NOVELTY - Recovery motor (24) recovers and generates direct current electric energy directly from the rotation of the drive means (28) rotating as a rotational function of the drive shaft (26) of the principal motor. The inverter means converts the energy received by the aggregation means from the recovery motor from direct to alternating current. The converted energy is fed through a service panel that connects the ventilation apparatus to the commercial power source through a utility meter to monitor the energy flowing to and from the facility and the power source.    USE - For recovering and generating electric energy from principal motors in a residential, commercial or industrial facility that utilize large-scale air conditioning and exhaust apparatuses on the rooftops e.g. of shopping malls and restaurants. Also used for the industrial sector where existing printing presses and other industrial machinery may be retrofitted to couple the principal motors to an associated recovery motor. The energy recovery system may also be used with other household mechanical apparatuses, including appliances, washing machines, furnace blowers and air conditions.    ADVANTAGE - The energy recovery system generates a stable and environmentally safe source of electrical energy to supplement increasing household, commercial and industrial electrical energy demands. The after-market energy recovery system has a recovery motor that is easily installed on the principal motors of existing apparatuses, machines and other devices. The recovery system is also incorporated at time of manufacture of the apparatus, machine or device for enabling the manufacturer to market the system as an energy efficient product. In the industrial sector, existing printing presses and other industrial machinery may be retrofitted to couple the principal motors to an associated recovery motor. A business in the industrial and manufacturing sectors will be able to reduce energy overhead costs through net metering and possibly generate sufficient electric energy to operate the secondary apparatuses within its facilities. The use of the motors within these facilities will create numerous sub-generating stations, which can be used to supplement the electric energy requirements of third party facilities and the commercial power source.    DETAILED DESCRIPTION - The recovery motor of the system may be any suitable motor which includes a multiphase, brushless direct current motor and a single-phase, brushless direct current motor. The horsepower of the recovery motor is less than the horsepower of the principal motor. An INDEPENDENT CLAIM is included for the method of recovering energy from one or more mechanical apparatuses, each having a principal motor and a drive shaft.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic diagram of an energy recovery system for generating electric energy in a building facility.    Energy recovery system (10)    Cooling tower (16)    Recovery motor (24)    Drive shaft (26)    Drive means (28)