Submarine Geothermics; Hydrothermal Vents and Electricity Generation

Abstract

Ocean Ridges are areas with extremely high heat flow, where temperatures above 300 °C can be reached at shallow depths. These high temperatures make them a good target for exploitation of geothermal energy. Therefore, innovating designs to generate electricity installing a little submarine on top of the vent with a binary cycle plant have been developed as part of the activities of the IMPULSA project of the Universidad Nacional Autonoma de México (UNAM), which is focused on the utilization of renewable energy sources for desalination of seawater. Here, we present the results generated by the project for the exploitation of submarine vents and describe the designs that include calculations of the efficiency of every component.

The plants were designed based on typical values of the vent parameters, and a rough calculation is made about the electricity that could be generated from this renewable resource. The importance of the vents from the ecological and biological point of view restricts the amount of areas that could be used to generate electricity without any drilling, and it is considered that only 1% of the already known sites might be exploited. Under those conservative assumptions, some 130 000 MW of electricity could be generated. That is almost the same amount of geothermal power that could be generated inland with all the actual and new techniques to generate electricity. We conclude that prototypes must be tested and exploration of suitable sites must be performed for future electricity generation from hydrothermal vents. One important result, obtained with this research, is that from one hydrothermal vent, up to 20 MW of electricity can be produced with a simple method that does not affect the ecosystem.