By Mary Bellis
Wolf Hilbertz, German architect and inventor is the father of sea-cretion, the electrolytic deposition of sea-shell-like minerals from seawater that creates a construction material. Hilbertz has found a way to use sunlight to turn the minerals in seawater into limestone for underwater and dryland constructions. What is sea cretion good for? -- building islands, ocean homes, and cities with self-sustaining technologies.
Currently, Hilbertz is planning a five year experiment to accrete an island, the Autopia Ampere, which will house, feed, and employ 50,000 inhabitants. Autopia Ampere involves deploying house-size wire frames connected to large floating solar panels on the Skerki Bank, in the Mediterranean Sea between Italy and Tunisia, where the island will be built/grown.
Hilbertz developed the sea-cretion method while an associate professor of architecture at the University of Texas and later at McGill University in Montreal. In his first public demonstration, Hilbertz saved a decaying wooden pier by growing sea-crete around them. He is now working together with the Negril Coral Reef Preservation Society, to grow five experimental "coral" reefs, three are using landline power, one is using a sacrificial anode to make wet-cell battery power from seawater, and the fifth is using solar power. The limestone structures in the sea will facilitate the growth of corals and provide habitat for fish and other coral reef species, the method is sustainable, environmentally safe, and economically and biologically feasible. Coral reefs are one of the most complex marine ecosystems, important to sea life and protective of shorelines from erosion.
Wolf H. Hilbertz is the subject of an extensive article titled "Ocean-Grown Homes" in the September 1997 issue of Popular Mechanics.
"Mineral Accretion of Large Surface Structures, Building Components and Elements," U.S. Patent No. 4,246,075,
(Jan. 20, 1981).
By establishing a direct electrical
current between electrodes in an electrolyte like seawater, calcium carbonates,
magnesium hydroxides, and hydrogen are precipitated at the cathode, while
at the anode, oxygen and chlorine are produced. The electrodeposition of
minerals is utilized to construct large surface area (i.e. greater than100
square feet) structures, building components and elements of a hard, strong
material (i.e. 1000-8000 P.S.I. compression strength). To make a large
surface area structure, building component or element of hard, strong material,
a preshaped form of electrically conductive material is disposed in a volume
of electrolyte, such as seawater, to serve as a cathode, one or more are
anodes disposed in proximity to
the form, and a direct electrical current is established between the electrodes for a period of time sufficient to accrete a solid covering of material on the form.
"Repair of Reinforced Concrete Structures by Mineral Accretion," U.S. Patent No. 4,440,605, Apr. 3, 1984.
By establishing a direct electrical current between electrodes in an electrolyte, such as seawater or fresh water containing minerals in solution, calcium carbonates, magnesium hydroxides, and hydrogen are precipitated at the cathode, while at the anode, oxygen and chlorine are produced. The electrochemical precipitation of minerals at and in the vicinity of metal reinforcement in a reinforced concrete structure is utilized to repair damaged portions thereof, for example, fractures, cracks, fissures, and voids. To repair reinforced concrete structures, the structure is disposed in a volume of electrolyte. The metal reinforcement is made a cathode by connection to the negative terminal of a suitable DC power supply. One or more anodes are disposed in proximity to the structure, and a direct electrical current is established between the electrodes for a period of time sufficient to fill by accretion cracks, fissures or voids in the concrete body of the structure.