Study finds biofuels are contributing to climate change, not mitigating it

Biofuels such as ethanol and biodiesel are not anywhere near as environmentally friendly as previously thought.

A study by researchers at the University of Michigan, published today in the open-access journal Climactic Change, has found that biofuels actually increase the heat-trapping carbon dioxide emissions responsible for global warming, despite their reputation for being a ‘clean’ fuel source.

It was previously thought that such fuels were carbon-neutral, based on the premise that the CO₂ they produce when burnt was balanced by the CO₂ the plants absorbed as they grew. However, this study has found that the crops’ CO₂ absorption only mitigated a fraction of its emissions.

Using extensive crop production data from the US Department of Agriculture, alongside data on fossil fuel production and vehicle emissions, the researchers found that during a time when biofuel use rapidly increased in the US, the biofuel crops’ CO₂ absorption only offset 37% of their emissions when burnt.

“This is the first study to carefully examine the carbon on farmland when biofuels are grown, instead of just making assumptions about it,” explained research professor and study lead author John DeCicco, from the University of Michigan Energy Institute.

“When you look at what’s actually happening on the land, you find that not enough carbon is being removed from the atmosphere to balance what’s coming out of the tailpipe.”

A vehicle owner tops up his car using the biofuel ethanol in Washington State, the US. The country has promoted biofuels as a green alternative for transport. Image courtesy of Carolina K. Smith MD / Shutterstock.com

A vehicle owner tops up his car using the biofuel ethanol in Washington State, the US. The country has promoted biofuels as a green alternative for transport. Image courtesy of Carolina K. Smith MD / Shutterstock.com

The findings have significant ramifications for climate change mitigation approaches, as biofuels have increasingly been used as a cleaner alternative to petroleum. In many parts of the world they form a vital part of government-backed plans to reduce carbon emissions; a role that may well need to be reconsidered now that such strong doubt has been cast on their effectiveness.

In the US, for example, they are recommended for transportation purposes by the US Renewable Fuel Standard, which has helped to spur growth in production in the country from 4.2 billion gallons in 2005 to 14.6 billion gallons in 2013.

The researchers have even gone so far as to argue biofuels are worse than other traditional fuel sources, due to the false sense of security they provide to policymakers.

“When it comes to the emissions that cause global warming, it turns out that biofuels are worse than gasoline,” said DeCicco.

“So the underpinnings of policies used to promote biofuels for reasons of climate have now been proven to be scientifically incorrect.”

Biofuels are often presented as environmentally friendly, such as in this concept image. This will now have to change as a result of the study's findings

Biofuels are often presented as environmentally friendly, such as in this concept image. This will now have to change as a result of the study’s findings

As a result of the shocking findings, the researchers are now recommending that policymakers reconsider their use of biofuels to mitigate climate change.

“Policymakers should reconsider their support for biofuels,” said DeCicco.

“This issue has been debated for many years. What’s new here is that hard data, straight from America’s croplands, now confirm the worst fears about the harm that biofuels do to the planet.”

Record-breaking device promises low cost, efficient solar energy storage

Researchers at  École polytechnique fédérale de Lausanne (EPFL) and the Swiss Center for Electronics and Microtechnology (CSEM) have designed a new device using commercially available solar cells, and none of the usual rare metals, that stores solar energy as hydrogen more stably, efficiently and at lower cost than all previous methods.

Solar energy is stored for periods without sun by converting the energy into hydrogen via electrolysis, using the electrical current produced by the solar panel to split water molecules into their hydrogen and oxygen components.

The hydrogen can then be stored for future use as fuel or to produce electricity. The issue encountered so far is that although there are hydrogen-production technologies with potential, they have been too unstable or expensive to be used on a commercial scale.

Image courtesy of Infini Lab / EPFL 2016

Image courtesy of Infini Lab / EPFL 2016

The method used by the EPFL and CSEM team involved a combination of components that have already been proven to be effective in the industry.

The researchers’ prototype consists of three interconnected, new-generation, crystalline silicon solar cells attached to an electrolysis system that does not rely on rare metals.

The device can convert solar energy into hydrogen at a rate of 14.2% and has so far been run for more than 100 straight hours in test conditions. This represents a world record for silicon solar cells, as well as for the production of hydrogen without the use of rare metals.

The team’s effort outdoes all prior attempts in regards to stability, performance, lifespan and cost efficiency.

“A 12-14m² system installed in Switzerland would allow the generation and storage of enough hydrogen to power a fuel cell car over 10,000km every year,” said EPFL researcher Christophe Ballif, who co-authored the paper and who also heads the CSEM PV-center.

solar

Traditional solar panels, which have seen growing worldwide use over the last decade

The key to the team’s success is two-fold, resting on both the efficient use of existing components and the employment of a ‘hybrid’ crystalline-silicon solar cell based on heterojunction technology.

The device is structured using layers of crystalline silicon and amorphous silicon that allow for higher voltages, meaning that with only three of these interconnected cells, it is possible to generate a near perfect voltage for electrolysis.

Additionally keeping the cost down is the usage of a nickel catalyst for the electrochemical part of the process. The concept was proven using standard heterojunction cells, but it is expected that by using the best available cells, they could achieve performance rates as high as 16%.

“We wanted to develop a high performance system that can work under current conditions,” said Jan-Willem Schüttauf, a researcher at CSEM and co-author of the paper.

“The heterojunction cells that we use belong to the family of crystalline silicon cells, which alone account for about 90% of the solar panel market. It is a well-known and robust technology whose lifespan exceeds 25 years. And it also happens to cover the south side of the CSEM building in Neuchâtel.”