hydro kinetic wave

A Carbon-Neutral Energy Plan for the United Kingdom: Wave Power

In February, prior to the COVID-19 outbreak, London-based architect and author Nathan Silver submitted a remarkably detailed plan to convert the United Kingdom to carbon neutral energy production. He wrote to Dominic Cummings, a chief advisor to Prime Minister Boris Johnson. Here is Silver’s letter to Cummings, which the author has kindly shared with Common Edge:

Dear Mr Cummings, 

What follows is my suggestion of a national plan to achieve carbon-neutral generation of usable energy in the shortest possible time, at the lowest comparable cost, using the available resources and the skilled workforce that we have. With this plan, the supplementary need for combustion energy or nuclear energy sources would be minimal, diminishing to none. Once it is begun, I believe complete carbon neutrality for the UK could be achieved in only ten to twelve years. 

What this will require is resolve, leadership, and the creation of a government agency with high engineering capabilities and consolidated planning, administrative, and expenditure powers. As a considerable added benefit, the outcome of the plan and its working particulars would have high export value. Moreover, news about its initiation might well provide the vital basis and inspiration to others for COP26 in November in Glasgow. 

The means of achieving all of this is wave power: harnessing the forces of wind and gravity in new offshore energy farms. 

My own interest in wave power began in 1972, when, as Chief Designer of the Brighton Marina, I studied wave forces in specially built tanks to develop the marina’s uniquely designed harbor walls and breakwater built out into the English Channel. What that led me to understand is that generating electrical energy from offshore wave power should be easier, quicker and cheaper to achieve than with offshore wind power. (The absence of wave power from the currently most popular range of alternative energy modes is something I’ll shortly try to explain.) 

COMPARING COSTS FOR FORMS OF CARBON-NEUTRAL ENERGY 

To achieve non-carbon electrical generation, the main schemes that we now reckon to be the most feasible are these: 

Solar power. A great resource, even in the UK as the costs of photovoltaic glass continue to drop, but of relatively low efficiency for us compared to installations in lower latitude climates and regions with less cloud cover. In the UK, main dependence on solar power would require a considerable energy backup of fossil fuel and/or nuclear power, and a substantial amount of economically feasible energy storage. 

Land-based wind power. An excellent resource for the UK, but the downside includes the high cost of land, relatively high construction costs, bird hazard, NIMBY opposition on the grounds of visual and operational intrusions into prevailing landscapes, and the backup requirement of considerable fossil or nuclear energy, as well as energy storage. 

Offshore wind power. Likewise an excellent resource for coastal countries. The downside includes very high construction and maintenance costs, the upkeep and policing of considerable non-fishing and trawling zones, high costs of undersea power transmission, moderate alternative power backup requirements, and the relatively high costs of onshore cabling distribution from coastal landings. The very high construction costs of offshore wind power occur because of the need to build ocean anchorages for tall cantilevered structural masts—in the highest current sizes, 164 m to the hub and 230 m to the revolving blade tip—which are subject to the shear stress, buckling and torsion forces of severe wind storms. The underwater anchorages for the masts, which must resist overturning, are also costly installations. Maintenance costs are likewise multiplied, not only because of sea access and dangers, but on account of the need for sporadic unplanned structural attendance. 

Offshore wave power. This is the highly feasible and productive alternative that has remained pending, up to now. Cabling distribution costs are similar to that for offshore wind power, but there are no outsized material commitments and structural costs for constructing and anchoring towering masts supporting heavy generators. More compact sea-level hydrokinetic energy structures would need mostly to sustain the difference between gravity and buoyancy. Industrial fabrication and marine installation could be done much more rapidly, at far lower costs than for offshore wind power. 

In physical principle, hydrokinetic energy is the sovereign natural power. Unlike sun and wind, wave energy is virtually uninterruptible. Seas churn with waves moving in all directions, and the sea surface is continually rising and falling—the painted-ocean calm of Coleridge’s description never actually occurs. Up to a point, human exploitation has followed. As Blaise Pascal investigated and described in the 17th century, water as an incompressible fluid transfers pressure undiminished. Hydraulic rams and hydraulic lifts were developed to work on this principle. Water’s density has provided the means of flotation for ships since prehistoric times; its density also lowers the net weight of immersed objects, which is greatly advantageous for the economical support of engineered structures. 

