Wind farms are springing up all across West Texas, and in other parts of the US. Is this trend on that will last? What should be done when the wind stops blowing? Or if subsidies run out?
see also: Renewable and alternative energy , Clean-tech and environmentally conscious investing , energy industry , Environment issues , solar energy , wind energy ,hydroelectric power , wind energy in Brazil
Table of Contents:
Wind Maps:
In the US: according to the PickensPlan; "Studies from around the world show that the Great Plains States are home to the greatest wind energy potential in the world — by far. The Department of Energy reports that 20% of America's electricity can come from wind. North Dakota alone has the potential to provide power for more than a quarter of the country."
Wind power currently accounts for 48 billion kWh of electricity a year in the United States — enough to serve more than 4.5 million households. That is still only about 1% of current demand, but the potential of wind is much greater.
A 2005 Stanford University study found that there is enough wind power worldwide to satisfy global demand 7 times over — even if only 20% of wind power could be captured. Building wind facilities in the corridor that stretches from the Texas panhandle to North Dakota could produce 20% of the electricity for the United States at a cost of $1 trillion. It would take another $200 billion to build the capacity to transmit that energy to cities and towns. That's a lot of money, but it's a one-time cost. And compared to the $700 billion we spend on foreign oil every year, it's a bargain. source: PickensPlan
WINDS sweeping across New England, in the north-east of the United States, blow at an average of about 4 metres per second (m/s). But a few hundred metres offshore they blow more than twice as fast. This increase in speed is found offshore in much of the world. But although engineers know how to build turbines to turn offshore wind into electricity, they can do that only in waters up to about 40 metres deep. Wind-turbine towers are pounded deep into the seabed, or anchored in massive blocks of sunken concrete.
Now wind power could be taken into deeper waters. Building offshore wind farms is expensive: a turbine can cost at least 50% more than one built on land. But the stronger winds out at sea can generate more revenue: a wind of 10m/s can produce five times as much electricity as wind blowing half as fast, and this greatly favours building more offshore wind farms, says Walter Musial, a senior engineer at the National Wind Technology Centre, a government research lab in Boulder, Colorado. Yet just 300 to 400 offshore wind turbines have been built worldwide, most of them in British or Danish waters. None have been built in America. The main reason why there are so few is that people think they ruin the view and spoil the immediate offshore area.
Given the gigantic distances in America especially, remote generators require miles of nuts-and-bolts infrastructure to get the power to population centres. Transmission is expensive and often an afterthought, at least for consumers. Even within windy areas the generators are often scattered across wide expanses, which makes gathering it and bringing it to market difficult. Rob Gramlich of the American Wind Energy Association calls transmission the industry’s “biggest long-term barrier”.
Putting transmission underground, through a dense suburban area like Boston’s, can cost up to $20m per mile.
In Texas, $3-6 billion more is needed for transmission, according to a recent filing by ERCOT, the Texas electrical grid operator. Overall, across America, between $12-15 billion per year is being spent on transmission infrastructure, according to Lawrence Makovich of Cambridge Energy Research Associates. Costs are worsening with the rocketing prices of steel, copper and engineering services.
All of which raises the pesky question of who pays. One way or another it is generally the users, who naturally resent the extra charges. But being fair to everyone is complicated. A transmission system is a network; when you connect a new line to an existing system, it affects power flows throughout. The actual costs can be hard to predict. The electricity industry’s answer is “socialisation”—the cost of any new capacity is spread evenly among a state’s consumers. This can be an effective quick fix, but it risks burying price signals and creating some thorny interstate issues.
read more from the economist.com
A grandiose plan to link Europe's electricity grids may recast wind power from its current role as a walk-on extra to being the star of the show
The question of whether the world would be powered by direct current (DC), in which electrons flow in one direction around a circuit, or by alternating current (AC), in which they jiggle back and forth, was decided in the 1880s. Thomas Edison backed DC. George Westinghouse backed AC. Westinghouse won.
The reason was that over the short distances spanned by early power grids, AC transmission suffers lower losses than DC. It thus became the industry standard. Some people, however, question that standard because over long distances high-voltage DC lines suffer lower losses than AC. Not only does that make them better in their own right, but employing them would allow electricity grids to be restructured in ways that would make wind power more attractive. That would reduce the need for new conventional (and polluting) power stations.
