While the majority of the UK’s domestic properties are connected to gas, there are currently up to four million homes that are unable to get mains gas and are considered ‘off grid’. And for homes that need to look for an alternative to gas to heat their homes, LPG is considered a good option. Cleaner than oil when it comes to greenhouse gas emissions, LPG – or liquefied petroleum gas – is also more a more efficient energy source. We take a look at exactly what is LPG and ask; it is right for your home?
What is LPG?
Liquefied Petroleum Gas LPG is a colourless hydrocarbon gas that has been pressurised into a liquid. It is actually a chemical mix of two non-toxic but flammable gases – propane and butane.
While LPG can be extracted from natural gas, it is typically an industry by-product of the crude oil refining process and unlike natural gas, doesn’t rely on a pipeline for transportation.
With a very low boiling point, at room temperature, LPG will evaporate back into a gas which is why it is stored in pressurised bottles, cylinders and tanks to prevent it from evaporating. It is in its liquified form that LPG is more efficient as it holds much more energy.
LPG can be used for a host of applications, including boilers and central heating as well as powering cars and other vehicles (where it is also known as autogas) and has a lower carbon footprint as it emits around 12% less CO2 than oil. It is also cheaper and is easily transported, making it a good alternative to oil-powered boilers and central heating systems.
Types of LPG: Propane vs. Butane
When it comes to types of LPG, it is based on the hydrocarbons used to produce it – propane and butane. Both are safe to be used for home appliances but due to their differing properties, can be used for different applications. And this will help to decide which is best to use – propane or butane.
As a liquid, propane has a lower boiling point (-42°C) than butane and so works better in lower temperatures, making it a good energy source choice for use when cooking in caravans or for patio heaters, or more commercial applications. And it also stores better outside than butane, making it a good choice for domestic heating, where the LPG is stored in a tank outside.
With a higher boiling point (-2°C), liquid butane is a good fuel for indoor environments, including use in central heating boilers, portable gas heaters and cooking appliances. Butane also provides more energy than propane.
Pros and Cons of LPG Central Heating
While LPG is an efficient fuel for your central heating system, especially if you are not on mains gas, it does have its pros and cons which you will need to weigh up.
- It is an easy-to-use alternative to natural gas if your home is not on the mains gas grid
- LPG is an efficient fuel, meaning it can result in lower home heating bills than oil or electric heating
- It is also cleaner than oil when it comes to lower carbon (producing around 20% less carbon emissions than oil) although it will still produce CO2 so not a clean fuel
- LPG boilers are typically cheaper to buy and install than oil boilers, and are quieter to operate
- As it behaves in a similar way to natural gas, LPG (used with an LPG boiler) can be used to fuel all the main domestic gas appliances, including central heating systems, hot water and cookers as well as fires
- LPG is a good companion fuel for renewable heating, including air and ground source heat pumps, for when insufficient energy has been generated
- LPG typically costs more per kWh than oil, although prices can fluctuate between the two
- As it cannot be supplied by mains like gas can, LPG will need to be delivered regularly and stored
- If your carbon footprint is a priority, LPG is not the cleanest fuel option to choose as it does still emit levels if carbon
- You can run out of your LPG supply unless you are organised – although you can buy a remote fuel level monitor to prevent this from happening
- You will need to have a storage tank installed or a store for the cylinders or bottles, which will take up precious outdoor space.
Storing LPG at Home
To ensure you have a constant supply of LPG, especially during the colder months, you will need to create sufficient storage space.
In most cases LPG is bought in bulk and so requires a large storage tank which must be located outdoors, in a garden or yard. The storage tanks can be unsightly, so you may choose to have it installed underground, which will add extra cost to your initial LPG boiler installation bill. However, it does mean it won’t take up topside space, as all you will see is a cover in the ground, through which your LPG supplier can refuel the underground tank as needed. Otherwise, an above ground tank will need to be secured onto a fixed base.
The benefit of a storage tank is that you can bulk buy your LPG, which is often cheaper than buying it by the bottle.
Storing LPG cylinders
If outdoor space is tight or you don’t want a large tank in your garden, you can choose to use the more portable cylinders, which can be kept in a smaller outdoor store. Small butane cylinders are ideal for stoves and patio heaters. For LPG boilers, however, you will need the larger propane cylinders, which should be 40kg or more. Care should be taken over handling the LPG cylinders, which should always be delivered by a reputable supplier, who will also take the empty tanks away.
Is LPG a Good Option for Your Home?
So, to finish on the big question – is LPG a good option for domestic use? The overriding factor in answering this question is whether your home has or doesn’t have mains gas.
If you are on the gas grid, then it is widely recommended to stick to a gas boiler. And the main reason is convenience and cost – with LPG you need to regularly have your supply delivered and then stored, whereas gas is consistently supplied on demand.
But if you are ‘off-grid’ when it comes to gas and are looking to install an efficient alternative fuel boiler that is cleaner and overall, more energy efficient than oil, then LPG is a good option and certainly worth exploring for your home.