Cost saving comparator for low energy bulbs Enter your figures into the black boxes then press Recalculate    
 
  Standard bulb   Energy saving bulb         Saving  
 
Life of bulb             hours     hours   times longer life  
Power of bulb             watts     watts   less watts used  
Cost of bulb                  £'s     £'s   £'s saving(in bulbs) over life of bulb  
Power used(over the life of the low energy bulb) Kw hours   Kw hours   Kw hours saved over life of energy saver bulb
             
Bulb use                   hours per day            
Unit cost of electricity (Kw hour)                £'s            
             
  Cost saving in year one one(taking the more expensive bulb cost into account) £'s (if it's minus that's a loss)  
  CO2 saving in year one   Kg. of CO2  
         
  Pay back (time based on extra cost of bulb minus electricity saving) time(based on the extra cost of low energy bulb minus saving in electricity) Days  
  CO2 saving at point of pay back time   Kg. Of CO2  
         
  Combined cost saving of bulb and electricity over life of low energy bulb (over the life time of the low energy bulb) £'s  
  CO2 saving over the life of the low energy bulb   Kg. of CO2  

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