Propane (liquefied petroleum gas) is a versatile fuel used on homesteads for cooking, heating, Solar Water Heating, refrigeration, and backup power generation. Propane is stored as a liquid under moderate pressure and vaporizes when released. It has a high energy density of approximately 25 kilowatt-hours per gallon (91 megajoules per 20 pound tank). Propane is widely available in rural areas where natural gas is not.
Propane ranges and ovens are preferred by many homesteaders for cooking because they provide instant heat control and operate during power outages. Propane tankless water heaters provide unlimited hot water with 80 to 95 percent efficiency. Propane refrigerators use absorption cooling and operate silently with no moving parts. Propane space heaters are used for supplemental heating in cabins, workshops, and greenhouses. All propane appliances are rated by BTU input and efficiency.
Portable 20 pound tanks (barbecue size) are used for small appliances and camp stoves. Larger tanks from 100 to 1,000 gallons are installed permanently for whole-house systems. Above-ground tanks are less expensive and easier to inspect. Underground tanks are more expensive but are protected from physical damage and extreme temperatures. The tank is placed on a level, stable base, typically gravel or concrete, and located at least 10 feet from building openings and ignition sources.
A two-stage pressure regulation system is standard. The first-stage regulator at the tank reduces pressure from 200 psi to 10 psi. The second-stage regulator at the building reduces pressure to 11 inches water column (approximately 0.4 psi) for appliance operation. Copper tubing or black iron pipe is used for permanent installation, while flexible hoses with quick-connect fittings are used for portable appliances.
Propane is heavier than air and accumulates in low areas if a leak occurs. A propane gas detector is installed near the floor in any building with propane appliances. All connections are tested with soapy water or a gas detector after installation. Propane systems should be installed by a licensed professional in most jurisdictions.