Offshore Renewable Energy: An Overlooked U.S. Resource?

Abstract:In Europe, ocean winds, waves, and tides will be tapped increasingly to generate electric power, while in the U.S., such forces seem to get short shrift from those closest to them—offshore oil and gas companies.

Analysis:Offshore wind, waves, and tidal variances are going to be increasingly significant contributors to power generation during the next five years, particularly in Western Europe, says a new study released this past week.

Why significant? Because the future promises an increasing global demand for energy set against a long-term trend of depleting conventional energy resources (make that oil and gas). Natural renewable energy sources like solar heat; geothermal steam, and river rapids already are in use around the world. More sophisticated power sources like fuels cells are just getting a start. And then, there's methanol generated from corn, as well as other so-called "biofuels" like the methane generated in landfills by microbial decomposition of garbage. But ocean power, using the world's winds and the seas' tides and currents, is only now getting serious commercial consideration.

Basically, offshore renewable energy (ORE) involves harnessing wind and wave/tidal forces to generate electricity. In the first instance strong, steady winds turn offshore-based, bladed turbines that are hooked up to power generators, with the resulting electricity transported to shore via high-voltage electrical cable. In its crudest form—from the big windmills of Holland to the smaller mill-driven water pumps of farm and ranch country—the wind is one of the oldest power sources in recorded history.

But generators also can be activated by the frequency of ocean waves, with the turbine placed either on or below the water's surface. Tidal movement can be harnessed, too. When the tidal cycle arrives at and departs from shore, the surge can pass though impellers that turn generators. This can take place at beaches, in river deltas and estuaries, and even on offshore platforms. Combined, these common marine phenomena form the basis of ORE.

According to Douglas-Westwood Ltd. (D-W), a widely respected U.K. energy analysis consultancy, ORE is expected to become a US$1 billion annual world market by 2007. Meanwhile, more than US$4.5 billion in capital expenditures will be made between 2002 and 2007 to build ORE installations, with more than 90 percent of that spending taking place in Western Europe. Of that, approximately 97 percent will go for offshore wind power, with only about 3 percent aimed at waves, and the tiny remainder at tides/currents.

Although the report is impressive in its detailed analysis of ORE potential in Europe, its most deafening aspect is the almost total silence in the form of contributions made by the U.S. of A. That's because in this country, virtually no contributions have been made to ORE thus far, and any existing plans seem to be vague and not likely to bear fruit until far beyond 2007.

Oh, there is a growing trend toward renewable energy use in the U.S. That trend is dominated, however, by onshore wind power—you know, the clusters of three-bladed propellers atop high, white towers that you see on TV and in movies, the most famous of which are located near Palm Springs, CA. However, little if any attention is being focused in this country on offshore wind or wave and tidal/current power.

But back to the D-W analysis. Called "The World Offshore Renewable Energy Report," it was commissioned by Renewables UK, a business support unit of the U.K. Dept. of Trade & Industry. The lead author is D-W's Will Rowley, who says ORE activity is set to grow at a remarkable pace in Europe.

"In the past 18 months the number of future ORE projects identified on our database has leapt from 20 to more than 114, with 61 scheduled for installation in the period to 2007," he said. He added that across the sectors there is a tremendous range of business opportunities including 822 miles (1,326 km) of subsea high-voltage cable and more than 1,100 turbines and foundations, as well as survey, installation, and related contracts.

Rowley forecasts that the offshore wind market alone will climb from US$251 million in 2002 to US$946 million in 2007, a growth of more than 276 percent. Yet, he regards the figures as conservative, since they represent less than 40 percent of the total $11.6 billion that developers say will be spent on offshore wind projects to 2007.

The D-W researcher notes that recent environmental and related legislation, enacted in an effort to reduce the impact of energy production on climate change, has led to a dramatic rise in ORE use. He also points out, however, that in small countries like the U.K., the economically and environmentally acceptable onshore sites are being developed rapidly, and as the pressures to produce increased levels of renewable energy intensify, governments and developers are looking to the offshore environment as the logical expansion point. The same is true in other European countries with offshore access, since none can be considered "big," particularly if compared to coastal states or provinces in the U.S. or Canada.

