In the shadow of Iceland’s largest geothermal power plant, a large warehouse houses a kind of high-tech indoor farm unlike anything I’ve ever seen.
Under a strange pink-purple glow, illuminated panels buzz and cylindrical columns of water bubble away, as a futuristic crop of microalgae grows.
Here, Iceland’s Vaxa Technologies has developed a system that harnesses energy and other resources from a nearby power plant to grow these tiny aquatic organisms.
“It’s a new way of thinking about food production,” says general manager Kristinn Haflidason as she takes me on a tour of the space-age facility.
For most of our history, humans have consumed seaweed, also known as macroalgae.
But its tiny cousin, microalgae, was a rarer food source, although it was eaten for centuries in ancient Mesoamerica and Africa.
Now scientists and entrepreneurs are increasingly exploring its potential as a nutritionally rich, sustainable food.
About 35 minutes from the capital city of Reykjavik, the Vaxa site produces Nannochloropsis microalgae, both for human food and for fish and shrimp farming.
He also grows a type of bacteria called Arthospira, also known as blue-green algae, as it has similar properties to microalgae.
When dried, it is known as spirulina and is used as a dietary supplement, food ingredient, and as a bright blue food coloring.
These tiny organisms photosynthesize, capturing energy from light to absorb carbon dioxide and release oxygen.
“Algae eat CO2 or convert CO2 into biomass,” explains Mr Haflidason. “It’s carbon negative.”
Vaxa’s facility has a unique situation.
It is the only place where algae cultivation is integrated with a geothermal power plant, which supplies clean electricity, delivers cold water for cultivation, hot water for heating, and even prevents CO2 emissions through pipes.
“You end up with a slightly negative carbon footprint,” says Asger Munch Smidt-Jensen, food technology advisor at the Danish Technological Institute (DTI), who co-authored a study assessing the environmental impact of Vaxa’s spirulina production.
“We also found a relatively low footprint, both in terms of land and water use.”
Round-the-clock renewable energy, plus CO2 flow and low-carbon nutrients, are needed to ensure the plant is climate-friendly, and he doesn’t think it’s easy to replicate.
“There is a huge energy input to run these photo-bioreactors, and you have to artificially simulate the sun, so you need a high-energy light source,” he explains.
“My main conclusion is that we should use these areas [like Iceland] where we have energy sources with little impact on the production of energy-intensive products,” adds Mr. Munch Smidt-Jensen.
Back at the algae factory, I climb up to an elevated platform, where I’m surrounded by noisy modular units called photo-bioreactors, where thousands upon thousands of tiny red and blue LED lights stimulate the growth of microalgae, instead of sunlight.
They are also supplied with water and nutrients.
“More than 90% of photosynthesis occurs within very specific wavelengths of red and blue light,” explains Mr Haflidason. “We just give them the light they use.”
All conditions are strictly controlled and optimized by machine learning, he adds.
About 7% of the crop is harvested daily and quickly regenerates with new growth.
Vaxa’s facility can produce up to 150 metric tons of algae per year, and plans to expand.
As the crops are rich in protein, carbohydrates, omega-3 fatty acids, fatty acids and vitamin B12, Mr Haflidason believes that growing microalgae in this way could help solve global food insecurity.
Many other companies are betting on the potential of microalgae – the market is estimated to be worth $25.4bn (£20.5bn) by 2033.
Danish start-up Algiecel is trialling shipping-container-sized portable modules housing photo-bioreactors that could be connected to carbon-emitting industries to capture their CO2 while simultaneously producing food and animal feed.
Crops are also used in cosmetics, pharmaceuticals, biofuels and substitutes for plastics.
Perhaps microalgae could also be produced in space.
In a project funded by the European Space Agency, the Danish Institute of Technology plans to test whether microalgae can grown on the International Space Station.
Despite all the investments, there is still a long way to go before microalgae become an everyday part of our diet.
According to Mr. Munch Smidt-Jensen still needs a lot of development.
He points out that the texture lacks firmness. Meanwhile, the taste can be “fishy” if the algae is a salty species.
“But there are ways to overcome that,” he adds.
There is also a social issue.
“Are people ready for it? How do we make everyone want to eat this?”
Malene Lihme Olsen, a food scientist at the University of Copenhagen who researches microalgae, says more research is needed into their nutritional value.
“Green microalgae [chlorella] they have a very tough cell wall, so it can be difficult for us to digest and get all the nutrients,” she says.
For now, he says, microalgae are better added to other “carrier products” like pasta or bread to improve taste, texture and appearance.
However, Ms. Olsen believes that microalgae are the food of the promising future.
“If you compare one hectare of soybeans in Brazil and imagine if we had one hectare of algae fields, you could produce 15 times more protein per year [from the algae].”
Back at the factory, I look at the tasteless green sludge. These are harvested microalgae with squeezed water, ready for further processing.
Mr. Haflidason offers me a taste and, after initial reluctance, I try a little and find it neutral in flavor with a tofu-like texture.
“We are absolutely not suggesting that anyone should eat green sludge,” jokes Mr Haflidason.
Instead, processed algae is an ingredient in everyday food, and in Reykjavik, a bakery makes bread with Spirulina, and a gym puts it in smoothies.
“We’re not going to change what you eat. We’re just going to change the nutritional value of the food you eat,” he says.
