1000×RateE_{new} = \dfrac{W_{new}\times Q_{new}\times H_{best}}{1000}\times \text{Rate}Enew​=1000Wnew​×Qnew​×Hbest​​×Rate
     
• Maintenance over lifespan:
   
  • Existing: Mex=Maintex×YM_{ex} = \text{Maint}_{ex} \times YMex​=Maintex​×Y
     
  • New: Mnew=Maintnew×YM_{new} = \text{Maint}_{new} \times YMnew​=Maintnew​×Y
     
• Capital (optional, existing only if provided): Cex=FixtureCostex×QexC_{ex} = \text{FixtureCost}_{ex} \times Q_{ex}Cex​=FixtureCostex​×Qex​
   
• Total over lifespan:
   
  • Existing: Tex=Eex+Mex+CexT_{ex} = E_{ex} + M_{ex} + C_{ex}Tex​=Eex​+Mex​+Cex​
     
  • New: Tnew=Enew+MnewT_{new} = E_{new} + M_{new}Tnew​=Enew​+Mnew​
     
• Lifespan savings: Slife=Tex−TnewS_{life} = T_{ex} - T_{new}Slife​=Tex​−Tnew​
   

Assumptions

• Month = 30 days (for monthly energy).
   
• All wattages are input power.
   
• If any inputs are blank/invalid, that term is treated as zero.