Abstract: A hydraulic air compressor and generator system may comprise: a hydraulic air compressor comprising a compressed air pipe for conveying the compressed air from the separator chamber; and an electrical power generator positioned in line with the compressed air pipe so that compressed air will directly power the generator. A method for operating an electrical power generator may comprise: positioning the electrical power generator in line with a compressed air pipe of a hydraulic air compressor; and using compressed air output from the HAC to directly power the electrical power generator.