Algae in Paris Revisited

ORIGINAL: Green Building Elements

BY GLENN MEYERS

JANUARY 25, 2013

On occasion we publish letters on Green Building Elements. In this case, Kstor, writing from France, is critical of the energy promises made by Ennesys and Origin Oil in a Jan. 11 post about growing algae on buildings using wastewater to then generate energy. In spite of real optimism to generate renewable energy using a sustainable infrastructure, the criticism here is articulate and should be carefully considered by those intrigued by the promise of algae.

Photo: Algae floating from Shutterstock

Kstor writes:

The idea of growing algae on buildings using wastewater is not new. As a matter of fact, it originates from the French architect studio X-TU back in 2008 (and they have a patent on it), which will soon deliver the first prototypes of their biofacade concept in cooperation with a world-class French public laboratory on microalgae controlled cultures (see recent press releases and articles in French about it).

The problem here is more what Ennesys tries to achieve, when they promise to cover 80% of the building’s energy needs thanks to microalgae productivities of 150T/ha (see many other articles and their press releases).

Those figures are just not correct, as any microalgae specialist will immediately notice. These kinds of productivity are theorical, and can only be achieved in lab conditions with a 12 h direct flow of photons and constant temperature, pH, nutriments, carbon inputs, etc… In outdoor conditions, the maximum productivity in Paris would be around 30 T/ha with the most advanced intensified PBRs – which they do not have – as a scientific article clearly demonstrate: “Theoretical Investigation of Biomass Productivities Achievable in Solar Rectangular Photobioreactors for the Cyanobacterium Arthrospira platensis”.

It would be wise for Ennesys, and especially for their partners and investors, to “land on earth” and announce more realistic figures- unless they want to nourrish a greentech bubble…

Thanks for the letter. We invite Origin Oil and Ennesys to respond.

Thanks to Jean-Louis Kindler at Ennesys for this answer:

There is abundant scientific – both private and public – literature confirming the figures demonstrated a few decades ago by NREL / DOE in the US showing average yields in the range of 30 dry g/m2/day in outdoor facilities, not even using advanced intensified PBR’s (just type “microalgae yield per acre” in any search engine).

Your assertions are based on theories and furthermore on assumptions on our system’s configuration. Our system’s performance is being measured with our real size, outdoor demonstrator.

Green Building Elements (http://s.tt/1yWme)

ORIGINAL ARTICLE Source of discussion

Origin Oil & Ennesys Use Paris Building Wastewater to Grow Algae for Energy

BY GLENN MEYERS
JANUARY 11, 2013

This post provides an interesting glimpse at a recently opened Paris building that generates energy from wastewater. The companies involved in this venture: Ennesys and Origin Oil.

Photo: Ennesys

OriginOil and its energy systems partner Ennesys unveiled this pilot project at the high-rise La Défense area in Paris, which has 37.7 million sq ft of office space, where they are fusing two essential functions of the smart buildings of the future: energy generation and wastewater clean-up. They have developed a solution that converts wastewater from commercial buildings into energy.

Here’s a short video

Jerry Schranz, part of the public relations team, informed me this system takes wastewater from the building (that is derived from bathroom waste water, kitchen water, etc.). This water is then used to grow algae, which is nourished by wastewater. The Algae Appliance invented by OriginOil scientists, processes the water and algae to produce methane, which is then used to power the building. Importantly, the flat panel bioreactors (where the algae grows) can be used on vertical surfaces, so skyscrapers are a huge area of opportunity for this type of energy production.

Algae Appliance invented by OriginOil

Photo: Ennesys

While the French government has mandated that new commercial buildings must produce more clean energy than they consume and purify or recycle water, OriginOil views these conditions as laying favorable ground for its technologies to be broadly adopted.

Congratulations to Ennesys and Riggs Eckelberry, Origin Oil’s CEO, on this demonstration of sustainable energy.

Photos: Ennesys grand opening

A New Energy Source: Major Advance Made in Generating Electricity from Wastewater

ORIGINAL: ScienceDaily

Hong Liu, an engineer at Oregon State University, has developed greatly improved new methods to produce electricity from the processing of wastewater. (Credit: Photo courtesy of Oregon State University)

ScienceDaily (Aug. 13, 2012) — Engineers at Oregon State University have made a breakthrough in the performance of microbial fuel cells that can produce electricity directly from wastewater, opening the door to a future in which waste treatment plants not only will power themselves, but will sell excess electricity.

The new technology developed at OSU can now produce 10 to 50 more times the electricity, per volume, than most other approaches using microbial fuel cells, and 100 times more electricity than some.

Researchers say this could eventually change the way that wastewater is treated all over the world, replacing the widely used "activated sludge" process that has been in use for almost a century. The new approach would produce significant amounts of electricity while effectively cleaning the wastewater.

The findings have just been published in Energy and Environmental Science, a professional journal, in work funded by the National Science Foundation.

"If this technology works on a commercial scale the way we believe it will, the treatment of wastewater could be a huge energy producer, not a huge energy cost," said Hong Liu, an associate professor in the OSU Department of Biological and Ecological Engineering. "This could have an impact around the world, save a great deal of money, provide better water treatment and promote energy sustainability."

Experts estimate that about 3 percent of the electrical energy consumed in the United States and other developed countries is used to treat wastewater, and a majority of that electricity is produced by fossil fuels that contribute to global warming.