When the electricity cost basis is selected (utility_type = 1), the compressor's specific power (kW per cfm of air delivery) is used to convert the annual air volume into electrical energy. Dividing the specific power by 60 converts from kW/(ft³/min) to kW·hr/scf so that multiplying by the annual volume (in scf) yields kilowatt-hours.

\begin{equation}\label{eq:leak-survey-electricity} E_{annual} = \frac{k_{sp}}{60} \cdot V_{annual} \end{equation}

Symbols

\(E_{annual}\)	Annual electrical energy consumed to replace leaked air \([\unit{ \kilo\watt\hour}]\)
\(k_{sp}\)	Compressor specific power \([\unit{ \kilo\watt\minute\per\cubicFoot}]\)
\(60\)	Minutes per hour conversion \([\unit{ \minute\per\hour}]\)
\(V_{annual}\)	Annual compressed air volume for this survey entry \([\unit{ \scf}]\)