In our galley, we use LPG (Liquefied petroleum gas) to cook by way of a gimballed stove.
The stove is fueled by a 5 kg (11 lbs) tank. pino houses two tanks with only one tank connected at a time, this way we can get a tank filled while the other is still in use. One 5 kg tank can last us two months, and less if we bake a lot.
We used to carry a 9 kg (20 lbs) tank which could last us 4-5 months, but had to recycle it in japan. Many countries don't want to refill foreign tanks, especially if they have an aged appearance. Throughout our travels we had to give up 3 tanks, 1 in New Zealand and 2 in Japan.
Our main tank lives in its own locker aft of the boat, with a drain hose leading down and off the stern. In the event of a leak, the gas will escape from this hose rather than filling the compartment and slipping down into the bilge. Our boat has a solenoid valve with a gas shut off that we can operate from inside the cabin, it is fitted with a sniffer and alarm to detect leaks. For safety, solenoids close in the event of a power failure. An LPG tank should never be stored inside. We store our secondary tank off the aft rail on a little platform we built.
Tank swaps. Many countries use a 'tank swap' system. You bring your tank when it is finished and swap it with another. This is a good system because the tanks are often made of painted steel and can corrode over time, especially if exposed to salt air. When swapped at a store, the steel tanks are re-painted and checked for problems, eliminating the need to do those checks yourself.
Keeping your own propane tank. If you prefer to have your own tank, a good alternative are aluminum or fibreglass tanks—although many places won't want to fill fibreglass tanks. If using your own tank for a while, you might run into issues with an over-filled tank (it happened to us). When exposed to the sun on a hot day (if tank is outside), the gas inside of the tank expands and will open the pressure release valve. Some LPG will escape from the valve to relieve the pressure in the tank. Don't handle the tank as it is offgassing. If the smell bothers you, pour some cold water over the tank to help it cool faster. The pressure release valve will close when the pressure has lessened, but may not with a faulty tank. To check for leaks on your tank, pour some soapy water over the tank. Bubbles will form around the leak.
Alcohol stoves. There are many alternatives to LPG. We tried cooking with an Origo alcohol stove in 2020, but we found that denatured alcohol was very hard and expensive to get in Canada. Not just this, most denatured alcohol was 50% ethanol (or less) with the remainder being made up of methanol and other burnable chemicals such as MEK and acetone, resulting it a less-than-deal burn. Alternatives like methyl hydrate(methanol) were plentiful but very dangerous to handle. Methanol is absorbed through the skin, stomach, or lungs and much of it becomes formaldehyde in the body, which changes to formic acid in the liver. Formic acid can cause death or damage to the brain or optic nerve leading to blindness. Methyl hydrate and denatured alcohol come in plastic, or metal containers(pour badly and rust). If you have access to affordable denatured alcohol or methylated spirits, cooking with alcohol is great. We found that it performs(boil time) just as well as LPG. The Origo stove has two cannisters, that each accomodate 1.2 L of fuel. Each cannister lasts 1 week of regular usage, this includes 3 meals a day, plus coffee and tea in evenings. Non-pressurized systems are simple and safe, but we could not make it work while in Canada.