V. Energy quiz.

1. Which one is not a fossil fuel?

a) oil b) wood c) coal

2.What percent of energy used around the world comes from fossil fuels?

a) none b) 90% c) 40%

3. Which of these sources is renewable?

a) natural gas b) coal c) wind

4. This source of energy is not weather dependent.

a) hydro-energy b) solar energy c) geothermal

5. The largest primary source of electrical energy is … .

a) uranium b) coal c) natural gas

Where do we get energy?

I. Read and translate the text. Use your dictionary.

Just a few hundred years ago people were using a tiny fraction of energy consumed today. Every day we need more and more energy to run our factories, airplanes, cars, ships, computers and other modern marvels. Some of the energy we now consume comes from burning petroleum that is derived from oil. Other major energy sources include coal, natural gas and uranium. Unfortunately, using these materials leads to numerous environmental problems. In addition, none of these energy sources is renewable.

In other words their supplies are limited and become harder to get every day. Although there are different opinions as to the amount of fossil fuels (oil, coal, natural gas) left on the planet, very few scientist would venture to say that we have more than a 50-year supply of these fuels. A typical car with an internal combustion engine is an example of energy being used exactly where it was produced. The engine takes gasoline, burns it, and converts the gasoline chemical energy into mechanical energy which is transferred to the wheels and moves the car.

Another way to use energy is at a location different from where it was produced. If you are reading this text on a computer, chances are your computer receives electric energy from a power plant that is located tens, hundreds or even thousands of kilometers away. Electrical energy can be relatively easily and cheaply transferred over large distances. That’s why it is currently the main secondary energy source.

Different electric power plants may use all kinds of primary energy sources (such as coal, oil, uranium, wind, hydropower, solar power, biomass), but their final product is the electricity that can be conveniently sent, almost at the speed of light, to another location where it’s needed. Even though modern power plants incorporate some amazing scientific and technological achievements, the basic idea has not changed much since the first electric power plants built at the end of the 19^th century. In the majority of cases, electric power is produced by electrical generators attached to turbines. The turbines can be rotated by steam, water or wind. Steam can also be generated by burning fossil fuels or biomass. Steam can also be produced by heat generated in the nuclear reactor.