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Animation: How Wind Turbines Work

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The windmill, which converts wind into rotational energy to mill grain or pump water, has been around since antiquity. It’s even been claimed that Ancient Babylonians planned to harness wind as early as almost 4,000 years ago, as part of a scheme for one of Hammurabi’s ambitious irrigation projects.

By the end of the 19th century, wind energy took on a whole new meaning as engineers in Scotland, Denmark, and the United States invented the first wind turbines that generated electricity. Many technological improvements have been made since, and now modern wind farms dot the landscapes of countries around the world.

Related Topic: What it Would Take to Power New York City

Today, wind power is an important element of the green energy mix, and its estimated that 432 GW of wind farms are installed globally. In the United States, nearly 5% of all power is now generated by wind.

How Wind Turbines Work

How Wind Turbines Work

How do these massive propellers get into motion? Once they are turning, what do they do?

As shown in the animation, it’s all about the lift and drag forces created by the shape of the blades. Lift acts perpendicular to the direction of wind flow and drag acts parallel to the direction of wind flow.

How Wind Turbines Work

The blades are designed so that when wind passes, a low-pressure pocket of air is created by faster moving wind on the curved side of the blade. This sucks the blade in the downwind direction, creating lift. The blades are then connected to a series of shafts that spin an electromagnetic induction generator, and this creates electricity.

There are some other bells and whistles that help to maximize efficiency in a modern wind turbine as well.

The anemometer measures wind speed, while the controller starts and stops the turbines to operate only at desirable wind speeds (between 8 and 55 kmph). The wind vane measures the wind’s direction and communicates this information to the yaw drive, which helps make adjustments to the turbine’s orientation. Lastly, there is also a braking system installed which can be used for emergency stops when wind speeds get too extreme.

Original graphic by: SaveOnEnergy

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Economy

What is a Commodity Super Cycle?

The prices of energy, agriculture, livestock and metals tell the story of human development. Learn about the commodity super cycle in this infographic.

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Visualizing the Commodity Super Cycle

Since the beginning of the Industrial Revolution, the world has seen its population and the need for natural resources boom.

As more people and wealth translate into the demand for global goods, the prices of commodities—such as energy, agriculture, livestock, and metals—have often followed in sync.

This cycle, which tends to coincide with extended periods of industrialization and modernization, helps in telling a story of human development.

Why are Commodity Prices Cyclical?

Commodity prices go through extended periods during which prices are well above or below their long-term price trend. There are two types of swings in commodity prices: upswings and downswings.

Many economists believe that the upswing phase in super cycles results from a lag between unexpected, persistent, and positive trends to support commodity demand with slow-moving supply, such as the building of a new mine or planting a new crop. Eventually, as adequate supply becomes available and demand growth slows, the cycle enters a downswing phase.

While individual commodity groups have their own price patterns, when charted together they form extended periods of price trends known as “Commodity Super Cycles” where there is a recognizable pattern across major commodity groups.

How can a Commodity Super Cycle be Identified?

Commodity super cycles are different from immediate supply disruptions; high or low prices persist over time.

In our above chart, we used data from the Bank of Canada, who leveraged a statistical technique called an asymmetric band pass filter. This is a calculation that can identify the patterns or frequencies of events in sets of data.

Economists at the Bank of Canada employed this technique using their Commodity Price Index (BCPI) to search for evidence of super cycles. This is an index of the spot or transaction prices in U.S. dollars of 26 commodities produced in Canada and sold to world markets.

  • Energy: Coal, Oil, Natural Gas
  • Metals and Minerals: Gold, Silver, Nickel, Copper, Aluminum, Zinc, Potash, Lead, Iron
  • Forestry: Pulp, Lumber, Newsprint
  • Agriculture: Potatoes, Cattle, Hogs, Wheat, Barley, Canola, Corn
  • Fisheries: Finfish, Shellfish

Using the band pass filter and the BCPI data, the chart indicates that there are four distinct commodity price super cycles since 1899.

