As countries and their leaders strive to become eco-friendlier, researchers and environmentalists are proposing new sources of power in the form of bio-fuel. For example, in 2010, a twin-prop plane made the first 100% algal-fuelled flight at a Berlin air show — could this be the future? Together with Suttons, retailers of vegetable seeds, we look at the plants that are being tested as bio-fuels for the future of sustainable power.

What is bio-fuel?

Bio-fuels are sources of energy that are made from plants growing today. Although researchers are taking more interest in them in recent years, they are not anything new. Henry Ford planned to run his cars on ethanol and early diesel engines were once fuelled by peanut oil. However, once the cheaper alternative of petroleum was discovered, bio-fuel was set aside.

Now however, it has been realised that the use of fossil fuels is harmful to the environment, unsustainable and a finite resource — and focus has turned back to biofuels and renewable energy. In fact, in 2016, United Airlines announced that they’d be involved with a new initiative to integrate biofuel into its energy supply in a bid to reduce greenhouse gases by 60%.

Alga

‘Algae’ refers to a large, group of organisms. This ranges from microscopic cyanobacteria to giant kelp, they are typically aquatic and lack stems, roots and leaves. Researchers believe that algae could potentially produce up to 60 times more oil per acre than land-based plants — making it a strong contender for a biofuel provider.

Biofuel is generated by breaking down the cell structure of a plant and extracting the oil. Algae is favoured in this respect because it has thin cellulose walls, meaning that less energy is required to break down the structure compared to other plants.

Testing of algae as a biofuel has been in place for a few years. In 2012, Rolls Royce and EADS (now known as Airbus) announced that they were in the planning process of a wind, electricity and algal biofuel-powered plane. They said that this would be built by the year 2033 and produce an astounding 75% less carbon dioxide than the planes that are manufactured today.

In Germany, an algal-covered building exists. From its algae surrounding, the building can generate enough biofuel to heat itself and its water supply. The building currently reduces its overall energy needs by 50% and provides natural shading as it absorbs the sunlight. Jan Wurm, a specialist at Arup which was one of the companies behind the algal-covered building project, admitted that upfront costs were high.

Studies have shown that Europe needs around 0.4 billion cubic metres of fuel every year for transport purposes. To gain this from algae, over 9 million hectares would be required (about the size of Portugal), but scientists are looking at making the process more efficient.

Another advantage of algae as a biofuel is that it requires carbon dioxide to grow. This benefits the environment as it takes CO2 out of the atmosphere — unlike current fuel sources that emit the gas.

Switchgrass

Many people think that a better way of making biofuels is from grasses and saplings as these contain more cellulose (the component that is broken down to provide energy). One of these grasses is switchgrass, a native North American perennial grass (Panicum virgatum).

Cellulose is a structural component of the cell wall of a plant – it is a stringy fibre that has evolved to withstand decay. This feature makes it difficult to ferment into ethanol and into an energy source. Cellulosic ethanol is attracting attention as the greenhouse-gas emissions that are produced from this source are thought to be around 86% less than emissions from petroleum sources. This type of ethanol can also be produced from inedible sources such as fallen branches and woodchips — meaning that crops are not being produced for energy generation rather than consumption.

Switchgrass is becoming a feasible option to produce cellulosic ethanol as, unlike corn, the cellulose in switchgrass requires less energy from fossil fuels. Scientists have said that switchgrass provides five times as much energy as it takes to grow — an efficient way to create biofuel.

There is some contention to creating biofuels from plants as people say that the land would be better used producing edible crops for our growing population. However, this plant can be grown on acres of land that cannot support crop or food production — addressing this issue.

Sunflowers

Sunflowers are another option for a biofuel crop. The seeds from the flower are rich in oil and according to the National Sunflower Association, 1 acre of sunflowers can produce 600 pounds of oil.

The sunflower shares some features with other oil crops such as canola and soy – it grows well in a range of conditions, and can be grown easily on a small or large scale. The sunflower seed has a high oil content, often over 40%, making it an attractive choice.

Pacific Biodiesel, a company based on the Hawaiian island of Maui, is testing the effectiveness of the plant for energy. It only takes ninety days for the sunflower to go from ‘soil to oil’ and the plant can be used for a range of purposes; the oil is edible, fuel can be made, the by-product from the extraction process can be used as livestock food and the stalks can be crushed into building material.

One issue with mass sunflower production is that the plants can attract pests and disease. Processes such as crop rotation, wider row spacing to encourage air circulation and chemical control can help to manage these issues.

As we can see, there are some crops that are in the running to become our next energy sources. Of course, there is still research and development to be carried out in order to make the energy generation process more efficient and useable on a wider scale. Who knows what other plants we could discover as biofuel contenders?