Future Energy, Phytoplankton Farming, Carbon, Water, and the Value of Coastlines
Considering a future in which carbon is taxed and oil is expensive, it is likely that we will see a shift in sources of energy.
Let us quickly look at two proposals: Hydrogen Economy and CO2 sequestration:
Hydrogen is expensive to make, store and transport. It is unlikely to make a major contribution to the energy economy.1
CO2 sequestration has a fundamental problem in that the CO2 volume is substantially greater than the volume of coal or oil that it comes from. It will not be feasible to reinject the CO2 in the same place as the source of the hydrocarbon fuel that produced it.2 Putting CO2 into the ocean will result in toxicity unless it can be processed by photosynthetic organisms.3
So what will work?
First the issues:
Energy costs will increase.
CO2 needs to be removed from the atmosphere.
Since the cost of water is largely the cost of transporting it from where it is available to where it is needed, water of appropriate purity will become more valuable.
Land will remain valuable and in limited supply.
So what do I propose?
Consider a section of coastline and adjacent ocean. Let us suppose that the ocean area is used to grow (farm) (high lipid) phytoplankton and provide placement for electricity producing wind turbines. On shore let us consider placing water desalination, nuclear power and gas turbine peaking plants. Obviously water is available in substantial quantities, needing only appropriate processing to be useful.
The waste heat from the nuclear plant goes to the desalination plant as does any surplus generation from the wind farm. The concentrated brine effluent from the desalination plant is mixed with the cooling water exhaust of the nuclear plant to dilute it and render it innocuous. When the gas turbine peaking plant is run, the exhaust (Containing CO2) is run underwater to be processed by the phytoplankton. (Alternatively Hydrogen could be generated and stored for peaking use.) The phytoplankton in the cooling water intake is separated to provide biofuel oil and protein for feed. The whole process is essentially carbon neutral, producing electricity, potable water, fuel, and edible protein.
By considering the section of ocean used to farm the phytoplankton as a “farm” rather than as natural ocean, one understands that the ecology in this section of ocean is intentionally altered so as to be economically valuable and productive rather than being preserved as a “natural” ecosystem. Similar to what is done customarily on farmland. Presumably production will be augmented by appropriately fertilizing, culling and seeding.
Comments to Jim Easton.
2Consider Cetane (Hexadecane). It has a density of approximately .77 g/ml. and is approximately 85% carbon giving a carbon density of approximately .65 g/ml. Liquid CO2, on the other hand, while having a density slightly greater than water, is only 27% carbon, i.e. has roughly half the carbon density of Cetane.
CO2 is denser than methane, but, because they are miscible, they must be kept separate, making it undesirable to store CO2 in the same reservoir from which the methane was extracted.