Liquid Propane Gas (LPG)
While LPG cannot be considered as eco-friendly, it’s still the cleanest fossil-fuel source of energy. It is relatively easy to store (even in larger tanks) and transport, so it can be considered as one of the options for off grid houses. Frankly, in colder climate zones LPG may not have many viable off-grid alternatives when it comes to air and water heating (to some extent wind and hydro power can be considered as an alternative). Frequently seen practice of using wood-burning stoves (especially in the countryside and remote areas) is by far the least efficient and environmentally very unfriendly!
This off-grid Mica cabin located in Ontario (Canada) uses two 100lbs LPG tanks for cooking and heating (Solar panels provide electrical energy). Source: Exploring Alternatives (www.cabinscape.com)
Large above-the-ground LPG tank. Source: Lapesa (Spain)
The most popular off-grid alternatives for off-grid energy are PV panels, Heat collectors and recently wind-turbines. In practice however, none of them can guarantee continuous 100% supply of energy as all of them are very weather dependent. Short daylight time, cloudy or rainy days or still air may lead to even prolonged shortages of energy. Only hydropower is almost immune to weather (provided reasonable lengths of dry seasons).
To avoid frequent weather-dependent shortages of energy, off-grid locations may use hybrid systems. Combining PV with Heat-collecting panels is one of the most frequently used mixed configurations. However, as both depend on the same factor (sunlight) they do not provide better energy security, but rather optimize the use of resources (in this case the sun).
Much better alternative provides combination of solar and wind powers. When financial reasons (cost) and/or lack of relevant permits (wind, water) exclude feasibility of the hybrid system, the popular alternative is the backup generator. It’s usually affordable, although far from being eco-friendly (especially when running on diesel) and quite noisy, so if you go for that, it should be only used as a “last resort” solution.