It has become clear to almost everyone that the production of electricity using fossil fuels is unsustainable, hence the race to develop renewable sources of energy such as wind energy. Wind-powered turbines are the largest renewable energy source across the world.
What is wind energy, why is it the largest renewable energy source globally, which country produces the most wind energy, and what is the connection between wind turbines and slip rings? We answer all these questions and more in this article.
What is wind energy?
Wind energy, sometimes known as wind power, is electrical power generated when the blades connected to a turbine use the wind’s kinetic energy to spin a rotor. When engineers place the blades, they ensure that the blades are in the way of the wind. Thus, the wind moves them as it attempts to pass.
Even though it may not be apparent, wind energy is connected to solar energy. The website focused on conserving energy, Conserve-energy-future.com, explains this connection. It says, “The wind is caused by uneven heating of the earth’s surface by the sun.” Adding that when it’s heated, “Hot air rises up and cool air flows in to take its place.”
Regarding the generation of electrical power from wind energy, the U.S. Energy Information Administration (EIA) explains that the “Wind flows over the blades creating lift (similar to the effect on airplane wings), which causes the blades to turn.” Adding that “The blades are connected to a drive shaft that turns an electric generator, which produces (generates) electricity.”
1. The history of wind energy
The use of the wind to generate energy dates back thousands of years. For instance, the EIA says that people used wind energy to propel boats as early as 5,000 BC.
The EIA also reports that “By 200 BC, simple wind-powered water pumps were used in China, and windmills with woven-reed blades were grinding grain in Persia and the Middle East.” Over the centuries, wind energy would remain an important power source for pumping water from underground lakes, grinding grain, and cutting wood in sawmills.
Even though the use of wind pumps and turbines declined as electrical power became available to more people in the 1930s, wind energy would see a rebound in the 1970s. According to the EIA, this resulted from the oil shortages experienced during this time, which forced governments to invest in other forms of energy.
Growing consciousness about the adverse environmental effects associated with the use of fossil fuels in the 21st century has prompted almost every government on the planet to start supporting efforts to move away from burning fossil fuels to generate electricity. This has led to a proliferation of wind farms both inland and offshore.
2. Soaring wind turbine sizes
Central to the generation of electrical power from the wind are wind turbines. Each turbine can have as many as 8,000 parts, and slip rings are some of the most critical components.
When you look at an image of a wind turbine, it’s hard to understand how big these machines are. Energy.gov provides an idea of how tall these structures are: “Wind turbine blades average almost 200 feet [61 meters] long, and turbine towers average 295 feet [90 meters] tall—about the height of the Statue of Liberty.”
Even though today’s wind turbines are already massive, it looks like we haven’t seen the biggest yet. Chris Baraniuk writes for BBC.com and explains why giant turbines are pushing the limits of possibility.
Baraniuk reports that “Wind turbines just keep getting bigger – and it’s happening faster than almost anybody predicted.” He says that Vestas, a Danish wind turbine manufacturer, will install a “15-megawatt (MW) wind turbine that will be powerful enough to provide electricity to roughly 13,000 British homes.”
But what is spurring companies to want to produce bigger wind turbines? Baraniuk has the 0: it’s cheaper, in terms of time and cost, to install a bigger structure with one base and produce 14 MW of power than to install two base structures for two turbines producing 7 MW each.
3. The biggest wind turbine in the world
While wind turbine companies are racing to build the biggest wind turbines ever seen, today, that title goes to MingYang Smart Energy, a Chinese company. CNBC.com reports that the company claims its turbine has “a height of 264 meters (866 feet), a rotor diameter of 242 meters and a blade length of 118 meters.”
CNBC.com also reports that “MingYang said the turbine would have a capacity of 16 megawatts and be able to produce 80,000-megawatt-hours of electricity per year, which it claimed would be enough to power over 20,000 households.”
4. Danger to wildlife
As the wind turbines become bigger, so do concerns about their adverse effects on wildlife, especially birds.
