In Indonesia, many major household appliances run on LPG. You will soon know the advantages of LPG when the electricity goes out (as it often does) and you can still cook or heat water for a warm bath.
LPG (elpiji) is sold in tanks (tanki) from open-bed trucks which drive through neighborhoods most mornings. The drivers of the trucks call out “Gas, gas, gas”. You could also develop a relationship with a shop that sells LPG near your home, whereby you can call them up to deliver a full tank to your home. It is convenient to have an extra tank, so that if you run out of LPG, you have a backup to use until you can purchase another tank. Too often you seem to run out of gas right in the middle of preparing an evening meal or cooking your kids their favorite cookies!
The tanks are refilled at Pertamina facilities. You can also take your tank to a shop where they refill it. Before accepting the full tank, be sure that the seal on the top is in place. There should also be a small black rubber washer inside the opening at the top of the tank. You might want to keep an extra washer at home, as occasionally a bottle will be delivered without it. You will not be able to connect correctly or safely without it.
Smaller LPG tanks are used primarily for stoves and ovens. The cost to refill the tank will be written on the receipt, currently Rp 137,000 for 12 kg bottle and Rp 150,000 for a 15 kg bottle (Jan 2015). Some of the trucks that deliver to neighborhoods may sell you a less-than-full tank. If you're at all concerned about that, weigh the tank on your bathroom scale before accepting delivery.
One concern when using LPG is the possibility of explosion due to leakage. Be certain that you household staff recognize the smell of leaking gas and do not use a tank that leaks. Inspect the connecting hoses often to be sure they are not cracked or leaking.