The stuff we think of as pond scum could be the secret to fixing food scarcity and fuel security, but not until algae systems are less expensive and more efficient.
Earlier this month, English design firm ecoLogics Studio drew the attention of attendees at Expo Milano 2015 (this year's Universal Exhibition, neé World's Fair) when they set up a working prototype of their newest invention, the Urban Algae Canopy. With 390 square feet of cushiony flaps lined with tubes filled with a slurry of green algae and attached to a series of pumps, the canopies are meant to be the newest revolution in urban greening, gardening, and even fuel generation.
Programmed to react automatically to weather patterns or to manual commands from passers-by using a digital interface, the canopy pumps varied levels of water, air, and nutrients to the algae within it, generating more photosynthesis and thus more shade and greenery in the sun, or less when desired. The flaps can be moved about as needed. Providing dynamic greenery for cities is already a fairly cool invention, but beyond its aesthetic values, one canopy alone can purportedly suck up as much carbon dioxide and produce as much oxygen per day as 400,000 square feet of woodlands and generate 330 pounds of algal biomass, 60 percent of which (depending on the type of algae used) can be converted into food or current engine-compatible biofuels.
The promises made by the Urban Algae Canopy are enticing and impressive, yet this is only one of many projects looking to solve food and fuel security by plugging pond scum into high tech machines—the earliest such conceptions date back to the 1950s. Private firms and the US Energy Department alike have long touted the potential of algae (of which there are 100,000 strains, some toxic but some energy-dense, converting nutrients into natural oils that can be squeezed out and processed into biofuels) to produce anywhere from 10 to 500 times the oil of traditional crops like corn or soy. And they can do so, according to these promoters, on bad or useless land rather than farmland, using passive open ponds or networks of contained-system tubes, all while fixing carbon dioxide into oxygen to neutralize the future impact of their fuels.
Within the past few weeks alone, researchers have explored new technologies to use algae to clean up pig shit and turn it into protein-rich livestock feeds, and even to make surfboards, without relying on environmentally degrading polyurethane production. And just a year ago, the notoriously futuristic and ostentatious design firm Arup launched its own algae-powered urban energy solution in the form of an experimental Hamburg, Germany apartment building called the Bio Intelligent Quotient—a cube tiled in algae reactor plates, responding to sunlight with shade and pumping biomass into an incinerator to power the building and generate fuel or food for others in the city with its potential excess. And beyond these projects, the US government has invested millions per year under President Barack Obama (and even developed its own algae testing grounds) on algal energy. Even ExxonMobil has gotten involved in the research game, eager not to be left behind if this technological innovation takes off and displaces oil.
Yet given all this boosterism and the publicity around things like the Urban Algae Canopy and the Bio Intelligent Quotient, one has to wonder why we only hear about the future transformative potential of algae and never see it turn into consumer-ready technologies.
The reason turns out to be fairly simple (and classic in the green tech world): While algae can do all the wonderful things proponents claim, it can only do them via costly, inefficient processes.
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Setting up the infrastructure to contain algae systems like the Canopy is incredibly expensive (given that these systems require constant temperature control) and take massive tracts of land. One estimate holds that to replace just 17 percent of the gas we use in transit alone, we'd need to set aside a swath of land the size of South Carolina. And the least expensive systems (open algae ponds) lead many to fear that imported or genetically modified algae cultures could easily escape from these systems and wreck havoc in the natural environment. Even if we were to get the infrastructure for algae farming in place, algal colonies suck down massive amounts of water (50 percent more than we need to produce fossil fuels at best, but some estimates say we'd need to appropriate water equal to a quarter of what we use in total for agricultural irrigation to hit that 17 percent goal). They also require tons of nitrates and phosphorous as nutrient bases, both of which are getting more and more expensive with every passing day—just feeding the damned algal blooms can constitute up to 80 or 90 percent of the cost of the resulting biofuels. Then there's the problem of even finding the right strains that can survive mass cultivation.
Even when we manage to set up a functional algae farm or system, the energy-intensive process of harvesting it and wringing the oils or nutrients out of it can at times wind up generating more carbon dioxide than the colonies suck out of the air. And the high yields estimated based on lab results don't always translate into real-world systems. Plus, some worry that the resulting fuels wind up being weaker than standard fossil fuels. We don't yet know how all of these problems affect the Urban Algae Canopy, but we know in the case of the Bio Intelligent Quotient the end result was a cost of $2,500 per square foot to install a system that has at present only managed to achieve 50 percent (versus the promised full) energy self-sufficiency. We also know that the inefficiencies of algae technologies were the reason that a long-lasting Energy Department program, researching algal power since 1978, was shuttered in 1996.
Thankfully, this inefficiency is not an unchangeable reality of algae technology. Over the past couple of months, scientists have made great bounds in reducing the costs of harvesting and resource extraction by developing strains of algae that naturally clump together. And just this month, one research firm managed to bump the productivity of its systems up by 22 percent, making them more cost-effective and productive. In March, researchers at Rice University also published a paper showing that one can actually kill two birds with one stone by growing algae colonies in wastewater treatment plants, so that the colonies suck natural nitrates and phosphorous out of our sewage (the most costly stage of wastewater treatment at the moment), lowering both the cost of their care and of sanitation, and generating steady flows of food and fuel in the process. A similar system was actually installed in Alabama in 2013 and has met great success so far.
Even with all of these advances, no one thinks algae will rise to prominence immediately. The most optimistic boosters' estimates say that (modest) industrial production of algae can begin in 2018. But algae power is on its way in the long run. Unfortunately for design nerds, it just won't look like the futuristic (and experimental and likely prohibitively expensive) Urban Algae Canopy. It'll probably look more like pond scum on the top layer of a slurry of shit and piss, churning away somewhere in a sewage treatment plant. Still, even if the Urban Algae Canopy isn't coming to a city near you anytime soon, it's a fun way to explore advances in the technologies algae can someday fuel, and to get people talking about a faulty yet promising tech.
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