Can algae save the world?

    Like all new technologies biofuels have their pros and cons. Scientists are working to improve them for the future – by developing new production processes and investigating alternative fuel crops. One surprise contender is… algae.

    Algae are water plants – some species are so tiny they can only be seen under a microscope. Algae absorb CO2 and store the carbon as oil. By growing algae in large numbers, scientists can create enough oil to make bio-diesel.

    Could algae save the world? How do algae biofuels stand up to our three climate-change-busting questions?

    Can algae biofuels really slow down climate change?

    Algae absorb CO2 from the atmosphere as they grow – just like other plants – and release the same amount when the algae biofuel is burned. But algae biofuels still have a carbon footprint. Growing and processing algae, then transporting the biofuel, requires energy. If this comes from fossil fuels, it all creates extra CO2.

    One big attraction of algae is they could potentially replace more fossil fuels than today’s biofuel crops. They don’t need as much space to grow, so we could make more biofuel with the land we’ve got.

     

    Do algae biofuels work in practice?

    The problem is, although small algae factories work well, scientists aren’t convinced they’ll ever be able to scale them up to full size. Some people argue we shouldn’t focus our attention on unproven ideas, when we could fight climate change using technologies we already have.

    What’s more, to be a realistic alternative to fossil fuels, algae biofuels will need to be affordable. The balance might change as oil becomes scarcer, or if carbon emissions are taxed, but recent estimates suggest algae biofuels will struggle to compete on price.

    Will algae biofuels do more harm than good?

    Algae need less space than other biofuel crops – and they don’t need fertile farming land either. Algae could be grown anywhere in ponds or factories. This might mean less habitat destruction, and less competition between food and fuel.

    It’s an exciting vision of the future, but there could still be drawbacks. The main fuel from algae would be bio-diesel – tests on today’s bio-diesel show an increase in some harmful air pollutants.

    And as algae biofuels are still under development, there could be other complications we just don’t know about yet.

    Find out more about biofuels in the future.