What is Wind Energy?

•Wind is the circulation of air caused by the uneven heating of the earth’s surface.

Wind energy is energy created by harvesting the wind.

• During the day, the air above the land heats up quicker than the air over water. The warm air over land expands and rises and the heavier cooler air rushes in to take its place which creates wind.

Is wind a renewable or nonrenewable energy resource?

•Wind is a renewable energy resource because it can be replenished.

Ways in which we turn wind into energy we can use:

• Windmills or Wind Machines• Wind machines uses the motion of the wind ,

which turns a turbine therefore producing electricity.

Wind Machines

What are the effects of wind energy on the environment?

• Wind machines and windmills are very clean and produce no air or water pollution.

• Wind machines take up a lot of land, but most of the land can be used for other things at the same time such as farming and grazing cattle.

• There are also concerns about birds and bats getting caught in the wind turbines.

Disadvantages of wind energy:• Wind machines do not produce a lot of

electricity.• Wind machines do not produce all the time

because the wind isn’t constant.• Wind machines can’t work just anywhere;

there must be stable, continuous wind resources.

What is Hydroelectric Power?

• Hydroelectric power is the force of moving water caused by gravity.

• How is the water cycle involved in hydroelectric power?

Sun

Condensation

Precipitation

Evaporation

Transpiration

Run-off

http://www.ecomentors.ca/pub/assets/pdfs/water_cycle_worksheet.pdf

How can we turn hydroelectric power into energy we can use?

• Hydroelectric Power is a renewable energy source.

Hydroelectric Power

• We can harness the energy in flowing water by damming rivers and using waterfalls.

Hydroelectric Power

Hydroelectric Power

Dams

• Construction of a dam takes a lot of planning. They consider the site, hydrological studies, and environmental impact.

• Also new sites for dams usually tend to require extensive power transmission lines - $$$$.

• Although, once completed if it is well designed and maintained then the hydroelectric power source is relatively cheap and reliable.

Grand Dam and power plantPicture found at: http://apps1.eere.energy.gov/education/lessonplans/pdfs/hydropower.pdf

Effects of hydroelectric power on the environment:

• Dams can flood land and disrupt animal and fish habitats.

• Hydroelectric power doesn’t pollute the air, but it can churn up sediments in the water.

Hydroelectric Power

• Hydropower dams are the cheapest and cleanest way to produce electricity.

• There are few places in the U.S. to create dams because most suitable rivers have already been dammed.