Renewable Energy Resources 13 Renewable Energy Resources Photo © Borut Trdina/iStockphoto

13.2 What Are Sources of Renewable Energy? Energy that is naturally replenished and that comes from the sun, flowing water, wind, Earth’s interior heat, biomass Renewable energy will be cheaper if we eliminate: Inequitable subsidies Inaccurate prices Artificially low pricing of nonrenewable energy

Hydropower as a Renewable Energy Resource We can use water flowing over dams, tidal flows, and ocean waves to generate electricity. However, environmental concerns and limited availability of suitable sites may limit the use of these energy resources.

We Can Produce Electricity from Falling and Flowing Water Hydropower Uses kinetic energy of moving water Indirect form of solar energy World’s leading renewable energy source used to produce electricity, least expensive Hydropower plant Water from dam reservoir flows, turns turbines that spin generators Micro-hydropower generators: floating turbines

We Can Use Tides and Waves to Produce Electricity Produce electricity from flowing water Ocean tides and waves in coastal bays and estuaries Power systems are limited Few suitable sites High costs Equipment damaged by storms and corrosion

Wind Power as a Renewable Energy Resource Wind power is the world’s second-fastest growing source of electricity after solar cells. When we include the environmental costs of using energy resources in their market prices, wind power is the least expensive and least polluting way to produce electricity.

Using Wind to Produce Electricity Is an Important Step Toward Sustainability Tall, long-blade turbines can extract more energy from the wind. Rapidly growing power source United States, Europe, and China Future is offshore wind farms Wind power has potential to produce 40 times the electricity currently used worldwide.

Case Study: The Potential for Wind Power in the United States Wind energy—wind farms convert to electrical energy Wind power is inexhaustible. Could meet electricity needs of the lower 48 states Texas and California are top producers What do you know about renewable energy options available in your community?

Wind Power Wind Power: Wind turbines convert the kinetic energy in wind to electricity. Wind power is an indirect form of solar energy.

Advantages and Disadvantages of Wind Power Abundant, widely distributed, inexhaustible High net energy Low electricity cost Nonpolluting Disadvantages Largest potential areas are usually rural Need backup power source on calm days May be considered noisy, eyesore