It’s already common to see solar-powered homes, gadgets, and even cars. And given the modernity of the world we’re in right now, it’s not far-fetched to say we’re gonna have industries powered with solar panels or other renewable energy in the future. 

But this one new discovery, which was published in the journal Nature Energy, takes the term “solar powered” to a next level: solar power fuel. 

Before you think of really sci-fi discovery, like maybe extracting actual sun ray into something liquid, it’s actually nothing like that (sorry to disappoint).  

What really happens is, researchers convert carbon dioxide and water into liquid fuels using their own solar-powered technology. They can then add the fuel directly to a car’s engine as drop-in fuel. 

In essence, the University of Cambridge researchers harnessed the power of photosynthesis to convert CO2, water and sunlight into multicarbon fuels in a single step. These fuels, ethanol and propanol, have high energy density and can be easily stored or transported. 

When compared to fossil fuels, these solar fuels are completely renewable, and they don’t produce carbon emissions. Moreover, unlike most bioethanol, they do not divert any agricultural land away from food production. 

For now, the technology is still at laboratory scale. However, the researchers say that their discovery is an important step in the transition away from a fossil fuel-based economy. 

Bioethanol, the current fossil fuel alternative 

As a fuel, bioethanol has been praised for its cleaner features compared to petrol, as it’s made from plants instead of the old fossil fuels. 

Most cars and trucks on the road today run on petrol containing up to 10% ethanol (E10 fuel). The USA is now the world’s largest bioethanol producer; almost 45% of all corn grown in the US is used for ethanol production. 

Since bioethanol requires a lot of land, many think that the cleaner alternative quality of this fuel is not worth the large land use. 

Lead author Professor Erwin Reisner said, “Biofuels like ethanol are a controversial technology, not least because they take up agricultural land that could be used to grow food instead.” 

Reisner’s research group has been developing sustainable, zero-carbon fuels inspired by photosynthesis, for several years. 

 

 

To refresh our memory, photosynthesis is a process when plants convert sunlight into food. Well in Reisner’s case, the team uses artificial leaves. 

So far, these artificial leaves have only been able to make simple chemicals, such as syngas. It is a compound of hydrogen and carbon monoxide that is used to produce fuels, pharmaceuticals, plastics and fertilizers. 

However, to make the technology more practical, it needs to be able to produce more complex chemicals directly in a single solar-powered step. 

With Reisner’s artificial leaf, the team can directly produce clean ethanol and propanol without the need for the intermediary step of producing syngas. 

Using artificial leaves to make solar fuels 

To make the artificial leaf produce more complex chemicals, the researchers developed a copper and optimized palladium-based catalyst. This way, the researchers could get more multicarbon alcohols ethanol and n-propanol. Both alcohols are high energy density fuels that can be easily transported and stored. 

This isn’t the first time when researchers have found ways to produce similar chemicals using electrical power. However, this is the first time that scientists have produced such complex chemicals with an artificial leaf using only the energy from the sun. 

The paper’s first author Dr Motiar Rahaman said that normally, when researchers tried to convert CO2 into another chemical product using an artificial leaf device, they would almost always get carbon monoxide or syngas.  

“But here, we’ve been able to produce a practical liquid fuel just using the power of the Sun. It’s an exciting advance that opens up whole new avenues in our work. Shining sunlight on the artificial leaves and getting liquid fuel from carbon dioxide and water is an amazing bit of chemistry,” Rahaman said. 

Since it’s just been recently developed, the technology is simply a proof of concept and shows only modest efficiency. Therefore, the researchers are working to optimize the light absorbers so that they can better absorb sunlight. 

Moreover, they’re also optimizing the catalyst so it can convert more sunlight into fuel. The researchers will work further in order to make the device scalable, turning a lab development into something that can produce large volumes of fuel. 

Reisner said, “Even though there’s still work to be done, we’ve shown what these artificial leaves are capable of doing. It’s important to show that we can go beyond the simplest molecules and make things that are directly useful as we transition away from fossil fuels.” 

 

 

What we can have for now 

Although it’s slightly a bummer that we can’t use the sci-fi-esque sun fuel for now, we can always have the current alternative that also looks like it’s from a sci-fi: solar-powered cars. 

It’s not the same as electric cars charged with solar-powered chargers. Mostly, they’re cars clad with solar panels, which make everything look futuristic. 

Now, even though I said these cars are our closest alternative to driving powered by the sun, they’re not widely available for now. However, it doesn’t mean that engineers and scientists have been quiet about it; they constantly try to make great solar-powered cars. 

For example, this new vehicle development by a team of students at Eindhoven University of Technology in the Netherlands. It’s not just a solar-powered EV; it’s that with the ability to clean carbon pollution from the air as we drive it. 

The Zem car 

This carbon eating sporty car is called the Zem. It’s suited with a carbon capture device on its underbelly. What’s more, the body of the car isn’t made from the typical materials—it’s made from recycled plastics using 3D printer. 

The students who built this car received help from partner sponsors for the materials. For battery, the Zem was supported by Dutch company Cleantron. Then, Watllab provided the solar panels, and the study of the carbon output was provided by SimaPro software.  

Zem is actually the acronym of “zero emissions mobility,” which is the team’s main goal. As the team worked on this innovative vehicle, they realized that achieving carbon neutrality was impossible without a new solution. So they decided they needed to find a way for the Zem car to remove carbon from the air. 

 

 

Eventually, the team utilized two filters on the underside of the car. This way, the car can capture carbon while it’s in motion. As the car moves, air passes through the filter while carbon dioxide sticks to it. 

Initially, the filters have to be emptied every 200 miles, but the Zem car team has already developed a solution to mitigate the potential hassle. So, the students designed an EV charging station that extracts carbon dioxide. The captured CO2 can be repurposed for other clean fuels or safely stored to keep it out of the atmosphere. 

Mass producing Zem? 

At this stage, Zem is a very promising prototype with many potentials that are yet to be developed or discovered.  

For instance, the carbon capture device currently captures only 4.41 pounds of carbon dioxide for every 20,000 miles. This number, while it sounds good, is only 0.04% of the average vehicle’s annual carbon and less than one-tenth the amount that the average tree absorbs annually. 

Looking ahead, the team wants to keep working on improving the Zem car to what they believe is its full potential: carbon neutrality. The students also want to set this car as an example to the industry of what is possible. 

Well hopefully, while we’re waiting for the hi-tech solar fuel, we’ll get to enjoy the Zem car soon. 

 

Sources

https://www.sciencedaily.com/releases/2023/05/230518120808.htm   

https://news.yahoo.com/college-students-develop-solar-powered-111500785.html