Wind Energy 101 Session!

Welcome back to my technology series!

Ever seen a wind turbine and wondered how it worked? 

Well, it's a rather windy day in London as it is! Brrghhhhh...I must admit that it's cold. 

You've definitely come to the right place for a quick crash course on wind turbines.

http://www.sourcewire.com/news/43190/opus-energy-helps-businesses-profit-from-their-wind-turbines-eagle#.VIC6saSsU8Z

Wind energy is electricity generated from a wind turbine. 

A simple explanation...

The wind drives the blades of the turbine and the spinning action makes electricity from generators. In order to prepare this electricity for transmission, a transformer is used to increase the voltage. Local transformers are used to step down the voltage for industrial and domestic consumption (Hau and Von Renouard, 2013). 

Want more? Here's a more technical insight...

If you get over the robotic voice, the videos are very informative. 

How do Wind Turbines work ?

Wind Turbine Design

The most commonly used wind turbine is the Horizontal Axis Wind Turbine (HAWT) (Burton et al, 2011). The kinetic energy from the wind drives the blades of the turbine. A generator within the turbine transforms mechanical energy to electricity energy.

The key aim is to maximise the aerodynamic efficiency and power extracted from the wind. 

However, there are several factors to take into account when thinking about wind turbine design (Manwell et al, n.d.):

- The number of blades: Are there significant gains if we were to put more blades on?
- Blade shape
- Length of the blades
- The height of the wind turbine

Since power input available for the wind turbine varies as a cubic of wind speed, a small change in wind velocity would have a large impact on power generation (see video above for details). 


Well, a taller wind turbine is the solution for more energy right? 

The answer? It's not that simple I'm afraid. 

Advantages:

- Through implementing algorithms, blades are specifically designed for maximum power extraction.
- Renewable energy resource.

Disadvantages:

- Power fluctuations due to the sensitivity to wind speed.
- Road transportation and structural design are key concerns. 
- Visual and noise pollution.

>>>>>> LINK TO THE TOP 10 BIGGEST TURBINES IN THE WORLD <<<<<

Transmission of Electricity Generated

In relation to transmission of the electricity produced, a high voltage is essential and there are many ways that this can be achieved. The main ones are alternating current (AC) and direct current (DC) technologies, although engineers favour the latter (Gonen, 2014). 

AC transmission links have several disadvantages (Siemens, 2011) :

- Limits to transmission capacity and distance. 
- Direct connection between two AC systems with different frequencies is not possible. 
- Inability to combine AC systems of the same frequencies as this can cause system instability. 

Siemens has been working on improving High Voltage Direct Current (HVDC) lines as an alternative to the AC system. HVDC improves the reliability and efficiency of transmission. I won't elaborate on this here, but take a look at this >> LINK <<. If you're feeling adventurous, this PDF file offers a detailed overview. 


That's it from me. Check out the discussion section of the blog website for an analysis of wind energy applications. Is wind the way forward for energising the future? 


Some references:

Burton, T., Jenkins, N., Sharpe, D., & Bossanyi, E. (2011). Wind energy handbook. John Wiley & Sons.

Gonen, T. (2014). Electric power distribution engineering. CRC press.

Hau, E., & Von Renouard, H. (2013). Wind turbines: fundamentals, technologies, application, economics. Springer.

Manwell, J. F., McGowan, J. G., & Rogers, A. L. Wind Turbine Design. Wind Energy Explained: Theory, Design and Application, 247-320.