In a futuristic Iceland farm growing algae for food

In the shadow of Iceland's largest geothermal power plant, a large warehouse houses a high-tech indoor farm unlike anything I've ever seen.

Beneath a strange pink-purple glow, illuminated panels hum and cylindrical columns of water bubble as a futuristic crop of microalgae grows.

It is here that Iceland's Vaxa Technologies has developed a system that uses energy and other resources from a nearby power plant to cultivate these tiny aquatic organisms.

“It's a new way of thinking about food production,” says general manager Christine Haflidason as she gives me a tour of the space-age facility.

For much of our history, humans have consumed seaweed, also known as macroalgae.

But its tiny relative, the microalgae, was a less common food source, although it was eaten for centuries in ancient Central America and Africa.

Scientists and entrepreneurs are now increasingly exploring its potential as a nutrient-dense, sustainable food.

About 35 minutes from the capital Reykjavík, the Vaxa site produces the microalgae Nannochloropsis, both for human food and as feed for fish and shrimp farming.

He also grows a type of bacteria called Arthospira, also known as blue-green algae because it shares similar properties with microalgae.

When dried, it is known as spirulina and is used as dietary supplements, food ingredients, 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.”

The Vaxa plant has a unique situation.

It is the only place where algae cultivation is integrated with a geothermal power plant that supplies clean electricity, supplies cold water for cultivation, hot water for heating and even pipes through CO2 emissions.

“You end up with a slightly negative carbon footprint,” says Asger Munk Smid-Jensen, a food technology consultant at the Danish Institute of Technology (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 a low-carbon flux of CO2 and nutrients, is needed to ensure the setup is climate-friendly, and he believes this is not easily replicated.

“There's a huge energy input to run these photobioreactors, and you have to artificially simulate the sun, so you need a high-energy light source,” he explains.

“My main takeaway is that we should use those areas (like Iceland) where we have low-impact energy sources to produce energy-intensive products,” adds Mr. Munch Smidt-Jensen.

Back at the algae plant, I climb onto a raised platform where I'm surrounded by noisy modular units called photo-bioreactors, where thousands and thousands of tiny red and blue LED lights fuel the microalgae's growth instead of sunlight.

They also get water and nutrients.

“More than 90% of photosynthesis occurs in very specific wavelengths of red and blue light,” explains Mr Haflidason. “We only give them the light they use.”

All conditions are strictly controlled and optimized through machine learning, he adds.

About 7% of the crop is harvested daily and quickly replenished by 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-3s, fatty acids and vitamin B12, Mr Haflidason believes that growing microalgae in this way could help address 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 startup Algiecel is testing portable shipping container-sized modules that contain photo-bioreactors that could connect to carbon-emitting industries to capture their CO2 while producing food and feed.

The crops are also used in cosmetics, pharmaceuticals, biofuels and as a substitute for plastic.

Perhaps microalgae can also be produced in space.

In a project funded by the European Space Agency, the Danish Institute of Technology plans to test whether a microalgae can be grown on the International Space Station.

Despite all the investment, there is still a long way to go before microalgae become a daily part of our diet.

It still needs a lot of development, according to Mr. Munch Smidt-Jensen.

He points out that the texture has no firmness. Meanwhile, the taste can be “fishy” if the algae is brackish.

“But there are ways around that,” he adds.

There is also a public issue.

“Are people ready for this? How do we make everyone want to eat this?”

Malene Lihme Olsen, a food scientist at the University of Copenhagen who studies microalgae, says their nutritional value needs more research.

“Green microalgae (chlorella) have a very strong cell wall, so it can be difficult for us to digest and get all the nutrients,” she says.

For now, she says microalgae is better added to other “carrier products” such as pasta or bread to help with taste, texture and appearance.

However, Ms Olsen believes microalgae is a promising future food.

“If you compare one hectare of soybeans in Brazil and imagine we have one hectare of algae field, you could produce 15 times more protein per year (from the algae).”

Back at the plant I see an unappetizing green sludge. This is the harvested microalgae with drained water, ready for further processing.

Mr Haflidason suggests I try it and after initial reluctance I try some and find it to taste neutral 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 foods, and in Reykjavík 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 foods you eat,” he says.