The power meter method uses a direct power reading from an installed or portable power meter. The reading is multiplied by the quantity multiplier (units) and the annual operating hours to obtain total annual energy use.

\begin{equation}\label{eq:electricity-reduction-power-meter} E = P_{meter} \cdot n \cdot t_{op}\end{equation}

Symbols

\(E\)	Annual energy use \([\unit{ \kilo\watt\hour\per\year}]\)
\(P_{meter}\)	Direct power reading from the power meter \([\unit{ \kilo\watt}]\)
\(n\)	Quantity multiplier (number of identical loads) \([\unit{ \unitless}]\)
\(t_{op}\)	Annual operating hours \([\unit{ \hour\per\year}]\)