Can wind turbines be used in vehicles?

Wind power

Hundreds of years ago, people used the power of the wind. They built windmills that turned the energy of the wind into a rotating motion. For example, they could drive mill wheels to grind grain. Because there is a lot of wind in the flat, seaside Netherlands, a particularly large number of windmills were built there: some of them are still in operation today.

Wind still provides us with energy, in the form of electricity. The modern wind turbines work in a similar way to the old windmills: huge rotors that look like propellers and are driven by the wind sit on a narrow tower. The rotation of the rotors is transmitted to a generator, which converts the energy into electricity like a dynamo. The stronger the wind blows, the more electricity can be generated.

Where there is a lot of wind - for example on the coast or on large areas - many wind turbines are combined to form large wind farms. Some even stand on platforms in the sea. In 2010, the first German offshore wind farm went into operation in the North Sea: Germany's first wind power plant in the sea. The electricity that is generated in this way is transported by power lines to the consumers.

Whether on land or at sea - wind farms have often been criticized: their construction and their rotational movement make noise and disturb people and animals. Some people do not find the sight of them beautiful either. But wind power has great advantages over other forms of energy: It is renewable. Because there will still be wind when crude oil, natural gas and coal have long been used up. And it is “clean” because it pollutes the air and soil neither with pollutants from burning fossil materials nor with radioactive waste from nuclear power.

27.4.2010

Germany's first offshore wind farm has gone into operation after seven months of construction. “Alpha ventus” is the name of the 250 million euro facility located 45 kilometers from the North Sea island of Borkum. In the future, the wind farm is to provide electricity for 50,000 households.

Far off the coast, the twelve test wind turbines from “Alpha Ventus” are in 30 meters deep water. It is by no means the first system of its kind: More than 300 wind farms in the North Sea are already supplying electricity from the high seas. In the Baltic Sea, too, there are already individual wind turbines that generate energy. Further systems are being planned or already under construction.

What speaks in favor of wind turbines on the high seas is that they can generate almost twice as much electricity as wind farms on land. However, the construction of the offshore systems is more complex and therefore more expensive. Most of the individual components have to be pre-assembled on land and then transported across the sea. Maintenance of the technology is correspondingly more expensive.

Nevertheless, experts assure that the future of wind power lies on the sea. Here the wind conditions are simply better than on land. The federal government plans that by 2030 more than half of the electricity generated by wind power will come from offshore plants. The wind turbines at sea should make a significant contribution to implementing the German energy transition.

Soundproofing for whales

When building wind turbines at sea, animals are exposed to high levels of noise, criticizes the Naturschutzbund Deutschland. Sea birds, many species of fish and especially the protected porpoises suffer from the noise that occurs when drilling and pouring foundations under water. Problem: The noise-sensitive harbor porpoises orient themselves and communicate using ultrasound. Sound waves under water could make them disoriented and permanent hearing loss could result. Now researchers are looking for effective soundproofing so that the animals are not excessively stressed.

How is wind created?

A fresh wind often blows on the coast. If it blows particularly hard, there is also talk of a stiff breeze. But not only by the sea - air is in motion all over the world. Only in a few places on earth does not the slightest breeze blow, as in the Kalmenzone at the equator - named after the French word for calm: "calme". This windless area was previously feared by seafarers, because the sailing ships stayed there for weeks. But why is it that sometimes there is calm and sometimes a violent storm sweeps across the country?

Wind is mainly created by the power of the sun. When the sun's rays heat up the ground, the air also warms up. The warm air expands and thus becomes thinner and lighter: the air mass rises upwards. This creates low pressure near the ground. In contrast, where it is cold, the air sinks and high pressure builds up on the ground. In order to equalize the pressure difference between neighboring air masses, colder air flows where warm air rises. This happens all the faster, the greater the temperature difference between the air layers. This is how the air gets into action - a more or less strong wind is blowing.

The formation of wind at the sea can be observed particularly well. During the day, the air warms up faster over land than over water. The warm air masses rise and suck in the cool and heavy air over the sea: The wind blows from the sea to the land. At night the wind changes direction. Because the water stores the heat longer than the land, the air above it is even warmer and rises. Then the wind blows from the land to the sea.

Where the wind blows from is always indicated with the direction of the compass. In our latitudes this is often from the west, we live in the so-called west wind zone. The hot trade winds, on the other hand, reliably blow from the east towards the equator. And the polar easterly winds transport icy air masses from the pole to the arctic circle.

Wind strength and wind speed

When smoke can rise vertically and there is hardly a breath of air to be felt, then there is no wind. In a hurricane, on the other hand, the wind is so violent that it pulls heavy objects with it. Wind can vary in strength - and the strength of the wind is indicated on the “Beaufort scale”, which ranges from wind force 0 with complete calm to a hurricane with wind force 12.