A cubic meter of water weighs nearly 1000 kg, while the weight of a cubic meter of air near sea level averages about 1.28 kg. Water’s weight of about 784 times greater than air is why a walker can easily withstand a 50 mph wind, but a swimmer can be knocked over by a 3 mph wave. Wave power is calculated to have a “power density” of about 25 kW/m2, compared to about 1 kW/m2 for photovoltiac glass at solar peak, and 1 kW/m2 for wind at 12 m/second. So while solar power and wind power have conversion efficiencies usually no higher than 15%, the applied forces of wave power—as Pascal’s Law suggests—are capable of converting more than 50% of received energy. The big difference means that, with well engineered hydrokinetic conversion, the motion of water that could be harnessed in an area of ocean only 10 miles x 10 miles “could fully power California,” as the chief engineer of a US Pacific coast wave power developer has calculated. The much smaller footprints of wave power farms would also of course interfere far less with fishing and trawling, and comparatively, would be much easier to maintain, patrol, and defend. 

SO WHY HAS WAVE POWER GOTTEN NOWHERE? 

As with the cautionary historical developments of combustion engines, flying machines, and rival vision and music recording methods, when initial technical designs begin to find economic success they are likely to be adopted as the standard ways to go, which subtly, and often overtly, deters alternatives. The achievement of nuclear power deterred interest in alternative carbon-neutral power for a long time, despite nuclear power’s huge costs and safety problems. The development and realization of offshore wind power has likewise impeded the development of hydrokinetic power. 

Moreover, compared to wind power, the kinetic forces in oceans that can be harnessed are complicated: oceans move in heaving rises and falls, in wave rolls, with directional waves, non directional choppy movements, current flows, and strong but periodically reversing tidal movements. With so many possible ways to go, innovative research, wave tank testing and ocean tests at increasing scales are costly though vital propositions. The result to date of wave power’s multiple design possibilities and engineering directions has been net uncertainty, with numerous inventions proposed by free market startup entrepreneurs that favor difference from others in order to be patentable. The competitive confusion of hydrokinetic energy’s diverse, largely underfunded, approaches to achieve commercially exploitable originality, in the absence of any overseeing and commanding stakeholder, has disastrously impeded development of power converters that have to demonstrate efficiency, robustness and reliability. 

For free market wave power developers, a second great problem is the approvals mishmash of requiring international agreements for some of the more valuable ocean sites, securing confirmation on minimum interference with fishing, providing evidence of no significant environmental effects on oceanographic, geophysical and biological conditions, and the attainment of government planning permissions. When energy developers have to petition the authorities rather than be the authorities, the disincentives have looked vast, expensive, and likely to take forever. 

THE ENGINEERING CHALLENGE 

The effective hydrokinetic exploitation that I am advocating will almost certainly require researching, designing, and commissioning several different specialized designs: for the inlets of the UK’s very suitable tidal basins, designed water velocity converters; for regions with shallow sea floors, designed wave surge converters; for deep waters, designed buoyant floats or gravity compression converters. On a map, the plan of a typical offshore wave power farm might appear as a consolidated area covered by large circles, each circle probably made up of concentric rings of wave power machines mechanically connected to the central hub of the large ring, where above sea level—for economical maintenance—there would be a small generator plant converting the mechanical drives to electrical power, which would run via submarine cabling from each ring hub to a consolidated hub and, thereafter, to the shore. It may be hard to pick a set of ocean technology winners, but the vast quantities of energy potentially available suggests that perfected winners will indeed emerge. 

