Every now and then, an oil supermajor comes up with what they tout as a breakthrough in scientific research of renewable energy sources.

This month, it was ExxonMobil’s turn to report a breakthrough in advanced biofuels. Exxon said that it had found a way to make algae ‘fatter’, and those algae could become part of the (distant) future energy mix, could cut carbon dioxide emissions, and would not compete with food crops like other biofuel sources.

Exxon and Synthetic Genomics have been partners since 2009 in researching and developing oil from algae to be used as a renewable, lower-emission alternative to traditional transportation fuels.

By using advanced cell engineering technologies at Synthetic Genomics, the joint research team has just modified an algae strain to enhance the algae’s oil content from 20 percent to more than 40 percent, Exxon said.

But the U.S. oil supermajor was quick to note that, referring to the fatter-algae strain, “technology is still many years from potentially reaching the commercial market.”

If at some point in the future Exxon was able to produce commercial-scale biofuel from algae at competitive prices, it could potentially offer an alternative to electric vehicles, creating a renewable-source fuel and freeing the U.S. from the geopolitical issues like crude oil imports or lithium reserves in countries outside America, David Butler at Seeking Alpha argues.

That is, if cars in America still run on gas when Exxon hits the market with a biofuel from a source that is grown and made fatter in labs.

Back in 2013, Exxon said—after having spent US$600 million on developing biofuels for motor vehicles from algae—that success was still a quarter of a century away.

“We’ve come to understand some limits of that technology, or limits as we understand it today, which doesn’t mean it’s limited forever,” the then CEO of Exxon, Rex Tillerson, said.

Now a breakthrough in research has been achieved, but still, limits exist in taking the fatter algae out of the lab and into the car engines.

Oliver Fetzer, chief executive officer of Synthetic Genomics, said:

“One of the chief obstacles facing the adoption of algae as a scalable energy source has been the biofuels industry’s difficulty in producing sufficient volumes. It’s not enough to be able to produce amounts equivalent to a lake’s-worth of oil from algae when global oil consumption is a veritable ocean – 96 million barrels – every day, according to the International Energy Agency.”

According to Exxon, apart from transportation-related energy, the algae could also “potentially be processed in conventional refineries, producing fuels no different from convenient, energy-dense diesel. Oil produced from algae also holds promise as a potential feedstock for chemical manufacturing.”

Exxon is not the only oil supermajor that has been conducting biofuel research. Ten years ago, in 2007—three years before the disastrous oil spill in the Gulf of Mexico, UK’s BP selected UC Berkeley to lead a US$500 million energy research consortium in partnership with Lawrence Berkeley National Laboratory (LBNL) and the University of Illinois at Urbana-Champaign. The funding created the Energy Biosciences Institute (EBI), to which BP had pledged to contribute US$350 million. But at the beginning of 2015, BP exercised its contract option to pull nearly a third of its funding for 2015, pulling even more in the remaining two years, according to the Cal Alumni association at UC Berkeley.

In November last year, BP said that it was investing US$30 million in bio jet fuel producer Fulcrum.

The UK supermajor has been producing ethanol from sugarcane in Brazil since 2008, and has three ethanol production plants there. But sugarcane crop growing and harvesting impacts the environment and needs arable land, unlike Exxon’s fat-lab-algae.

Exxon’s research may be promising and hailed as a ‘breakthrough’ by the company, but in its own words, actual feasible deliverable commercial production is many years away.

Until then, the ‘transportation’ using algae could only be this surfboard made of algae processed into a different kind—and sustainable—“polyols” that replace the conventional petrochemicals used in making surfboards.