Star Phoenix Base

By David L. Brown

Of the various renewable energy options that have been considered in recent decades, such as solar and wind power, one that has made the least progress has been wave energy. I remember in 1971 leafing through a magazine in Germany that featured an illustrated article about the idea of turning the kinetic power of ocean waves into electricity.

Now at last, that idea may be about to take off. An article in the June 10-16 issue of The Economist describes the first stages of what is to become the world’s first “wave-power farm” on the coast of Portugal. Here’s a sampling from the article, entitled “Making Waves”:

… Near Póvoa de Varzim, off the northern coast of Portugal, three 150-metre-long articulated snake-like pontoons, called Pelamis Wave Energy Converters, are in the final stages of being hooked up to the country’s national grid, says Andrew Scott of Ocean Power Delivery, the firm behind them. Each one has three power-converter modules distributed along its length, which transform the flexing motion at the snake’s joints into electricity as the snakes are buffeted by the waves. The three snakes are the first stage of a planned 24-megawatt wave-power farm, which will be capable of providing 15,000 households with power. The Pelamis’s design avoids the trade-off between resilience and efficiency by switching to a higher-efficiency mode in calm seas.

According to the Economist article (read it here, subscription requred), a new and more efficient design lies behind this program, providing up to ten times the output of earlier designs which proved too expensive to build and operate.

Wave power is another “green” option that could go far toward reducing humanity’s dependence upon non-renewable and polluting energy sources. According to an estimate from the U.S. Dept.of Energy’s National Renewable Energy Laboratory, wave power on America’s East Coast could provide 10 to 25 times more electricity than the entire wind power potential of the Midwest. That’s quite a statement, and offers hope that we can begin to tap another source of clean and renewable energy in the near future.

Unlike the ethanol mania that is currently sweeping the land — promoting an inefficient, non-sustainable process whose main purpose seems to be to transfer money from the pockets of taxpayers and consumers into those of farmers, agri-businesses and investors in ethanol plants — wave power, like solar and wind, could make an important contribution toward building sustainable energy for the future.

By David L. Brown
Earlier today we wrote in Star Phoenix Base about the growing development of wind power, and noted the need for new technologies to make the conversion of “free” wind energy into electricity. In a recent issue of The Economist, just such a development was reported. Here’s the lede:

Energy technology: Wind turbines that rotate about a vertical axis, rather than the usual horizontal one, could have a number of benefits

Wind turbines are springing up in all sorts of places around the world, from China to California, but most of them have the same basic design: the blades rotate about a horizontal axis, as in an old-fashioned windmill. Such turbines can generate electricity at a cost not much higher than non-renewable, fossil-fuel sources—provided the wind is blowing, that is. But if proponents of a rival design are to be believed, electricity can be generated from wind even more cheaply, using turbines that rotate about a vertical axis, like a playground roundabout.

TMA, a company based in Cheyenne, Wyoming, announced in November that its first vertical-axis wind turbine (VAWT) would soon be ready for commercial production. The TMA system has two sets of vertical blades. The two inner blades, each shaped like a half-cylinder, catch the wind and rotate about a central axis, while the three outer blades, shaped like aircraft wings, are fixed. The interaction between the two sets of blades causes a drop in pressure in front of the rotating blades’ leading edges, which further increases the rate of rotation. TMA claims that its system harvests 43-45% of the wind’s available energy; conventional propeller-style turbines, in contrast, have efficiencies of 25-40%. Read the whole story; subscription required.

The TMA website describes the benefits of the company’s designs, stating:

The TMA turbine offers substantial advantages over conventional propeller-style wind turbines such as functionality, ease of maintenance and operation, lack of electronic interference, no ground resonance, a more acceptable profile, quieter in operation, and NO BIRD or BAT KILLS. Various TMA turbines have been in operation for over 8 years without causing any avian mortalities.

As we reported earlier today, one objection raised to a planned wind farm on the Texas Gulf Coast is the danger to migrating birds. If TMA’s claims are accurate and their wind turbine designs are completely safe for flying birds and bats, this represents a major advantage that will endear TMA’s products to environmentalists. The improved efficiency in converting wind to electrical power is a big plus for everyone, from power companies to consumers. Star Phoenix Base will keep an eye on TMA and keep you informed of developments.