Ocean Upwelling

Otherlab, which is based in San Francisco, has developed a low-cost large scale upwelling technology under the U.S. ARPA-E MARINER Program for growing seaweed at terrestrial farming scales that might also be used to control ocean currents and create large upwelling zones of cold nutrient rich water. This might be used to cool local climate and shield glaciers and ice flows from warm waters, enabling the regeneration of ice cover over very large areas. Thermal energy moved is around 10,000 to 100,000 times greater than the required pumping energy. A large 10 megawatt upweller might provide up to 1 terawatt of direct cooling. The upweller looks like a ceiling fan and consists of a large rotor of similar cost and scale to a wind turbine rotor that is suspended beneath a surface float. Wave motion moves the surface float up and down which pumps the rotor around and other energy sources can also be applied. Device capital costs as low as $1000/(m3/s) appear achievable and a one gigawatt scale upweller farm might cost a couple of billion dollars and have an upwelling flow rate equivalent to around 3% of the Gulf Stream. By bringing large quantities of cool nutrient rich water to the surface upwellers can also greatly increase biological productivity which could help restore and increase fish stocks and whale numbers beyond pre-industrial levels. This can substantially help with social license, it can also potentially cover costs if the benefits can be adequately monetized.