The scale is named after the British Sir Francis Beaufort, who used a similar scale a good 200 years ago. At that time, the wind strength was determined by, for example, observing the height of the waves on a ship or the effect of the wind on the sails and then reading off the appropriate wind strength in a table. Today, every wind strength has a certain wind speed. For example, wind force 0 means that the wind is blowing less than one kilometer per hour. So it is imperceptible - there is no wind. If, on the other hand, the wind has a speed of 39-49 kilometers per hour, i.e. almost as fast as a car drives in the city, then large branches are already moving. Such a strong wind has wind force 6. At wind speeds of more than 62 kilometers per hour, there is talk of a storm. And a hurricane is on the way when the wind speed exceeds 118 kilometers per hour: This corresponds to the highest value on the scale, wind force 12. In this case, severe devastation is to be expected.

By the way, the strongest wind ever measured at the earth's surface was blowing in April 1996 at a whopping 408 kilometers per hour over the island of Barrow Island in Western Australia. Such a violent storm can blow railroads off the rails and collapse buildings like houses of cards. The storm also wreaked havoc on Barrow Island.

Fossil fuels: petroleum, natural gas and coal

It is called black gold because of its color and because it is so valuable to us: We are talking about petroleum. The raw material was created 150 million years ago when dinosaurs still inhabited our planet. Today it is hard to imagine our everyday life without crude oil: We need it as fuel for vehicles, as heating material or as the basis for plastic.

The raw material for crude oil is plankton, which floated in the sea millions of years ago. The remains of these tiny sea creatures sank to the bottom and were buried airtight under other layers of sediment, such as sand and clay. The remains decomposed and turned into digested sludge. More sediments were deposited above this, the weight of which pressed on the digested sludge. Under this pressure the temperature rose and the digested sludge chemically changed to a mixture of gaseous and liquid hydrocarbons: crude oil. Because it was lighter than water and the surrounding rock, it rose through pores and higher and higher until it hit an impermeable layer under which the viscous mass was collected: an oil reservoir was created.

Natural gas was also produced under conditions similar to those of oil. This is why both fuels are often found in one deposit. Natural gas is lighter, which is why it is stored on top of oil. Because both substances are fossil remains of marine organisms, they are referred to as "fossil" fuels.

Coal is one of the fossil fuels. It owes its origin to the remains of dead marsh plants. These formed increasingly thick layers of peat, over which sediments piled up. Under their weight, water, oxygen and other gases were pressed out of the peat layer, and the proportion of carbon increased. Over the millennia, the peat turned into lignite. If the sediment cover grew and the pressure continued, brown coal became fat or hard coal. In order to be able to use their stored energy, the coal deposits - also called coal seams - are extracted in mines.

What pollutes the air?

A thick cloud of haze hangs close to the floor. Such a gray veil of fog can often be seen, especially in large cities and metropolitan areas. Here the air quality suffers from the fact that a lot of dust particles are floating around. Because they are too small to be seen with the naked eye, these suspended particles are also known as particulate matter. In addition to fine dust, there are also toxic gases such as carbon monoxide or sulfur dioxide, which float in the lower atmosphere and pollute the air.

A large part of these exhaust gases are produced when crude oil, coal and other substances are burned. Cars, power plants, waste incinerators and residential heating systems blow loads of dirt into the air. In addition, there is dust that is blown up - from streets, but also from factory farming, for example. The “exhaust gases” from the livestock also contribute to the fact that the air is getting worse and worse. But it is not always humans who pollute the air: volcanic eruptions can also contribute to higher levels of fine dust in the atmosphere.

The more pollutants there are in the air, the worse it is for our health: the respiratory tract can become ill, and the circulatory system and brain are damaged. Not only humans and animals suffer from the polluted air, plants are also damaged: If too much carbon dioxide and sulfur oxide are suspended in the air, acid (carbonic and sulfuric acid) forms in connection with water. The result is what is known as “acid rain”, which makes the soil acidic. Plants growing on such soil become withered and die. We are talking about "forest dieback". This can also happen far away from where the exhaust gases get into the air, because the wind carries the acid rain clouds away for hundreds of kilometers.

Air pollution is particularly bad in metropolises in India, Pakistan and Iran or in Mexico City. In Germany there are regulations on how heavily the air can be polluted. But here, too, the values ​​are not always adhered to and car traffic continues to increase.

In order to keep pollutants in the air low, it is therefore particularly important that enough forests and parks clean the air. Because trees, like all green plants, absorb carbon dioxide from the air and produce the oxygen that is essential for us. “Green lungs” in large cities, i.e. green spaces and forests close to cities, are therefore particularly important for our health. And those who often get on their bikes instead of driving the car also help to keep the air clean.