  • 1899-1932:
    The first cycle coincides with the industrialization of the United States in the late 19th century.
  • 1933-1961:
    The second began with the onset of global rearmament before the Second World War in the 1930s.
  • 1962-1995:
    The third began with the reindustrialization of Europe and Japan in the late 1950s and early 1960s.
  • 1996 – Present:
    The fourth began in the mid to late 1990s with the rapid industrialization of China

What Causes Commodity Cycles?

The rapid industrialization and growth of a nation or region are the main drivers of these commodity super cycles.

From the rapid industrialization of America emerging as a world power at the beginning of the 20th century, to the ascent of China at the beginning of the 21st century, these historical periods of growth and industrialization drive new demand for commodities.

Because there is often a lag in supply coming online, prices have nowhere to go but above long-term trend lines. Then, prices cannot subside until supply is overshot, or growth slows down.

Is This the Beginning of a New Super Cycle?

The evidence suggests that human industrialization drives commodity prices into cycles. However, past growth was asymmetric around the world with different countries taking the lion’s share of commodities at different times.

With more and more parts of the world experiencing growth simultaneously, demand for commodities is not isolated to a few nations.

Confined to Earth, we could possibly be entering an era where commodities could perpetually be scarce and valuable, breaking the cycles and giving power to nations with the greatest access to resources.

Each commodity has its own story, but together, they show the arc of human development.

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Energy

Visualizing U.S. Energy Use in One Giant Chart

This interesting diagram breaks down all U.S. energy use by both source and industry, and everything that happens in between.

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Visualizing U.S. Energy Use in One Giant Chart

If you feel like you’ve seen this diagram before, you probably have.

Every year, it’s assembled by the Lawrence Livermore National Laboratory, a research center founded by UC Berkeley and funded primarily by the U.S. Department of Energy.

The ambitious aim is to chart all U.S. energy use in one Sankey diagram, including the original energy source (i.e. nuclear, oil, wind, etc.) as well as the ultimate end use (i.e. residential, commercial, etc.) for the energy that was generated.

U.S. Energy Use in 2018

According to the research center’s most recent published version of the diagram, U.S. energy use totaled 101.2 quads in 2018.

In case you are wondering, a single quad is equal to 1 quadrillion BTUs, with each quad being roughly equivalent to 185 million barrels of crude oil, 8 billion gallons of gasoline, or 1 trillion cubic feet of natural gas.

Here is how the recent figure compares to previous years:

YearU.S. Energy Consumption% Fossil Fuels in Mix
2018101.2 quads80.2%
201797.7 quads80.0%
201697.3 quads80.8%
201597.2 quads81.6%
201498.3 quads81.6%

As you can see in the table, U.S. energy use has been generally increasing, eventually topping 100 quads per year by 2018. During this time, the total percentage of fossil fuels in the mix has dropped, but only from 81.6% to 80.2%.

Taking a closer look at the data, we can see that the largest percentage increases in the mix have come from solar and wind sources:

Source20142015201620172018Change ('14-'18)
Solar0.4270.4260.5870.7750.949+122%
Wind1.731.782.112.352.53+46%

Energy use measured in quads (1 quadrillion BTUs)

Solar use has increased 122% since 2014, while wind jumped 46% over the same timeframe. Not surprisingly, energy derived from coal has fallen by 26%.

Dealing With the Rejects

One interesting thing about the diagram is that it also shows rejected energy, which represents the energy that actually gets wasted due to various inefficiencies. In fact, 68% of all energy generated is not harnessed for any productive use.

This makes sense, since gasoline engines are usually only about 20-40% efficient, and even electric engines are 85-90% efficient. Put another way, a certain percentage of energy is always released as heat, sound, light, or other forms that are hard for us to harness.

As electric cars rise in popularity and as modern gas-powered engines also get more efficient, there is hope that the amount of this rejected energy will decrease over time.

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