Make the following words negative by adding the prefixes in- or un-.

Example: adequate – inadequate

1) appropriate; 2) consistent; 3) economical; 4) effective; 5) efficient; 6) reliable; 7) sufficient; 8) suitable.

 

6. a) In pairs, answer the following questions about wind turbines:

1) What function do wind turbines perform?

2) What are the main advantages and disadvantages of wind turbines?

3) What types of location are most suitable for wind farms?

 

b) In pairs, discuss the functions of the following wind turbine components.

A) BLADE               B) TOWER              C) GENERATOR

7. a) Listening 6. Mike, Loretta and Hanif, engineers at a wind turbine constructor, are discussing performance and suitability issues relating to offshore wind turbines. Listen to the conversation and answer the following questions.

1) Which wind turbine component do the engineers discuss?

2) What is the big problem with offshore installations?

3) Which two types of construction material are being compared?

4) Why are costal defences mentioned?

5) What point does Hanif make about regular maintenance?

6) What comparison needs to be made with regard to lifespan?

 

b) Listen again. What issues do Mike, Loretta and Hanif agree and disagree on?

8. a) The following information is from the web site of Sigma Power, a firm that advises corporate and government clients on wind energy projects. Complete the text using the words in Exercises 4, 5.

WIND TURBINES – FACT FILE

The fact that wind turbines consume no fuel and waste very little energy is clearly a fundamental advantage. But just how 1) efficient they are? Key figures

Clearly, wind turbines need to be located on relatively windy sites in order to function. From a meteorological standpoint, what kinds of geographical location are the most 2) _______?

Turbines are generally placed at the tops of tall towers, where wind speeds are higher, thus making them more 3) _______. What other positioning factors influence performance?

Wind turbines rarely function continuously, due to the fact that wind speeds are 4)__________. How significant is the impact of variable weather conditions on power generating capacity?

Transmitting electricity over long distances is inherently 5)________, due to power losses from overhead or underground power lines. Find out more about the advantages of generating power locally.

The generating capacity of wind turbines is generally 6) _______ for it to be relied upon 100%. What percentage of total generating capacity can wind turbines realistically provide?

Some early wind turbines were 7)_________, suffering breakdowns caused by inaxial stresses stemming from higher wind loads on the upper blade. However, this problem has been overcome on modern units. Learn more about the technical evolution of wind turbines.

 

b) You are engineers at Sigma Power. The marketing manager has asked you to provide some technical answers for the frequently asked questions section of the company’s website. The FAQ section is aimed primarily at potential clients who are thinking of installing wind turbines at their sites – factories, office complexes, hospitals, and university campuses. In pairs, discuss the following questions and write the answers for the website using the information in the fact file and your own knowledge.

Frequently Asked Questions

A common-sense introduction to wind turbines

 

1) What’s the big advantage of having a wind turbine at my site?

2) How dependable wind turbines as a source of power, given that weather conditions are changeable?

3) What kinds of site are most suitable for wind turbines, relative to natural factors such as hills, the coast, and height above sea level?

4) What’s the most appropriate location for my wind turbine, relative to features on the site, such as trees and buildings?

 

Describing Physical Forces

9 a) Read the following article. What is a solar tower and how does it use the forces of expansion and pressure?

Solar Towers