Regarding these adverse effects, Energy.gov says, “As with all energy supply options, wind energy can have adverse environmental impacts, including the potential to reduce, fragment, or degrade habitat for wildlife, fish, and plants.” Adding, “Furthermore, spinning turbine blades can pose a threat to flying wildlife like birds and bats.”
If you are still not convinced that the blades of wind turbines could be dangerous to birds and other flying wildlife, you probably don’t have an idea of the speed at which they move. The tips of the blades can move at speeds of up to 180 mph (290 km/h).
This is faster than the highest speed of most cars. However, the speed of the turbine is controlled so that it does not move too fast and damage the system.
5. The role of slip rings in wind turbines
One of the most important components in wind turbines are slip rings. The digital resource targeting professionals involved in the wind farm cycle, Windpowerengineering.com, defines a slip ring as “a solid metal and graphite or precious-metal wire brush, which contacts the outside diameter of a rotating metal ring.”
Slip rings have an important role in wind turbines. Their primary role is to provide a pathway for energy transfer between a wind turbine’s moving and static parts. Apart from facilitating power transmission, slip rings also transmit signals between the different parts of the wind turbine power generation system.
According to Windpowerengineering.com, “As the ring turns, electrical current or signal conducts through the brush to the metal ring making the connection.”
6. Why is wind power the largest renewable source in the U.S.?
According to the U.S. Energy Information Administration, in 2020, wind energy provided 43% of electricity generation from renewable energy. But why is wind energy pushing ahead of other sources like hydropower, biomass, and solar?
Energy.gov has the answer to the above question. The department says that wind energy is the largest renewable energy source in the U.S. because the country’s wind supply is abundant and cannot be exhausted. Another reason is that wind farms can be built on existing farms or ranches.
7. Investments into new wind power projects
Energy.gov reports that the U.S. installed nearly 17 GW of new wind capacity in 2020, taking the aggregate to almost 122 GW. To understand what this means in everyday language, let’s look at what 1 GW can do: it can light up 110 million LEDs.
Wind power projects also have an indirect contribution to the U.S. economy. For instance, the industry employs more than 120,000 full-time workers in the U.S. Farmers that make their land available for wind farms are also getting annual lease payments of around $3,000/MW of turbine capacity.
Globally, Bloomberg.com reports that the world spent a little more than $500 billion on renewable power in 2020. Europe invested €43bn ($50bn) in new wind farms amid the pandemic in 2020. This investment would see 20 GW of new capacity installed in the next few years.
In the U.S., it’s not surprising that Texas leads in the generation of electrical power using wind energy. Reporting for Scientificamerican.com, Robert Fares writes that Texas has more than double the wind generation capacity of any other state.
Fares reports that “Texas invested billions in high-voltage power lines linking Texas cities to windy West Texas way back in 2008.” This investment saw Texas generate 40% of its electricity for 17 continuous hours on December 20, 2016.
Worldpopulationreview.com reports that “Seven countries in Europe have achieved high levels of wind power penetration, including 41% of production in Denmark, 28% in Ireland, 24% in Portugal, 21% in Germany, and 19% in Spain.”
8. Wind prices per kilowatt-hour
According to the International Renewable Energy Agency (IRENA), renewable energy is progressively becoming cheaper than energy produced from fossil fuels. But what can you expect to pay for a kilowatt-hour of electricity produced from wind energy?
IRENA has the answer: In 2019, “Onshore and offshore wind both declined [in cost] about 9%, reaching USD 0.053/kWh and USD 0.115/kWh, respectively.”
9. The future of wind energy
Over the years, wind energy technology has been progressing rapidly. Energy.gov reports that modern wind turbines are more reliable, cost-effective, and have scaled up in size to multi-megawatt power ratings.
Apart from what we have already seen, new innovative technologies are being designed. For instance, the California Institute of Technology reports that “Engineers are in the early stages of creating airborne wind turbines, in which the components are either floated by a gas like helium or use their own aerodynamics to stay high in the air, where the wind is stronger.”
This article is shared by courtesy of ECO Industrial. Based in China, they are a slip ring and rotary union manufacturer with a renowned global clientele including Bosch, Simens, and Toyota. From through hole slip ring to capsule slip ring, they produce all sorts of slip rings.