Alternative EnergyAlternative Energy Sources Tides Biomass Fuel Cells

By: Sam Born and Scott Myers

TIDESDiscovery of Tides

• In the seventeenth century, Sir Isaac Newton discovered that tides are caused by a gravitational pull exerted by the moon

• This pull has a very small effect on the landmasses on Earth, but since the oceans’ waters are liquid, this pull effects the movement of the water, therefore causing tides

• Sir Isaac Newton also found that when the gravitational pull is exerted, the oceans bulge outward

• These bulges, which are located along an invisible line pointing towards the moon, are called lunar tides

• Lunar tides are the rise and fall of sea levels caused by the gravitational pull of the moon

TIDESCreating Tidal Power

• Tidal power is the use of the ocean’s tides to generate energy and eventually electricity

• Tidal power is converted from kinetic energy into mechanical energy when the flow of the tides spin the underwater rotors of the generator

• The energy collected in the rotors then moves to a gearbox where extra gears help produce more energy (similar to wind turbines). The energy is then converted to electricity and brought through underground wires back to land.

• Two main types of turbines:1. Tidal Barrage – a barrier that traps water at high tide,

creating a tidal basin2. Tidal Stream Generator – a turbine with underwater rotors

that converts tidal power to energy

TIDES

TIDESCurrent Uses

• The first tidal power station was set up in La Rance River, France in 1966

• Major producers of tidal power are France, United Kingdom, Russia, Canada, and Australia

• Only 22 sites in the world were declared fit for a tidal power plant

• Tidal power is not common because many countries do not want to spend a lot of money on plants

TIDESAdvantages and Disadvantages

Advantages Disadvantages• No pollution • Expensive to build• Endlessly renewable resource

• Hard to find a good location

• Requires no fuel • Negative impact on environment (Fish, marine mammals, and birds)

• High efficiency • Disrupts tidal cycles• Plants can last up to 100 years

• Reduces kinetic energy in the ocean

TIDES

Biomass

BiomassBasic Biomass

• Biomass is a clean renewable energy from organic material

• Biomass energy usually comes from wood, waste, alcohol fuels, crops, and landfill gases

• Biomass fuel can be taken from dead material

• Plants and trees die from natural causes • Because we are going to continue making waste products, and plants and trees are going to continue dying, Biomass is renewable.

BiomassHow Biomass Works

• The waste or wood is gathered in trucks and transported to a biomass plant

• At the plant, the waste is fed into furnaces

• The heat is then used to boil water and the energy from the steam is used to rotate turbines and generators

• The turbines produce electricity which is then distributed through the power grid to towns and cities

Biomass

BiomassCurrent Uses

• The top producer of biomass energy is Finland. 20% of Finland’s energy is biomass

• Other nations include Sweden, Austria, United States, and Brazil

• Biomass energy is a good alternative for fossil fuels because it burns cleaner

Advantages and Disadvantages

Advantages Disadvantages• Does not add many CO₂ emissions to the air

• Collecting enough waste can be difficult

• Cheap to produce • Although very little, it creates greenhouse gases

• Can reduce dependence on foreign oil

• Necessary materials aren’t always available.

• Will eliminate waste

Biomass

Fuel CellsBasics of Fuel Cells

• A fuel cell is a device that chemically combines hydrogen and oxygen to produce electricity

• Two by-products are water and heat

• It is a developing resource

Fuel CellsCreating Energy

• Electricity is generated from fuel by combining the hydrogen and oxygen molecules found in the fuel

• A fuel cell consists of two electrodes, an anode and a cathode

• Electrodes are electrical conductors used in circuits

• The hydrogen molecules react at the anode and the oxygen reacts at the cathode

• The cells then release their by-products of water and heat

Fuel CellsCurrent Uses

• The idea of fuel cells is being tested all around the world to power vehicles and some appliances

• The United States leads the world in amount of fuel cell research

• Other countries include Japan, China, Germany, Republic of Korea, and Canada

• Fuel cell energy has been used to power cars and is being tested in appliances like vacuums, cell phones, etc.

Fuel Cells

Fuel CellsAdvantages and Disadvantages

Advantages Disadvantages• Quiet, durable, and highly efficient

• Some use expensive materials

• Reliable energy source • Storage of hydrogen is difficult

• Can be any size (large or small)

• Technology is not yet fully developed

• Eliminates pollution caused by fossil fuels

• Units are hand-made not by machines

Vocabulary1. Lunar Tides: The rise and fall of sea levels caused by the

gravitational pull of the moon

2. Tidal Barrage: A barrier that traps water at high tide, creating a tidal basin

3. Tidal Stream Generator: A turbine with underwater rotors that converts tidal power to energy

4. Biomass: A clean renewable energy from organic material

5. Electrodes: Electrical conductors used in the circuits of fuel cells

QuizQ. What is biomass energy?

A. Biomass is a clean renewable energy from organic material

Q. Where was the first tidal power station built?B. La Rance, France

Q. Name one advantage of fuel cells.A. Quiet, durable, high efficiency, reliable, can be any size,

eliminates pollution

Q. What are the two by-products of fuel cell energy?A. Water and Heat

QuizQ. Name a disadvantage to tidal power.

A. Expensive, hard to find location, bad for sea environment, disrupts tidal cycles, reduces ocean kinetic energy

Q. Why is biomass a good alternative for fossil fuels?B. It burns cleaner

Q. TRUE OR FALSE: Electrodes are electrical conductors used in Coal power plants.

C. False

Q. Who discovered that tides are caused by the gravitational pull of the moon?

A. Sir Isaac Newton