The Ocean On-Ramp to the Hydrogen Highway

Figure 1

Hydrogen is the most abundant element in the universe and on Earth is found principally in water that in turn is the repository for 93 percent of the excessive energy of global warming.

Warming heat accumulates predominantly between the Tropic Cancer and the Tropic of Capricorn within 100 meters of the ocean’s surface.

The thermal stratification of the oceans facilitates thermal energy conversion that; cools the planet’s surface, that can be converted to hydrogen in an electrochemical process that sequesters carbon dioxide and mitigates ocean acidification.   

The following is a rendering of a Negative Emissions OTEC (NEOTEC) platform that gathers energy from the ocean’s surface to boil a working fluid in the aluminum condensers at the bottom of the image and conveys the latent heat of evaporation of the vapor to a depth of 1,000 meters. 

Figure 2

The platform is comprised of segments that contain solar panels that converted solar energy to electricity and on the underside as shown in Figure 4 contain wave accumulators that convert wave to hydraulic energy that is conveyed in the yellow tubes in Figure 3 to the yellow power units in Figure 1 and windmills per Figure 3.   

A triangular platform 735 meters on each side would produce 200 megawatts of OTEC power plus an additional 50 megawatts from the solar, wave and wind energy striking the 636,000 square meters of the ocean’s surface.

The solar, wave and wind power propel the platform and any excess electricity from the yellow, green and orange units shown in Figure 1 is conveyed into the deep to be utilized in the electrolyzers that are the vertical cylinders in Figure 5 below.

Figure 5

The bulk of the power supplying the electrolyzers, however, is derived from the latent heat of evaporation of the working fluid flowing through the turbine and generator set (the light and darker grey units) to the left of the electrolyzer in Figure 5, to produce hydrogen that is collected in the red piping.

Hydrogen produced at a pressure of 100 bar (1,000 meters) returns to the surface to the red circular tanks in Figure 1, logarithmically 70 percent of the way to the 700-bar required for use in hydrogen-powered fuel cell vehicles.

The residual vapor, after passing through the turbine, is channeled into the condensers at the bottom of Figure 5 where it releases its latent heat of condensation into the water and returns to a fluid that is pumped back to the surface to complete the cycle.

William Clay Ford Jr. says the three impediments to “The hydrogen highway” are infrastructure, cost, and volume.

The paper Economics of converting renewable power to hydrogen by Glenk and Reichelstein demonstrates that in some niche applications renewable hydrogen is already cost competitive.

The paper, however, uses Germany and Texas as examples and is based on intermittent power sources, whereas ocean thermal energy conversion is constant and therefore between 3 and 10 times more effective.

As to volume, the paper Negative-CO2-emissions ocean thermal energy conversion estimates twice as much energy as is currently derived from fossil fuels can be derived from the oceans.

Although Ford’s concern is the transportation sector, hydrogen is an energy carrier that can service all of the world’s energy needs as well as a significant part of its demand for sustenance.  

The paper Impacts of historical warming on marine fisheries production shows the seas near China and Japan have seen fish population declines of as much as 35 percent between 1930 and 2010 exacerbated by increasing water temperatures and declining oxygen content. Both of which are remedied by NEOTEC that reduces surface temperature and produces oxygen as a byproduct of the electrochemical production of hydrogen.

The global gross world product for 2018 is projected at $87.51 trillion.

As Figure 6 demonstrates about 60 percent of this economic opportunity is produced by the Asian nations that have the greatest idle access to and need for ocean-derived energy.  

Figure 6

Source International Monetary Fund 2017

They are missing out on a tremendous opportunity to power and feed themselves.