However, in the U.K., 16 wind, five wave, and four tidal projects are being considered between now and 2007. In Germany, 19 wind projects fit in that category. Norway also plans a number of wind and wave projects. France, Spain, and Portugal, as well as Italy, also are readying ORE projects of all varieties.

Here with the Wind

The study expects 165 mw of wind power-generating capacity to be installed offshore this year, followed by a dramatic growth curve that will have annual installations exceeding 900 mw by 2007. Europe will capture 92 percent of capital expenditures, with the remaining 8 percent going to North America.

Oddly enough, Denmark is leading the 2002 offshore wind power market with a forecast of 300 mw during the period 2001 to 2003. But according to Rowley, removal of government subsidies has brought future offshore wind project proposals to a halt.

"The U.K. is now the next major growth market," says Rowley, "and we expect it to account for 42 percent of generating capacity installed in 2004. Over the complete 2002 to 2007 period, the U.K. is likely to install 907 mw, which is 21 percent of total new capacity. Germany will follow in 2005 with a program totaling 1,295 mw, giving it the largest share (37 percent) of the market for that year.

In 2005, however, the study expects North America to enter the ORE market, first with a wind project in U.S. waters (off either Massachusetts or New York), followed in 2007 by 317 mw being installed off Eastern Canada.

The Tide Rushes In—Sort Of

Although it is widely recognized that the tidal cycle is one of the greatest untapped energy sources on the planet, engineers have been trying for hundreds of years to harness it, with little result.

Generally, such systems require a tidal range of more than 23 ft (7 m), and most potential development sites are poorly located in relation to potential users and usually are smack dab in the middle of areas with high ecological value.

However, despite the success of a 240-mw tidal barrage power plant in the estuary of the Rance River in Brittany, where tidal ranges are indeed dramatic, there are concerns—mostly environmental—that have turned the eyes of potential tidal power developers toward tide-generated coastal currents a bit farther offshore—using tidal fences and turbines, says Rowley.

The D-W report estimates that world tidal power expenditures will approach only about US$22 million by 2007.

Catching the Waves—An Elusive Exercise

Wave energy is now used routinely to power navigation buoys throughout the world; however, due to accessibility and grid connection cost problems, the predominant form of wave energy devices are those that are placed along the shoreline, rather than near the shore or far offshore.

The U.K. and Japan have led development of wave energy devices and account for more than 60 percent of worldwide development spending. More than 250 differing wave power devices have been designed and/or deployed, says Rowley, but no one device has yet reached universal acceptance or widespread use. Even currently funded offshore wave projects will average total capacity of only 1 mw, with the largest being 2 mw.

In the end, wave power during the survey period can best be described as a pre-commercial phase in the overall ORE development cycle, with D-W forecasting 2002 total capital spending of only US$12.7 million, increasing to somewhat more than $US47.4 million by 2005.

So, there it is. For ORE development, European nations and Japan will be the ones to watch for new ORE technology and increasing numbers of generation plants.

The U.S., Where the Shrift Is Short

In the U.S., there is some interest, albeit minor in comparison. However, it seems a bit half-hearted, given that U.S.—and to a point, Canadian—oil and gas companies have nearly 75 years' experience operating in the offshore environment—the one that the Europeans and Japanese are tapping for ORE.

There are a few tests going on in the U.S. Small wind- and wave-driven generators have been installed on Gulf of Mexico platforms, the power generated being used for emergency or auxiliary functions. And the aging platforms located in Alaska's Upper Cook Inlet near Anchorage are the subject of a possible wind and tidal energy initiative, once the oil reserves run out for most of them in the next few years. But the companies that operate the platforms apparently are interested mainly in handing them over to state or federal governments for such uses, saving on the cost of removing the platforms altogether.

So, while U.S. government and industry are working frantically to discover more oil and gas around the world, and are advancing on new recovery technology for existing U.S. fields, as well as on some day developing oil shale and gas hydrates, their interest in and focus on offshore wind, waves, and tides is token, at best.

Could this be still another opportunity for companies who can use the knowledge of their core industry—finding offshore oil and gas—to develop technology for still another energy source, based on the oceans' winds, waves, and tides? It's a thought, at least.

(For more information on the Douglas-Westwood report, click here.)