If there is gas reticulation in your area, gas hot water system is definitely a better choice than an electric hot water system. Per litre of water heated, gas costs less money to buy, and emits less greenhouse gas (CO2). Gas hot water systems generally heat water faster than electric systems too.
Gas vs electric: cost benefit
A gas hot water system will often cost more upfront than an equivalent electric hot water system. In fact, when shopping around you may find that the price difference is massive.
You need to remember though - water heating will account for around a quarter of your electricity bill when you use an electric hot water system. Throughout the course of the water heater’s useful life, the amount of money saved by using gas instead is huge, and will only become greater as electricity prices rise.
By switching from electric to gas, even accounting for having to perhaps connect to the gas network for the first time, a gas hot water system will usually repay its initial investment within two to three years via energy bill savings. All the money it saves you from then on is a bonus.
Gas vs electric: environmental benefit
A natural gas storage tank hot water system produces about three to four times less carbon emissions than an a comparable electric model. Electric water heaters can produce around 4.4 - 4.6 tonnes of greenhouse gases each year. To put that in perspective, the average polluting car will contribute around 2.6 tonnes per year. Considering how much focus there has been on reducing emissions in vehicles, and you can quickly see why the federal government’s phase out of electric hot water systems has been such an urgent issue.
In comparison, a gas system will put out around 1.1 – 1.3 tonnes annually. Obviously a straight solar boosted system will reduce this even further, but these systems will also be more expensive to buy, and require certain conditions to be met in order to reap the most benefit. When choosing a gas system, go for one with as many energy efficient stars as possible.
Gas systems are usually very quiet. The only noise you might expect would come from an exhaust fan or pump if your heater has one, so this makes a gas system an ideal choice if noise pollution is an issue.
Obviously you will need access to gas piping in your area. Even if you live in an area with access to gas, it is possible that your house may not be connected to the gas network; if this is the case, remember to factor this in when costing and obtaining quotes. Also be aware that even if you are connected to the gas network you may need to have additional piping added to supply your hot water service. Continuous flow gas systems may require a larger diameter gas supply pipe to be installed, because of the rate at which they draw gas.