The Tidal Irrigation and Electrical System

The Royal Society’s report on geoengineering schemes was a disappointment. In it’s analysis of different ideas to mitigate greenhouse gasses in the atmosphere it focused on only part of the problem. Right at the beginning of the report it says that it will focus on schemes that divert solar energy into space or absorb CO2 from the atmosphere but focusing in this way creates false dichotomies and may cloud the climate change debate rather than illuminate it. The reason why we have all this CO2 in our atmosphere is due to our use of fossil fuels. If we found ways to produce our power without their use, then the problem could either go away or call for much more limited geoengineering interventions. The Royal Society’s report however completely failed to look at the issue of renewable energy. This is ironic given that wind, hydro and wave all can generate Carbon Credits by offsetting fossil fuel use and this is one of our biggest incentives for these industries.

As to the specifics of how the report dealt with the Tidal Irrigation and Electrical System; to put it simply it didn’t. It generalized all systems which utilize deep ocean water (DOW) into one broad category and in that category they only looked at the potential to transport CO2 from the atmosphere to the seabed. This is a great shame because systems which exploit DOW produce power and biomass on large scales. The Tidal Irrigation and Electrical System is the first renewable energy system which has proposed trying to capture the biomass component of the OTEC process. The utilization of these biomass resources can lead to less fossil fuel use and this is because they go into everything from fertilizer to food to plastic to the lights in our city’s and the fuel in our cars. However, this does mean that the biomass generated is not being stored on the sea floor so by the logic of the report it did not do much to offset climate change in that manner.

One idea that the Royal Society is interested in that this author feels desereves special derision is that of “artificial trees”. In proposal, these man made structures would litter our planet by the million. Their sole job is that of absorbing CO2 from the air. They produce nothing and rely on energy intensive processes in their construction and in either the storing of CO2 or the manufacture of the chemicals which are used to absorb the gas. The same problems that face other mechanical or chemical storage methods for capturing atmospheric carbon such as the ones that are proposed for coal burning power stations. A further criticism of artificial trees is that there is only a small economy of scale in the in industrial processes which underpin the concept. None of the designs become more efficient as they grow in scale. It does make this author wonder if it wouldn’t be better to build wind turbines in everyplace they are thinking of constructing one of these things. That might mean that the carbon emitted by the burning of fossil fuels was never released into the atmosphere in the first place.