Alternative Sources of Energy

It is not a secret that energy consumption has increased immensely in. the last decades. But do we have enough fossil fuels to satisfy our needs? As fossil fuels are nonrenewable we are highly interested in developing alternative sources of energy.

Solar Power is renewable. It is used for heating houses. Solar cells and furnaces make electricity from sunlight. Solar cells are expensive. Solar power isn't much use unless you live somewhere sunny. It doesn't cause pollution and doesn't need fuel.

Wind Power is renewable as well. It doesn't cause pollution; doesn't need fuel. However, a lot of generators are needed to get a sensible amount of power. It is necessary to put them where winds are reliable. And the noise can drive you nuts.

Hydroelectric Power plants are built for getting energy from flowing water. Usually we build a dam, and let the water turn turbines and generators as it goes through pipes in the dam. Renewable. No pollution, no fuel needed, no waste. Very expensive to build. Building a dam we flood a lot of land.

Waves Power. There's a lot of energy in waves on the sea. However it is not easy to get it. A wave power station needs to be able to stand really rough weather, and yet still be able to generate power from small waves. This source of energy is renewable - the waves will come whether we use them or not.

 

Geothermal Energy means heat from underground hot rocks. Hot water comes up and we use the heat to make steam to drive turbines, or to heat houses. It is renewable - so long as we don't take out too much, the energy keeps on coming. However, there are not many places you can do it - the rocks must be suitable. Sometimes we get poisonous gases coming up too.

"Biomass" means burning wood, dung, sugar cane or similar. It is renewable - we can always plant more trees. We burn the fuel to heat water into steam, which drives turbines, which drive generators. Burning anything we pollute the environment.

Nuclear (atomic) power stations use uranium as fuel. It is nonrenewable. Heat from the reactor turns water into steam, which drives turbines, which drive generators. It doesn't cause pollution unless something goes wrong.

Answer the following questions.

1. Why do we have to develop alternative sources of energy?

2. What is solar energy used for?

3. What are the disadvantages of wind power?

4. What requirements should hydroelectric power stations meet?

5. Why can the use of geothermal energy be dangerous?

6. Are nuclear power plants considered safe?

10. Name the sources of energy that are...

1. needing no fuel,

2. safe.

3. renewable,

4. pollution-free,

5. producing no waste,

 

Discuss the following questions.

a) How much do you know about copper?

b) Where is copper used today? Make a list of possible applications of copper. Compare it with that of your group mates.

c) Do you know any copper alloys? What are their constituents?

 

The students are at the seminar on metals technology. Read to their

Discussion and learn what properties copper has and where it can be

Used.

Teacher: Dear students, today we're going to discuss the main properties and applications of copper. So far, what can you say about this metal?

Andrew: If I'm not mistaken, copper is a non-ferrous metal. And it can be found in a free state in nature.

Alice: And as far as I remember, people were able to extract this metal in prehistoric times. Various things such as weapons, tools and decorations could be made of it.

Teacher: Very good. Were those copper tools very reliable?

Andrew: I think not. Pure copper is a soft ductile metal. Strong

cutting tools could be made only of copper alloys such as

bronze.

Teacher: OK. What are the present applications of copper?

Alice: Well, they are numerous. Copper metals can be used in most domestic appliances. Electrical industry is impossible without copper wiring as it is a very good conductor of electricity. Also, copper is corrosion resistant which makes it valuable for marine industry. Besides, this metal is even used in making money!

Teacher: You are quite right. Tomorrow we will be able to study the valuable properties of copper in the practical class.

 

Complete the dialogue.

Are we going....today?

-.... Let's remember what...

- I know that copper....

- Very well, and when....?

-…

-What applications....?

- …

- Why did bronze become so...?

- …

- Can you prove that copper... today?

- What valuable properties...?

- Well,...

Excellent! I see you know a lot about copper