Why most wind turbines have three blades instead of four and two?

Wind energy industry is rapidly growing. Together with solar energy they currently represent the two fastest growing renewable energy industries in the world. Wind turbines are located not just on land but also offshore and are becoming common sight in many countries of the world.

But what about wind turbine design in terms of number of blades? Did you ever wonder why most wind turbines have three blades instead of two or four?

If wind energy developers would to use two wind turbines instead of three, the turbine would be faster, and more speed in most cases results in increased energy output. However, using two wind turbines instead of three would make turbine far noisier and that would be serious downside, because some people even argue that turbines with three blades contribute to noise pollution let alone two.

And why not use four blades instead of three? Well, blades cost lot of money so using four blades instead of three would significantly add to overall costs of new wind energy projects.

In this sense, turbines with three blades are really the most balanced solution in three very important areas: efficiency, costs and noise. Future designs may come up with different solutions, not only in relation to the number of blades but also with the size and the location.

But for now, there are turbines with three blades that dominate the wind energy market.

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U.S. offshore wind energy sector - Feasible or not?

U.S. has significant offshore wind energy potential but federal government has so far done very little to ensure the development of this type of renewable energy. Wind energy projects onshore are booming in many U.S. states while offshore wind gets plenty of talk but very little action. In 2013, offshore wind produced just 162 kwh which is negligible amount compared to other renewables.

Many energy experts still argue whether offshore wind energy is feasible renewable energy option for United States. The recent study by the National Renewable Energy Laboratory and the University of Pittsburgh concluded that current technology and coastal wind patterns make offshore wind feasible.

However, in order to attract investors government needs to speed up a permitting process that now takes up to four years. The sector also requires policies that would provide incentives for construction of a technology because offshore wind energy projects currently have prices twice the cost of onshore projects.

The study found that the best locations for offshore wind energy projects are along the Atlantic coast between Boston and Washington, D.C., not just because of the region’s wind patterns but also because of heavy demand for electricity in the area. On the other hand, The Pacific coast’s deep water makes offshore wind energy development far more difficult.

The offshore wind energy projects that are underway are three federally funded offshore wind farms off the New Jersey, Virginia and Oregon coastlines that are expected to be built by 2017.

One thing is sure though. The prices of offshore wind will have to significantly decrease in order for offshore wind farms to compete with those onshore. In other words, short term speaking, the policymakers have to come up with significant incentives to attract investors. Offshore wind has the potential to become feasible, and in the end it all comes down to a price of electricity.

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Wind-gas combo - The right energy solution for Texas

Texas leads the nation in wind power generation, and currently has the installed wind power capacity of around 11,000 MW. It has been also reported that the state plans to add more than 6000 MW of new wind power capacity in the next couple of years.

However, the new electric generation in years to come will not come primarily from wind turbines in The Lone Star State but rather from natural gas, which is now thanks to the recent shale gas discoveries, cheaper than ever before.

The plenty of shale gas has been tapped in the last decade or so in Texas, and the shale gas is rapidly becoming the most important source of electricity, not just in the state, but on the federal level too.

Texas already leads the nation in natural gas production, and holds around 23 percent of the country's natural gas reserves. It has been estimated that the further 25 GW of new natural gas generation will be added within the next two decades. Three new natural gas power plants with the total capacity of 2250 MW should become operational in 2015.

Natural gas is not the perfect solution to tackle climate change because it emits harmful greenhouse gas emissions. The good news is that more natural gas will also mean less coal power plants. Coal power plants are the worst carbon emitters so replacing coal with natural gas is lot better than building new coal power plants.

Another good news is that the state will continue to invest heavily in new wind energy projects. Wind energy is much cleaner energy source than both natural gas and coal, so going for more wind energy is definitely good to tackle climate change and pollution.

In fact, wind-gas combo seems like the best solution for Texas, the one that could do the trick for many years to come. Wind is much cleaner energy source than natural gas but suffers from intermittency, and in this sense natural gas can cover for this lack of reliability of the wind.

Coal is still relatively cheap energy solution but this will all change if US Environmental Protection Agency (EPA) adopts new pollution control regulations. This will likely happen sooner than later, and Texas shouldn't have big problems in making the switch away from coal, after all there are plenty of both gas and wind in the state.

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