The secret weapon that could be a game changer to heat our homes

Biofuel can be used to heat our homes, with little to no need for expensive modifications; and it can also be used to fuel cars and – potentially - planes.

In short, biofuel is a combustible fuel source that is derived from things like trees, plants, nuts or microorganisms rather than from traditional fossil fuels.

If you’re a driver, you’re probably already using it. When you fill your car at the pumps, you may have noticed an ‘E’ number on the signage. This tells you how much of the petrol is made up of biofuel – E10, for example, means that 10% of the petrol you’re using consists of biofuel. A few years ago, standard grade petrol switched from being E5 to E10, and the long-term aim of scientists interested in this field is for that number to rise further. We’d like to get to the point where cars are being filled entirely with biofuel, but even if we progressed to 50%, then we’ve halved the emissions your car would normally produce.

Since modern cars already use petrol which contains biofuel, most vehicles will be able to use a higher percentage of it without any significant modifications. Even electric cars leave a carbon footprint; they still require heavy machinery and heavy industrial processes which require fossil fuels – so having the option to use existing cars with ‘greener’ fuel, would be very significant. 

Biofuel could also be a game-changer when it comes to heating our homes. While some homes have made the transition from boilers to heat pumps, this technology comes at a significant cost. It’s also not an attractive option for poorly insulated homes. With only a small conversion in existing boilers, the use of Hydrotreated Vegetable Oil – produced from the kind of vegetable oil you use to cook your dinner, along with other food wastes – can reduce emissions by more than 85%.

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So what’s holding up our adoption of biofuel when there are significant advantages as a sustainable alternative? One of the challenges is production costs. At the moment, 100% biofuel is more than double the price of standard petrol. That’s where our research, and the research of scientific colleagues across the world comes into play.

To bring the cost down, we need to find ways to produce biofuel at a larger scale. At University of the West of Scotland, we’re looking to do that through obtaining it from microalgae; which naturally produces oil known as lipids. We’ve been using lipids to produce a highly versatile – and sustainable – biofuel. It’s important to point out that biofuel does produce emissions – it’s a combustible fuel, after all. The main benefit comes from the process to obtain it. In the case of our project, microalgae consume large amounts of CO2 – more than it produces, in fact – meaning that it goes beyond being carbon neutral and is actually carbon negative.

Researcher Dr Cristina Rodriguez (Image: UWS)

We’ve mentioned that biofuel can be obtained from the kind of algae you find in your garden – so we should address the elephant in the room – could you use this algae to produce biofuel at home?
In theory, you could – but the process to obtain it is complicated, and it’s very unlikely that you would be able to obtain enough biofuel for it to have any kind of practical use – which brings us to the challenge we face: upscaling our process.

There are more than 100,000 species of algae across the world, and we’re only using varieties which produce large quantities of oil. Our project is not about proving you can obtain oil from microalgae – it’s about proving it’s possible to run it at a larger scale; making it possible to create microalgae refineries, as opposed to petrol refineries, producing significant amounts of biofuel and creating jobs.

UWS researcher Callum Russell (Image: UWS)

When we talk about biofuel, it’s important to point out that we’re not suggesting it as an alternative to things like wind power, heat pumps and electric cars – it’s an ‘as well as’, not an ‘instead of’; another tool in our arsenal as we battle through a climate crisis. It’s also worth pointing out that other scientists are exploring different methods to produce it cheaply, as a large scale – and it’s worth keeping a very close eye on the work done in this field. It’s almost certain that an exciting breakthrough will be made in the near future. When that happens, its impact could be world changing.

Dr Cristina Rodriguez and Callum Russell are researchers in renewable energy and biorefineries in the School of Computing, Engineering and Physical Sciences at University of the West of Scotland.