Thoughts on Future Energy Sources

Sir David Attenborough has pondered what would have happened if the great minds of the industrial revolution had turned their thoughts to producing alternative energies beyond coal and steam power.

Historically, economics always seems to outweigh social and environmental considerations.

Hero of Alexandria described steam power in the first century AD. However, the economics of using this technology did not appear to make sense until manual labour became an increasing cost.

The sun is an almost infinite resource which provides us with an array of different forms of energy. This never actually disappears. It only changes form. There are now many “alternative” forms of energy that can be harnessed locally.

The economics of using a mix of “alternative” energy sources may now be preferable to building power lines to service aquaculture sites.

There are a range of established ways to capture and store energy. The most obvious being solar voltaics, wind power, hydro electric dams, wave power and geothermal. However, there are also other options available to innovative aquaculture ventures.

For example, solar ponds utilise the density stratification that  occurs when salts sink in saline water. The sun heats the salt which cannot rise because of its density. This heat can be used to produce steam power.

In addition, mixing of salt water and fresh water produces salinity gradient power.

Also, when acidic water meets alkaline water, the flow of hydrogen protons creates an electric current. Note that rainwater is acidic.

Power can be produced close to its location of use and can be stored in these systems which are essentially batteries.

Fermentation of “waste” products produces methane. This greenhouse gas is a biogas which can be used as a fuel rather than being released into the atmosphere.

Biofuel research is now progressing and may well be a major driver of the aquaculture industry, both as a product and as its own source of energy.

Plants and algaes produce energy from photosynthesis. They do it everyday. They reproduce every day, providing a renewable resource. Millions of years ago they did the same thing and locked up carbon when they became fossils.  This however, is a finite resource. 

Mankind’s solution to the increasing energy crisis was and still is… predominantly dig up, and burn the fossils under our feet. That produces heat, but releases carbon dioxide. Some of the stored energy is lost as the heat is converted to another form of energy (say electricity). Then high infrastructure costs are incurred in order to transport the energy. Then more energy is lost it as it travels along power lines.  Then even more energy is lost as one form of energy (say electricity) is again converted to another form (say light). For example, until recently, 90% of the energy released from light bulbs was given off as heat.

Ironically, the carbon dioxide produced from burning fossil fuels is the very thing used to produce microalgaes.  Algaes produce useful carbohydrates and lipids rather than allowing this greenhouse gas into the atmosphere.

Energy is one of the major costs of production. Surely it makes sense to produce energy close to where it is required.  This logically should be the main solution, not an “alternative”.

Historically mankind always seems to raise the bar when we need to feed our increasing population.

We need to start raising it now.

In addition to producing cheaper and more ecologically sustainable energy, aquaculture enterprises can also be designed to use less manufactured energy and utilise natural energy much more efficiently.

© Martin Hernen 2016



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