Renewable sources of energy

The sun constantly gives off energy in the form of light and heat.

Earth receives enough solar energy to meet the energy needs of the entire world for 40 years.

Advantages:1. It does not cause pollution2. Abundant availability, It will not.Disadvantages:3. Its only available when the sun is out and it is

very spread out.

Solar Energy

Solar Plants: Rows of giant mirrors focus the sun’s rays to heat a tank of water. The water boils, making steam that is used to generate electricity.

Solar Cells: consists of a “sandwich” of very thin layers of the element silicon and other materials.

Solar Technologies

Exploring a Solar House

Passive: converts sunlight into thermal energy without using pumps of fans.

Active: captures the sun’s energy, then uses fans and pumps to distribute the heat.

Solar Heating Systems

Wind energy is an indirect form of solar energy.

The differences in pressure cause winds as air moves from one area to another.

Wind can be used to turn a turbine and generate electricity.

Wind

WIND POWER

Hydroelectric power is electricity produced by flowing water.

It is the most widely used source of renewable energy in the world today.

Advantages:1. It is inexpensive.2. No pollutions3. Provides a steady supply of

energy.

Hydroelectric power

Tides are another source of moving water.

The gravity of the moon and sun causes the water on Earth’s surface to rise and fall on its shores.

A few tidal power plants have been built to take advantage of this regular motion.

Tidal Energy

The oldest fuel used for heat and light is wood.

Other biomass fuels are leaves, food, wastes and manure.

Biomass materials can be converted into other fuels;

1. Gasohol-corn makes alcohol, add alcohol to gasoline produces fuel for cars.

2. Bacteria decomposes turns into methane gas is used to heat buildings.

Biomass Fuels

BIOMASS ENERGY

Intense heat from Earth’s interior. Geothermal energy is an unlimited source

of cheap energy. Disadvantages:1. Only a few places where magma comes

close to Earths surface. (Iceland)2. Need to drill deeper wells (expensive)

Geothermal energy

Energy of the future:1. Burns cleanly2. Water is its only by-product3. It creates no smog, smoke or acid rain.4. Can be handled and transported

through pipelines.5. Exists on Earth in large supply.Disadvantage:Almost all of Hydrogen is combined to

Oxygen

Hydrogen Power

Hydrogen Power