Farming Freshwater Algae on the High Seas


If you have been paying even the slightest attention to the algae industry, you probably have heard of companies like Solazyme or Synthetic Genomics, the big names that are making big public strides in the field. Algasol Renewables, on the other hand, is one name in the industry that you have probably never heard mentioned. However, Algasol looks to be on the brink of joining those big names as one of leaders in the algae industry with their photobioreactor system.

Photobioreactors (or PBR’s) come in many different shapes, sizes, and designs. Essentially, they consist of some clear material formed in a way that it can hold an algae-containing liquid. Typically, you will find them looking like long tubes, snaking back and forth, that allow sunlight to reach the algae-water concentration that is pumped through it. They work great for growing algae but have typically suffered from high initial and operating costs.

This is where Algasol comes into play. They have designed a photobioreactor system that can potentially cut costs by 90 percent. How have they done this? Well, their thinking has taken them outside the tube and placed them into a bag.

Basically, their system grows freshwater microalgae in large plastic bags that float on top of bodies of saltwater. There, as in any other bioreactor, nutrients and CO2 are pumped in to feed the algae.

This design led Frost & Sullivan to give Algasol their 2010 “Global Algae Biofuels Award.” According to them, “Algasol Renewables provides a critical and innovative method for micro algae biomass production. Its modular floating bag technology, a new variation of photobioreactors (PBRs), provides a low-cost design coupled with industrial scalability, optimal light exposure, high biomass concentration, low energy consumption, and efficient system control.”

The oceans of the world have a great potential to be the location for floating algae farms. First off, oceans cover around 70 percent of the world. With land (especially agricultural land) becoming a very precious commodity, moving production of fuel offshore is a major bonus.

Additionally, the ocean cuts out a lot of the energy costs associated with traditional PBR’s. For example, the water surrounding the bags acts as a temperature buffer, a process that would require spraying down the outsides of the photobioreactor in typical systems. Also, the wave action in the ocean helps to mix the algae in the bags, something that would otherwise take additional energy in land-based designs.

Now, some may be concerned about putting all this plastic into the ocean should a storm comes along or worried about what happens if these bags break. Luckily, engineers at Algasol have addressed both of these problems. If a storm comes along, the bags have been designed to be submerged beneath the water to levels up to 250 feet. There, they can wait out a tropical storm, hurricane, etc.

Researchers are also not too concerned if one of the bags breaks. Since the algae will be freshwater species, they will die when exposed to saltwater and there, researchers have concluded, they can become food for fish and other marine life.

Their system has proven very successful in testing conducted in conjunction with Arizona State University. Right now, after taking account for the costs, they estimate that a 250 hectares (or 418 acres) system can produce oil at $1.40/gallon before refining, or roughly $60 a barrel.

These costs are actually calculated from the lower end of production levels (35 grams of algae per square meter). Algasol has achieved significantly higher production levels and higher productivity would potentially lower the cost even more. However, reaching these production levels rely more on outside factors than on the system itself.

“At the end of the day, we are dealing with a live organism here,” Miguel Verhein, Executive Director of Algasol said. “If this organism is not taken care of under the right conditions, then we can have a variation in productivity that is irrelevant to the photobioreactor system.”

Overall, Algasol is solely a technology company that, according to Verhein, “just wanted to make the best PBR based on CAPEX/OPEX and scalability.” As such, their goal is to sell their patented product and method to companies rather than produce the algae themselves.

This goal is quickly becoming a reality, with several organizations, including one large oil company, looking to purchase their technology. As with algae industry as a whole, all that seems to be required for Algasol to make it big is a little more time.

Article by Jonathan Williams, appearing courtesy Celsias.

About Author

Walter’s contributions to CleanTechies over the past 4 years have been instrumental in growing the publications social media channels via his ongoing editorial and data driven strategies. He is the founder and managing director of Sunflower Tax, a renewable energy tax and finance consultancy based in San Diego, California. Active in the San Diego clean technology community, participating in events sponsored by CleanTech San Diego, EcoTopics, and Cleantech Open San Diego, Walter has also been a presenter at numerous California Center for Sustainability (CCSE) programs. He currently serves as an adjunct professor at the University of San Diego School of Law where he teaches a course on energy taxation and policy.


  1. Eric Douglas on

    I like the concept, however I have questions about the possibility of leaking. The story talks about the algae being fresh water an exposed to a salt water environment. What brings questions to my mind is that the Great Lakes eco-systems have been ravished by invasive species many that are natural in salt water, zebra mussels, lampreys, smelt, and now phragmite reeds are choking off what little reminding coastal wetlands are left in the Great Lakes. All of these have been introduced by humans. How can we be certain that the algae can not adapt from fresh water to salt water the same way other species have?

    Maybe, someone with a background in marine biology can explain this better to me as I will be the first to admit that my knowledge on this is limited.

  2. What if the oil companies buy this technology just to stash it away unused? Are any biofuel producers buying this with concrete plans to put it straight to use?

  3. This is supposed to be about ENERGY. PBRs can not ever provide an alternative to oil.

  4. Photo Bio reactor uses to produce bio diesel from algae. There are many research and development in using Photo bio reactor to produce bio diesel from algae. Phycotech’s mission is to provide its customers with leading edge photo bioreactor technology.