The best replacement for propane is natural gas.

The best alternatives to propane are rated as following:
★★★★★  natural gas
★★★★  oil
★★★★  electric
★★★  butane
★★  electric heat
★★  gasoline
★★  natural gas grill
★★  charcoal
★  electric water heater
★  kerosene
★  electric smoker
★  oil heat
★  gas
★  heating oil
★  kerosene heater
  green gas
  natural gas cost
  electric dryer
  fuel oil
  charcoal grill
  gas generator
  heat pump
  kerosene heaters
  natural gas btu output
  gas generators
  electric stove
  oil furnace
  electric forklift
  diesel generator
  electric hot water
  butane gas
  natural gas prices
  natural gas heating
  natural gas grills
  electric heat cost
  natural gas btu
  wood heat
  electric cost
  butane bbq
  wood fireplace
  gas heating costs
  natural gas cheaper
  butane stove
  natural gas bbq
  electric heating

Your alternative for propane is not listed? Suggest!
Speaking about propane, one probably shouldn't forget about diesel.

Other search terms related to propane and their ratings are:

★★★★★ diesel
★★★★ heat pump
★★★ nitrous
★★ natural gas
★★ natural gas grill
acetylene regulator
You have in mind a companion for propane and it is not yet here? Propose!

Google Trends

Scale is based on the average worldwide traffic of propane in all years. Click on graph for more.
natural gas