ClueLuma

Total annual net savings calculator

Combine energy, demand, HVAC and maintenance effects consistently.

Snet=Senergy+Sdemand+Ecooling×re−Cheat−ΔClamp+SlaborS_{\text{net}} = S_{\text{energy}} + S_{\text{demand}} + E_{\text{cooling}} \times r_{e} - C_{\text{heat}} - {\Delta C_{\text{lamp}}} + S_{\text{labor}}

Calculator

Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.

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Worked example

Given

  • EcoolingE_{\text{cooling}} = 3,500 kWh/yr
  • SenergyS_{\text{energy}} = 5,200 $/yr
  • SdemandS_{\text{demand}} = 2,080 $/yr
  • ΔClamp{\Delta C_{\text{lamp}}} = 300 $/yr
  • SlaborS_{\text{labor}} = 600 $/yr
  • CheatC_{\text{heat}} = 1,150 $/yr
  • rer_{e} = 0.12 $/kWh
Snet=5200+2080+3500×0.12−1150−300+600=6,850S_{\text{net}} = 5200 + 2080 + 3500 \times 0.12 - 1150 - 300 + 600 = 6{,}850

Symbols and units

SymbolMeaningUnit
SnetS_{\text{net}}annual net savings$/yr
EcoolingE_{\text{cooling}}cooling energy savingskWh/yr
SenergyS_{\text{energy}}energy-charge savings$/yr
SdemandS_{\text{demand}}demand-charge savings$/yr
ΔClamp{\Delta C_{\text{lamp}}}added lamp purchase cost$/yr
SlaborS_{\text{labor}}labor savings$/yr
CheatC_{\text{heat}}added heating cost$/yr
rer_{e}electric rate$/kWh

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Results are estimates for study and screening. Check the inputs, units and assumptions before you use them for design, billing or contract decisions.