Algae garden





©AlexandraArènes et AxelleGrégoire

The Story of the Chimera

The story of the Chimera, an old Greek myth about a creature part lion, snake and
goat, highlights how the imagination and self can thrive when unexpected elements
are brought together. With this installation, we sought to draw upon this notion and
connect it to the history of the site in question. Copenhagen has a strong historic
relationship to its waters. Once the province of fishermen and merchants, today they
offer a way to confront the challenges the city and world face. How is it possible to
produce energy in a sustainable, creative way ? This installation explores this
problem, juxtaposing and intertwining science, mythology, and nature.

Science, Mythology and the Sea: their interaction and opposition.
Algae is at the heart of the installation. It covers a large canopy and forms the
installation’s centrepiece. The algae’s growth creates a thriving, self-sufficient
ecosystem. The technology employed acts as a catalyst, spurring on its growth.
Though this form of bio-energy production is not the most efficient generator of
electricity, it grounds the installation firmly in Copenhagen’s water and its history. The
algae’s ecological universe unfolds in the installation’s garden, a closed and ordered
entity similar to the Greek cosmos. However, unlike a traditional garden, this garden
is inhabited, alive. It is constituted by the ecosystem’s different parts and therefore
embraces the entropy, the chaos which such a space can possess. It represents and
is occupied by the imaginary, mythical creature : the Chimera. There are also
transient organisms living under the algae’s surface. Science thus recalls an old myth
through constructing this world.

How does this world function and to what end ?
The environment is autonomous, complex like all living organisms, and is able to
evolve and change in unexpected ways. The technique used, nonetheless,
guarantees a high level of safety for the visitor. The unpredictable, shifting aspects of
the installation are present in the development of new spaces, experimental
hybirdisation, the unforeseen growth and adaptation of different plants and the arrival
of new insects and small mammals. A micro-climate exists between the ground and
canopy. The tubes resemble a greenhouse, reheating the air below. Rain water is
collected and recycled as a mist, producing a humid atmosphere for the plants. Light
is also filtered through the tubes. Such a fertile environment provides the ideal
conditions for plants to grow.
Algae therefore proliferates on the surface of the water. The visitor finds herself
under an ocean of algae, placed above her head, light filtered through the algae and

its water. She is submerged in an unrecognisable environment. The canopy is the
sky and this sky is a moving, living sea.
At each stage of the algae’s life cycle, the algae proves to be of benefit to the
installation and its ecosystem, in birth and death. It may be helped along
mechanically, but the algae produces, refertilises, recycles and harnessess the sun’s
The installation seeks to explore and develop further the methods used to produce
energy with algae. The manufacturing of energy is connected in this case to a
broader ecosystem. The algae is contained in tubes; the water, however, is kept
clean and filtered by shrimps and tiny organisms, removing the need for a
mechanical filter. The ecosystem cleans the water which in turn is directed through
the algae’s tubes. When the algae is formed through photosynthesis, it releases
hydrogen. This chemical reaction can be transformed into electricity through its
capture in batteries. It can consequently be connected to the local power grid. While
this collection is happening, the micro-algae’s different elements are separated by
gravity. This process generates an oil, a biofuel, which can be used as fuel for boats.
Biomass is also produced, providing an effective feriliser. Further, the water used is
recycled. Algae is an effective fertiliser in agriculture, improving the growth-potential,
resistance and quality of the plant being grown. The biomass created by the algae
will be reused in the installation’s garden, the purpose being to avoid the use of
pesticides and chemical fertilisers. The presence of plants can also purify the soil,
absorbing pollutants like metals and oil residue.

Scenographic experience
On the Surface – A large green layer of algae tubes, a sea seemingly taken over by
machines, offers the opportunity to learn about the process in question.
The canopy resembles the sea, mimicking its movements rhythmically and refracting
any natural light – a window to the sky.
The canopy acts as a shelter, protecting the garden and its ecosystem from strong
sunlight or sudden changes in climate.
Under the Surface – Entering the installation recreates the feeling of diving into the
sea, of being underwater.
Three different gardens form the route through the installation: a garden full of
stones, similar to the sea bed;  a humid garden filled with chimera plants; and thirdly
the garden found on Mount Chimaera, a mountain connected to the myth of the
Chimera, encased, fossilised in concrete.
The narrative each garden constructs lead the visitor to search for traces of the
Chimera, the imaginary creature.

The installation and its algae therefore imaginatively confront a host of challenges,
aware of their affect on and consequences for the global environment. They
cooperate in symbiosis with their geographical location, its specificity and history. By
combining such elements together, the Hybrid Garden revives with purpose the spirit
of the Chimera underlining its contemporary significance.

Bioproduction of hydrogen by the photosynthesis of microorganisms.
Bioproduction of hydrogen converted into electricity in batteries. The hydrogen is
produced from the sun and water by the photosynthesis of microalgae
(Cyanobacteria) grown in photobioreactors. (research stage)

Annual energetic estimation
384 MWh (383 790 kWh) per year
(calculation based on an estimated production of 27.5 toe / ha / year (figure derived from the
average estimated by the research: between 15 and 40 toe / ha / year)
(1 toe  = 11630 kWh)

Structure: tubular welded steel elements, galvanized white. Thickness: 10 cm. height:
from 3 to 5 m. quantity: 715
Photobioreactor (algae culture glass tubes + secondary structure) : 7731 tubes
(lenght : 3 m, diameter : 20 cm)
Manufacturer of the technology incorporated in the design : IGV Biotech
1. Tubular module system
2. System vessel
3. Circulation pump
4. CO2 supply interface
5. Piping system
6. Process control system and visualization 7. Sensors
8. Harvesting system
Biosphere : glass tubes (linear : 3215, diameter : 35 cm)
Storage building for the battery, electric transformer, 200 m2
Windmill (water pumping) : 6 units
Appendices built related to the technical water circuit operation : 12 units
Plants. Surface area of plants : 11 165 m2. Species : poinsettia-tree, hosta,
dieffenbachia, Cornus_alba, chrysanthème shamrock, chlorophytum comosum,

Concrete (ground) with « fossil » inlay (textures) : 3745 m2

Environmental impact
The algae preserves treated freshwater by only using seawater. It can adapt
effectively to an urban context and continues to thrive in polluted waters, because of
its development away from the ground. Unlike other biofuels, it does not require
agricultural space for its production, preserving any pre-existing food production. It
may even be possible to grow food under the algae’s canopy. Algae further absorbs
carbon dioxide, assisting in the fight against climate change. The algae’s
development is the equivalent of a growing forest. It is able to survive in extreme
tempertures, for instance in the arctic regions.