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Combating climate change: can naval architects do more?

The Naval Architect: February 2020Climate

One way to get out of the climate change conundrum is to build in the sea what man has been building on the land. Floating complexes, be it offices or industrial estates, abodes or institutions, are environmentally more sustainable.

 

Living sustainably
Floating cities need no highways and bridges. That helps to reduce the enormous carbon footprint of the building material industry, which according to World Green Building Council amounts to 39% of global energy related carbon emissions.

 

What do you do with a building after it has served its purpose? Knock it down and build a new one in its place. On the water you tow it away, repurpose and give it is a new lease of life. Extending the life of a building is a ‘greener’ option that wastes less energy. Moreover, water transport is more energy efficient: to move 1000tonnes of material from A to B would require about 50 trips by truck but only one by a medium size barge with the power of one truck.

 

Urban Heat Island (UHI) effect is the blight of many cities. Air conditioners suck in the heat ejected by other air conditioners. On a floating structure, the heat of air conditioners is ejected directly into the water on which it floats. As the heat absorbing capacity of water (specific heat and thermal conductivity) is much higher than air, the physiological discomfort is less and the need for air conditioning reduced.

 

While land architects and engineers are dabbling with floating simple abodes, few have the credibility to develop working designs of complex mega floats. Below are examples of floating structures that could result in lowering carbon emissions…

 

Data Centre
The Internet of Everything will one day soak up 10% of all the energy produced in the world through data centres, just to keep the servers from overheating. These data centres eject heat into the atmosphere causing its own heat island, and guess what? Others around the heat island will attempt to counteract by having larger air conditioning systems, leading more heat emission.

 

For this reason, data centres floating in the sea make sense. Dumping heat into the sea by pumps and heat exchangers is more efficient than into the atmosphere with fans and cooling towers.

 

Floating nuclear power plant
The US alone has 83 nuclear-powered ships, 72 submarines, 10 aircraft carriers and one research vessel and Russia commissioned its floating nuclear energy power plant in December 2019. Nuclear energy is the cleanest base load energy system there is, but the image of the Fukushima nuclear disaster is still seared in the minds of too many for it to be taken seriously.

 

Such a nuclear reactor meltdown would not have occurred if the cooling water supply had not failed. A floating nuclear reactor sitting below the water line can hardly experience a meltdown as the cooling water system does not require external energy input to activate it.

 

Others
The superior sustainability of floating structures is not confined to energy related assets. Farm produce is more sustainable when grown on floating structures. Wind, sun and current are energies that can be harvested to support such farms and transporting farm produce in bulk is more energy efficient with barges than with trucks.

 

Industrial plants and warehouses should be erected offshore so that they need not compete for land, especially in high density urban areas. For the same reasons, infrastructures such as airports, shipyards and university campuses are also good candidates for offshoring.

 

Urban decay, a pressing problem in major cities, would be more manageable when cities are afloat than on land because structure can be removed, relocated and repurposed sustainably without resorting to the wrecker’s ball or explosives

 

Conclusion
A community that lives on the surface of water is more carbon neutral than its counterpart on land. Naval architects are well placed to take the lead in a movement to make better use of the seas around the world, as well as to combat climate change.