Wind power has two problems. You don't always get it where you want it and you don't always get it when you want it. According to Jürgen Schmid, the head of ISET, an alternative-energy institute at the University of Kassel, in Germany, continent-wide power distribution systems in a place like Europe would deal with both of these points.
The question of where the wind is blowing would no longer matter because it is almost always blowing somewhere. If it were windy in Spain but not in Ireland, current would flow in one direction. On a blustery day in the Emerald Isle it would flow in the other.
Dealing with when the wind blows is a subtler issue. In this context, an important part of Dr Schmid's continental grid is the branch to Norway. It is not that Norway is a huge consumer. Rather, the country is well supplied with hydroelectric plants. These are one of the few ways (but not the only way, see article) that energy from transient sources like the wind can be stored in grid-filling quantities. The power is used to pump water up into the reservoirs that feed the hydroelectric turbines. That way it is on tap when needed. The capacity of Norway's reservoirs is so large, according to Dr Schmid, that should the wind drop all over Europe—which does happen on rare occasions—the hydro plants could spring into action and fill in the gap for up to four weeks.
Put like this, a Europe-wide grid seems an obvious idea. That it has not yet been built is because AC power lines would lose too much power over such large distances. Hence the renewed interest in DC.
Westinghouse won the battle of the currents in the 1880s because it is easier to transform the voltage of an AC current than of a DC current. High voltage is the best way to transmit power (the higher the voltage, the smaller the loss), but high voltage is not usually what the user wants. Power is therefore transmitted along high-tension AC lines and then “stepped down” to usable voltages in local sub-stations.
Edison was right, however, to argue that DC is the best way to transmit electricity of any given voltage. That is because the shifting current of AC runs to earth more easily than DC does. To avoid this earthing, AC lines have to be built a long way from the ground—and the higher the voltage, the farther away they need to be. At 400 kilovolts, a standard value for long-distance transmission, an alternating current 30 metres (100 feet) from the ground has a fortieth of the loss of a similar cable at ground level. But even at this height an overhead DC line will beat an AC line at distances more than 1,000km (600 miles), while ground-level DC will beat AC at distances as short as 30km.
Dr Schmid calculates that a DC grid of the sort he envisages would allow wind to supply at least 30% of the power needed in Europe. Moreover, it could do so reliably—and that means wind power could be used for what is known in the jargon as base-load power supply.
Base-load power is the minimum required to keep things ticking over—the demands of three o'clock in the morning, or thereabouts. At the moment, this is supplied by traditional power stations. These either burn fossil fuel and thus contribute to global warming, or use uranium, which brings problems such as how to get rid of the waste, as well as political opposition.
Though wind power has its opponents, too, its environmental virtues might be enough to swing things in its favour if it were also reliable. Indeed, a group of Norwegian companies have already started building high-voltage DC lines between Scandinavia, the Netherlands and Germany, though these are intended as much to sell the country's power as to accumulate other people's. And Airtricity—an Irish wind-power company—plans even more of them. It proposes what it calls a Supergrid. This would link offshore wind farms in the Atlantic ocean and the Irish, North and Baltic seas with customers throughout northern Europe.
Airtricity reckons that the first stage of this project, a 2,000 turbine-strong farm in the North Sea, would cost about €2 billion ($2.7 billion). That farm would generate 10 gigawatts. An equivalent amount of coal-fired capacity would cost around $2.3 billion so, adding in the environmental benefits, the project seems worth examining. Such offshore farms certainly work. Airtricity already operates one in the Atlantic, and though it currently has a capacity of only 25 megawatts, increasing that merely means adding more turbines.
Nor is this the limit of some people's vision. The Global Energy Network Institute, based in San Diego, California, reckons high-voltage DC lines could be used to bring solar energy to market from places such as the Sahara. Wind and geothermal power could be gathered from as far afield as South America and Siberia. Such a globalised market has its attractions. Whether the world is ready for the Organisation of Electricity Exporting Countries to take over from OPEC, though, remains to be seen.
Marquiss Wind Power raises $1.3M for roof-top turbines
Knight & Carver Wind Group Inc., a National City, Calif.-based repairer and manufacturer of wind turbine blades, has raised $12 million in private equity from Global Environment Fund. Get more info