The possibility of over 50% efficient conversion of energy in hydrokinetic power is mentioned in textbooks, but we are still not close to attaining that. The key technology achievements for the UK’s hydrokinetic engineering team would need to be the improvement of the interfaces that mechanically link the huge-force-but-normally-slow-movement of the rolling sea, into far less forceful but very high speed mechanical energy. That is the sort of conversion that occurs between a Swiss watch’s mainspring and the second hand, the turbine effect that produces the rapid whizz and air blast of Dyson hand dryers, or—perhaps the most appropriate analogy—the effect of James Watt’s 1776 improvement of the steam engine that was the enabling development for the Industrial Revolution. 

WAVE ENERGY’S MANHATTAN PROJECT/TENNESSEE VALLEY AUTH0RITY/EAST INDIA COMPANY 

Perfecting various means to efficiently convert hydrokinetic power into turbine movement is the central issue to resolve for making wave power-derived electricity become not just feasible, but very cheap. In engineering terms it requires the solution of a quite simple bunch of problems, but it would need a crash program to get it done effectively and quickly. Achieving that would be a far easier job than electrifying the American south in the 1930s as accomplished by FDR’s Tennessee Valley Authority, or organizing the nuclear physics teamwork’s Manhattan Project for the atom bomb. There is no question that an expert working task force could do the job. 

The ultimate benefit is that, once perfected, the engineering designs, or the entire working administration, could be licensed to other countries (cheaply, I suggest), for adoption in the eastern Atlantic, off South Africa, in the Pacific north of California and west of Australia, the Sea of Japan, the South China Sea, along remote islands, and offshore from every arid coast that needs to desalinate sea water. The teamwork required might end up, in a way, more closely resembling the international development and trading accomplishments of Britain’s own East India Company (minus its shameful imperialism). 

MOBILIZATION  

In sum: I am advocating the immediate creation of a UK Wave Power Authority, to be given full government financial, administrative, and international-legal support; to be tasked with achieving research and testing, and leading to the full replacement of the UK’s carbon-based power generation in the shortest possible time. For maximum efficiency and rapidity the Authority should have two heads, as the Manhattan Project did: a chief engineer (akin to Robert Oppenheimer), and an administrator in close support (akin to General Leslie Groves). The development team should consist of mechanical engineers, hydrokinetic experts, and industrial designers recruited worldwide. The Authority will also need a mapping and landscape-architectural team to identify and plan suitable onshore sites for reservoirs to hold off-peak pumped water for electricity generating discharge during peak power periods. And the Authority needs an industrial mobilization team, whose vital job would be identifying, contracting, and if necessary requisitioning steel, alloy, and other materials, shipbuilding yards, and construction and supply vessels, as well as assembling associated labour forces and instituting manpower and womanpower specialist training. 

Changing national power sources to become entirely non-carbon in the shortest possible time would require the parallel withdrawal of carbon energy. The most equitable and productive way to do that, I suggest, would be to give the going-out-of-business carbon energy companies negotiated tendering privileges for wave power material supplies, construction work and ship support (but to prudently keep the future energy outcome as a broadly enriching national resource, as Norway did with its North Sea oil and gas, not as an ongoing further reward to the energy companies). The logic of adopting wave power as the main carbon-neutral energy source also means that the “security of supply” claimed uniquely for nuclear power, with its high preparatory and very high negotiated supply costs, would no longer be relevant. Fortunately (and unsurprisingly), the latest round of nuclear power stations have not yet got very far. Hinkley Point C will not be built in time, will not ease a capacity crunch, and if somehow completed, would condemn national energy to skyhigh costs for decades when all other carbon-neutral energy costs are falling. Existing contracts for Hinkley Point C and the provisional agreements for any more nuclear power plants should be terminated, with abortive penalty charges paid and contractors reimbursed, or offered compensating negotiated contracts for wave power work. With wave power mobilization at its most efficient, its modules should be capable of being built very quickly and with far less danger to health at many old and new industrial sites, like the Spitfires and tanks of World War II. So that is the outline of my proposal. I would be delighted to discuss it further with you, Mr Cummings, or with others in government who are prepared to consider proceeding with a national wave power plan.

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