Blue Oil – harnessing the power of the sea

Hubbert's Peak

The world's energy supply and markets are beginning to change. There are signs that the peak global oil production has been reached, and that we could soon be on the downward slope to eventual depletion.

This phenomenon - known to industry analysts as Hubbert's Peak - has conventionally been expected in maybe twenty years' time. Some analysts though are saying the peak may come as soon as 2005-2007. It was in the 1950s that oil industry geophysicist M King Hubbert saw that oil production followed - after a certain time lag - a curve that closely resembled that of earlier oil discoveries, and used this to predict the peak in domestic American oil production that precipitated the 1970s energy crisis. Until it happened, no-one believed his theory. Now the only argument is when the global peak will occur. Not surprisingly, oil importing countries are taking the threat more seriously than exporting countries.

New oil discoveries have been in decline for some years now, and there are strong indications that Saudi Arabian fields - the world's largest - are at peak production, and members of OPEC (Organisation of Petroleum Exporting Countries) are struggling to increase annual production, especially of the more valuable “sweet crude”. This doesn't mean that we are about to run out of oil tomorrow, but it does mean we shall not be able to maintain current extraction rates, or regard oil as a cheap and abundant resource.

Meanwhile strong growth in energy demand, in China and India especially, means there will be increased competition for the oil that is produced. In short, prices are set to rise and not come down again. This year alone has seen prices rise from around $40 per barrel to nearly $60, with the prospect of $100 per barrel a very real possibility by the end of the year. With growing demand, approximately forty years reserves remain, which is not a long time to adapt to very different economic circumstances. Given the long list of industries that are dependent on abundant cheap oil, there is every incentive to think about what would be the best way to use what remains. As oil is a feedstock for plastics, chemicals, and pharmaceuticals, as well as a source of energy, some tough decisions will need to be taken. Some common uses for oil - such as powering personal mobility - may have to give way for more essential items. Alternative sources of electricity will be in particular demand in coming years.

Climate change

However, the prospect of burning the remaining trillion barrels of oil in known reserves adds to the threat from global climate change, and 60-80% reductions in carbon dioxide emissions will be required to stabilise atmospheric concentrations and avoid runaway climate changes, according to most climate scientists. This is a tough target requiring large-scale changes in the energy business.

Security climate

As the primary economic power source, oil is an important factor on the geopolitical stage. It is probably no coincidence that the major focus of Western military intervention is in an area with sizable reserves of oil and natural gas. Control of the reserves and the security of the many existing and proposed pipelines from the Caspian region seem to be major occupations of international players.

That the military presence in Afghanistan, Iraq, and Saudi Arabia is resented across the Islamic world is clear, and provides both a motivation and target for terrorist groups. Al Qaeda have specifically identified Western dependence on oil as an exploitable economic weapon, and insurgents in Asia and Africa have targeted oil and gas installations, presumably with this in mind.

On at least three major points, therefore, oil dependence can be seen as a threat by providing these vulnerabilities. Guernsey's oil dependency shows up in four major areas: electricity generation, food imports, air links, and personal vehicle dependence. Major upheavals in the oil supply would be felt in all these areas. All of the island's major economic sectors would be affected. Even President Bush has recently admitted that America’s dependence on imported oil is a national security threat, and is seeking greater energy efficiency and the development of indigenous renewables through technology.

Why ocean power?

Of the intermittent renewable energy sources, wave and tidal power are the most predictable and have the highest overall availability. That the resource is sufficient to provide the world’s electricity needs by developing approximately 0.1% of all available sites adds to the appeal of these technologies. The recent growth and success of wind power should be an indicator of what is possible, and the industry today is worth billions. As water is so much denser than air, its movement carries much greater energy, and generating plant can be much more powerful for a given size. Environmental impacts are generally very small, especially with offshore installations, and can even be positive with generating devices offering protection from coastal erosion to shorelines behind them.

Why Guernsey?

Guernsey has two large ocean resources available: the power of the waves on the west coast, and the tidal flows through the channels to the east. Technology exists now to tap either, and prudence would suggest that using a mixture of the two provides greater energy supply security over time. Given the presence of the Cable Link connection to the European grid, there is every prospect for an export market for clean, green electricity. Consumers throughout Europe are buying into green electricity supplies, and there are renewable supply obligations for distribution companies which must be met from somewhere. Often premium prices are paid.

Technology Review

Studies carried out in the early 1990s indicate that the available wave power in the English Channel is of the order of 50 to 60 kilowatts per metre of wave front. With the added bonus of tidal streams reaching 7 knots on occasion, Guernsey is well placed for ocean-based power. The number of companies operating or researching in the field is growing, and some of the most exciting ideas and products are examined below.

Pelamis - an exciting new approach to wave power that allows offshore operation, and that is unaffected by tidal range, the ‘Pelamis’ system made by Ocean Power Delivery Ltd, resembles a floating sea-snake made up of a number of segments. Hydraulic couplings between each segment allow the device to capture energy and convert it to electricity for transmission on shore. It has been estimated that Pelamis can harvest approximately 30 Megawatts of power in a single square kilometre of sea surface. The novel design promises to be much more robust than earlier approaches to wave power, as it operates "nose on" into the waves rather than as a "broadside" collector. There is currently a 2.25MW installation in operation off the coast of Portugal, which has cost approximately €8 million to install. With the experience of these large-scale tests, it seems likely that final installation costs will be lower.

Blue Energy tide mill - developed by a Canadian company, this is a novel vertical-axis mill, which means the electricity generating equipment remains raised out of the water for easier maintenance and access. With the mills built into large-scale concrete housings, Blue Energy have been pioneering an extra layer of infrastructure development into their projects, as a tidal "fence" of linked units can act as the support for road (and presumably railway) links across bays, or between islands, generating electricity all the time as the tide flows beneath. With capital costs of US$1200-3000 per kW installed, and a generating cost of approximately 4 cents US per kilowatt-hour after six years, Blue Energy have a strong claim to being competitive in most energy markets.

Independent Natural Resources, Inc – The “Seadog” wave pump uses the vertical motion of waves to drive a piston pump that can pressurise seawater for electricity generation. As with the Pelamis, this is an off-shore technology, so can be sited away from the coast. The manufacturers claim that from a distance the buoys are no more visually intrusive than a small fleet of fishing boats. Also in common with Pelamis, being an offshore installation, the buoys are less environmentally intrusive than shore-mounted devices.

Many other wave and tidal power devices are either available now, in prototype, or in research, and many of the grid connection difficulties are addressed by more sophisticated, computerised control mechanisms which have become available in recent years. It is a rapidly moving field with increasing investment, from both private and public funds. Guernsey’s location, and growing need for a new export sector, points the way towards ocean-derived power.

In the years ahead, the seas around the islands could become a valuable source of “blue oil” – clean and inexhaustible energy for the markets of tomorrow. To bring this resource on line is maybe the largest single contribution the Bailiwick could make towards tackling global climate change and securing the energy future.

Mike Johnson, B.Sc.(Hons), Dip.Env.Pol. (Open)

Home