Reading 2

Unit 10- Reading 2

Page 153

Using renewable energy sources

Over the last 200 years, humans created many machines to help them do work. Most machines were powered by burning fuels such as coal. gasoline, and natural gas. Other machines were powered by electricity.

Now scientists are suggesting that we look for ways to use natural forces to help us do work. The scientists are suggesting that we use wind, water, and the sun as sources of power to create electricity. Sun, wind, and water are all renewable resources. They will always be available to our growing world population.

USING WAVE POWER

The power of ocean waves as they approach land is very strong. For this reason, engineers believe ocean waves have great potential as a force to create electricity. Engineers are developing technology to use that force. One plan for a wave farm includes putting several large fiberglass tanks in the ocean and securing them to the ocean noor. The tanks would be connected to each other.

They would float on top of the water. As powerful ocean waves approached land, the tanks would rise and fall with the water. The motion would spin turbines inside the tanks to generate electricity. The wave farm would be connected to shore. Engineers estimate that one tank would generate enough electricity to power one house. This approach would work in most areas that have a sea coast.

USING WIND POWER

A similar concept is now being used to create electricity using wind power. This approach works best in areas that have strong, steady winds. Engineers have created wind farms to collect the power of the strong winds. They put hundreds of wind machines in windy places. A wind machine is a very tail pole.

At the top is a propeller with several long blades. When strong winds blow, the blades of the wind machines turn. The turning blades power machinery in nearby turbines to generate electricity. The electricity derived from a wind farm is then sent to nearby consumers.

USING SOLAR POWER

Another concept uses the sun to generate electricity.

In areas that are sunny throughout the year, hundreds of collection devices are put into a large field. Each solar collection device consists of a pole with a large mirror on top. The mirrors reflect heat from the sun. The heat obtained from the mirrors is used to boil water. Steam from the boiling water turns machinery in a turbine to generate electricity for nearby consumers.

Scientific data Indicate that generating electricity by using water, wind, and solar energy will benefit the world. However, at a local level, many people do not like these projects. They complain thatwave farms destroy beautiful beaches. They also worry that a wave farm might affect whales and fish that swim in the water. Likewise, people complain that wind machine propellers are killing birds that fly too close to the blades.

Others complain that rows of solar panels are ugly. They also say that the solar panels take up space that could be used for farming or recreation.

The choice is a difficult one. We need to consider both present and future needs when we decide how to obtain energy and how we consume it.