In some ways, the power system is the simplest – similar technology can be found in most industrial settings. The most common type of power system is referred to as the diesel-electric system. Diesel-electric rigs use generators to make alternating current electricity, which is then routed through a rectifier to convert the electricity to direct current then on to electric motors powering the various rig systems
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A typical rig has two to four diesel generators that can generate 1,000 horsepower or more each. Like almost everything else on a drill site, these generators are delivered on modular trailers. Power is transmitted to a central control rectifier, which in turn delivers power to electric motors powering the other systems of the rig.
One advantage of diesel electric systems is that the generators can be set up away from the rig, which reduces noise and vibration and reduces the risk of a fire. This contrasts with older mechanical systems that rely on a series of gears, belts, and clutches to transmit power across the rig site and increase the need to be set up immediately next to the rig floor.
Images: “Generators” by Michael Black ; “Tank Close-up” by Michael Black ; “Power Trailers” by Michael Black