Description cont.
By choosing a location with minimal (say 0.3%) density difference between hot, salty surface water and cold, less-salty, deep water, a head of 2.5 metres is sufficient to circulate large volumes of hot and cold water. Only for 10 days per year are ocean conditions unlikely to generate circulation.

In addition to transferring heat, the OHS also transfers oxygen to below the anticline, helping to prevent the anoxic conditions which are predicted as one of the by-products of Global Warming.

At full capacity, the machine is shifting more than 1.2 TeraWatts of heat, equivalent to the output of 600 central power stations.

Although rather more complicated than the HWC, the OHS has several advantages:

• For the same amount of wave energy, it circulates 30% more heat (because of density differences, it is easier to lift cold water than sink hot water).
• The cold water plume at the surface has significant effects on the weather.
• With the cold water come nutrients which stimulate phytoplankton, absorbing vast quantities of CO2
• Fish thrive. Couple that with Marine Park status and you have an oasis for fish revival.

It should be appreciated that although the great ocean currents (eg the North Atlantic Conveyor) move vastly more water, the temperature difference is minimal, since the surface water has to cool to almost 0ºC before it can descend by natural convection. Thus a few OHS machines will move an equivalent amount of heat on an annual basis. The OHS will be anchored and allowed to rotate to maintain a slight angle to the prevailing waves. It will be located where:

• Ocean surface is hot and salty
• Thermocline is not too deep
• Deep currents exist to diffuse the warm plume
• Surface currents exist to diffuse the cold plume
• The cold plume has beneficial effects on the local weather.

ie. in conditions typical for the Pacific ocean at 20ºN

Impact

• Each machine redistributes 220km3 of water per year equivalent to 670 GigaWatts continuous
• 600 such machines could mitigate our current Global Warming excess (400 TeraWatts)
• 100 years of heat burial would raise mean ocean temperatures by less than 0.25ºC.
• Organic CO2 burial would be considerable.

Practically

• A ‘slow-tech’ design would encompass low speeds and a 200-year life.
• Reinforced Concrete (RC) is used extensively as construction material, because of its cost, strength and durability.
• Building such machines would be viable for the existing offshore industry.
• The technology is easily transferable to less-developed countries.
• A low-maintenance design allows for minimal upkeep cost.

Environmentally

• The pump is enhancing ocean circulation which is threatened by Global Warming.
• The OHS is totally wave-powered using renewable energy.
• Huge amounts of CO2 are locked up by marine phytoplankton which flourish in the nutrient-rich water.
• Fish thrive. Couple that with Marine Park status and you have an oasis for fish revival.
• By locating the cold plume appropriately, local weather patterns are affected. Monsoons could be stabilised; Hurricanes averted.

Socially/ Politically

• The entire machine could be organised as a habitat. Island people would inhabit it, caring for the machinery and Marine Park as part of their lifestyle.
• Such projects could be financed by a Carbon Tax; ideally through a “World Carbon Bank”
• Governments could buy in to such schemes; it’s jobs for their industry and a way to be seen to be doing something!

Economically

• Development costs are estimated at €50 million
• A working prototype would cost approx €100 million
• India could subsequently build a full-size machine for €500 million.
• CO2 lock-up (marine cycle) is worth €20 million per annum
• Payback time for investors = 5 years (195 years profit)
• GW costs us some $500bn annually.
  Payback time for the Global Community = 7 months!!