The annual cost savings is calculated by multiplying the annual energy savings by the fuel cost. This represents the monetary benefit of implementing the waste heat recovery system.

\begin{equation}\label{eq:water-heating-flue-annual-cost-savings} C_{annual} = E_{annual} \cdot C_{fuel}\end{equation}

Symbols

\(C_{annual}\)	Annual cost savings \([\unit{ \dollar\per\year}]\)
\(E_{annual}\)	Annual energy savings \([\unit{ \giga\joule\per\year}]\)
\(C_{fuel}\)	Fuel cost \([\unit{ \dollar\per\giga\joule}]\)