Tobie Green Energy

Wind Basics

Wind Is Powering Our World!

Around the world, turbines are sprouting out of the ground making wind one of the fastest growing sources of electricity in the world today.  Wind provides clean domestic energy, which delivers clear economic, environment and social benefits.  Wind farms are not the only answer.  The space and investment required for utility-scale development precludes many places form participating in the wind power revolution.  Thus, the growing demand for local wind projects…and our drive to meet our customers where they live and work.
What is modern energy?

All over the world, people must prepare to use new forms of energy in the future. The sharp rise in energy consumption calls for a sustainable resource that does not create more greenhouse gases, pollution or waste for future generations. Wind power is a sustainable, predictable and clean source of energy. Substantial capacity can be built up quickly, offering energy independence demanded by the world's largest and fastest-growing economies. That's why we call wind power, modern energy.

How does wind arise?

Wind arises from pressure differences in the atmosphere. The greater the difference in pressure, the more powerful the wind can be. There are various types of wind:

Local wind

Local weather systems are often caused by uneven heating of the Earth’s surface by the sun. Areas subject to local wind systems are ideal locations for wind turbines. When planning wind farms, a lot of work is done to find precisely the places where the wind is most optimal. However, places where strong wind gusts can damage the turbines are avoided.

Extratropical low pressure systems

Wind power is not only generated in areas with local wind systems. Most wind turbines are located in what is known as the westerlies: The broad zones north and south of the tropics where the wind is usually blowing west. This is where large passing lows and storms (extratropical cyclones) determine wind and weather conditions.

Trade winds and monsoons

Tropical and subtropical wind systems dominate the area near the equator. Also known as trade winds and monsoons, these winds blow across the sea from the subtropical high-pressure areas located around 30 degrees latitude north and south of the equator. The Earth’s rotation deflects the winds to the right in the northern hemisphere and to the left in the southern hemisphere.

Shape of the landscape

The shape of the landscape has a significant effect on the strength and stability of the wind. When installing wind turbines, it is best if the wind can blow freely across the turbines from all directions. This is why turbines should ideally be installed away from cities. Offshore turbines produce the most energy. At sea, there are other challenges to take into account. For example, the costs of installation are typically higher than for onshore turbines.

How does it work?

Wind turbines use the energy from the wind to generate electricity. A wind turbine consists of four large main components:

• Foundation unit
• Tower
• Nacelle (turbine housing)
• Rotor

From wind to electricity

Wind turbines use energy from the wind in order to generate electricity. They do this with their blades, which capture the wind and turn. When there is no wind, the blades will remain at a 45-degree angle so that the turbine can draw maximum energy from gentle winds. Turbines begin to produce energy when wind speeds reach about four meters per second. The blade gradually rotates towards an angle of 0 degrees with the broad surface facing the wind. When the wind strikes the blade, it creates positive pressure on the front of it and negative pressure behind it. In other words, the wind pushes against the front edge and creates a suction effect behind the blade, which makes the rotor turn. At maximum rotational speed, the blade tips reach a speed of 250 km an hour.

Connecting to the grid

The generator is connected via the turbine’s electrical control system. The electrical output is lead through a high-voltage transformer to the grid, which supplies people with electricity. In just 2-3 hours, a V90-3.0 MW turbine can produce enough power to cover the annual electricity consumption of an average European household.

Output regulation

There are three ways of regulating output: 1) Passive stall, where turbines operate at a fixed rotational speed with non-adjustable blades. 2) Active stall, where turbines operate at a fixed rotational speed with adjustable blades. 3) Pitch, where turbines operate either at a constant rotational speed or with variable speed. The leading edge of the blade is turned into the wind to reduce uplift.  The turbine stops when the wind exceeds 25 meters per second, since wind speeds above this level place too much strain on turbine components.