Most installation sites are either ongoing construction projects or existing facilities; therefore, electrical power is most often available. However, we recommend keeping a small portable generator handy, like the one shown below. From the power supply, two 100' construction grade extension chords are typically run to the work area. Each main line should be equipped with a threeway splitter and three 25' construction grade extension chords as shown below. Make sure each 25' extension chord is rated to handle more amps than your highest amp power tool. Also, make sure that each main supply line (and splitter) is rated to handle more amps than the combined amperage from all three 25' extension chords.

These items are available at many of your local tool supply shops like Grainger.