The best replacement for solenoid is relay.

The best alternatives to solenoid are rated as following:
★★★★★  relay
★★★  starter
★★  electromagnet
★  coil
★  actuator
★  ignition switch
★  piezo injectors
★  inductor
★  motor
★  contactor
★  starter bad
★  servo
★  relay difference
★  ball valve
★  voice coil
  toroid
  starter motor
  bar magnet
  egr
  isolator
  double solenoid
  starter relay
  motorized valve
  battery isolator
  usdm vtec solenoid
  ac solenoid

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Speaking about solenoid, one probably shouldn't forget about starter.

Other search terms related to solenoid and their ratings are:
★★★★★ starter
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solenoid
relay
starter