Mobile power generator supplying film lighting and on-set equipment. Standard generators deliver 25–150 kW, consuming approximately 25 liters of diesel per hour at 100 kW.
Technical Details
Standard film generators are based on synchronous generators with brushless excitation systems and AVR (Automatic Voltage Regulation) voltage regulators. A 100 kW generator consumes approximately 25 liters of diesel per hour at full load and weighs between 1,500-2,000 kg. The sound power level is 60-75 dB(A) at a distance of 7m. Modern inverter generators produce clean power with less than 3% harmonic distortion (THD), essential for sensitive digital cameras and LED lighting. Variants include whisper generators (under 55 dB), high-frequency units (400 Hz for flicker-free HMI lighting), and hybrid systems with battery buffering.
History & Development
The first film generators emerged in the 1920s for studio lighting, initially as stationary steam engine units. In 1935, the company Mole-Richardson introduced mobile diesel generators. The breakthrough came in 1960 with compact 25 kW units on trailers. In the 1980s, low-noise whisper generators became established for sound recording. Since 2010, electronically controlled inverter systems with precise frequency and voltage stabilization have dominated digital workflows.
Practical Use in Film
Generators power complete lighting setups: a 60 kW unit operates 6-8 HMI lights of 6 kW each or 40-50 LED panels. For "Mad Max: Fury Road," specially modified 150 kW trailer generators were used to provide lighting during driving sequences. Whisper generators are placed at least 50m from the sound set, connected by distribution cables up to 100m long. Load banks test the units under full load before shooting begins. During night shoots, generators often run continuously for 12-16 hours.
Comparison & Alternatives
Generators differ from uninterruptible power supplies (UPS) by providing continuous power generation rather than buffering. Mobile battery systems like Cinegy V-Mount arrays replace small generators for LED lighting up to 5 kW for 2-4 hours. Hydrogen fuel cell generators offer emission-free operation but cost 3-4 times more. Mains connections (shore power) remain the first choice when infrastructure is available. Hybrid systems combine 20-50 kW generators with lithium batteries for noise-sensitive scenes.