ENERGY RESOURCES

Lesson 5

Canadians are some of the highest consumers of energy in the world. Currently, 89% of energy resources used in Canada are non-renewable.

As the world’s population grows we need to find more efficient energy-transforming technologies. Original sources of energy are called energy resources.

A raw material, obtained from nature, that can be used to do work; also called an energy source. Renewable Resource

An energy resource the renews itself in a normal human lifetime

Non-Renewable An energy resource that does not renew itself in a

normal human lifetime.

NON-RENEWABLE RESOURCES

FOSSIL FUELS Fossil fuels are convenient and for the

time being readily available but there are many disadvantages.

It is costly to remove from the ground and to deliver to the user. When burned the products produce pollutants that contribute to climate change.

FOSSIL FUELS Unspent fuel also contaminates the

environment when it is leaked or spilled. Of the natural gasses, Natural gas burns the cleanest and has the least amount of environmental impact.

FOSSIL FUELS1. the fuel is burned to boil

water to make steam2. the steam makes a

turbine spin3. the spinning turbine

turns a generator which produces electricity

4. the electricity goes to the transformers to produce the correct voltage

NUCLEAR Nuclear reactors use uranium in a

process called nuclear fission. The nucleus of an atom is split and energy is released. If enough nuclei are split water can be heated to produce steam, this generates electricity in a very similar manner to that of fossil fuels.

CANDU reactors are Canadian built and designed reactors that are much safer than other reactors as it is almost impossible for them to have a melt-down.

Nuclear power is very expensive to set up and the nuclear waste is also a major problem. However, they produce very little emissions and can be built where they are needed as long as there is a water source.

NUCLEAR ENERGY In a nuclear reactor, atoms of a heavy

element, usually uranium, are split in a chain reaction. This splitting, called nuclear fission, releases an enormous amount of energy.

The nuclear fission of just 1 kg of uranium is equivalent to burning about 50 000 kg of coal.

RENEWABLE RESOURCES

SOLAR ENERGY Solar energy from the sun (radiant), can

be used in solar cells, or photovoltaic cells. These devices transform light energy directly into electrical energy.

Solar energy can also be used to heat buildings directly.

PASSIVE SOLAR HEATING takes advantage of the Sun’s

energy at all times of the year. This includes eaves that overhang the windows to block sunlight in the summer and allow light in, in the winter.

ACTIVE SOLAR HEATING uses solar collectors to absorb the

Sun’s energy and converts it into thermal energy that can be used elsewhere in the structure. This is much more expensive than the passive method.

SOLAR Solar energy is abundant, non-polluting,

and available almost anywhere. The set up can be expensive but they usually require little maintenance.

SOME CITIES ARE TAKING POWER GENERATION SERIOUSLY One of the world’s largest solar energy

projects includes solar farms in Sarnia and Sault Ste. Marie and aims to produce enough electricity for about 9000 homes

HYDRAULIC ENERGY Hydraulic energy uses gravitational

potential energy generated by water to turn turbines connected to generators. This is an indirect source of the Sun’s radiant energy as the water cycle is powered by the sun.

HYDRAULIC ENERGY This is an indirect source of the Sun’s

radiant energy as the water cycle is powered by the sun.

HYDRAULIC ENERGY This method electricity generation does

not produce pollution but it does affect the ecology of the river where it is dammed.

The electricity must also normally be transmitted long distances which reduces its efficiency.

SIDE NOTE:60 % of Canada’s electricity is

generated by hydroelectric

WIND ENERGY Wind energy is also generated indirectly

by the Sun’s radiant energy. The kinetic wind energy is used to

turn rotors on turbines attached to generators. Wind mills require large amounts steady wind all year long. They do not produce any pollution but the power generation is dependent on if there is wind and the turbines are noisy and known to kill migrating birds.

WIND ENERGY Wind energy currently provides about 1

percent of Ontario’s electricity, but it is one of the fastest-growing energy sources in the world.

TIDAL ENERGY Tidal energy is a potential energy in

regions that are affected by ocean tides. Tides are produced by the

gravitational pull of the moon. To harness the energy a dam must be

built across the mouth of a river that enters the ocean. When the tide comes in gates are opened and the water pours in and turns turbines

When the tides goes out the gates are opened again and once again the turbines are used to produce electrical energy.

This method does not produce pollution but the energy generation is dependent on the tides, the dams can affect the ecology and because the turbines must be able to spin two ways they require a different turbine technology.

 

BIOMASS ENERGY Biomass energy is a chemical energy

stored in plants and animal waste. This energy comes indirectly from the sun to

grow the plants. This energy source can be as simple as a

wood stove to a methane capturing facility which then burns the fuel in the same manner as a fossil fuel power plant. Although this method can be renewable if trees are replanted and it also reuses materials but it does produce pollution.

BIOMASS Examples of biomass include wood, peat, straw,

nut shells, sewage, and corn husks Organic waste decomposes to produce a

gas called methane. The methane gas can be burned to boil water to make steam. The most common biomass material used today is wood waste from lumber and from pulp and paper industries.

GEOTHERMAL ENERGY Geothermal energy is thermal energy

or heat taken from the beneath the Earth’s surface. The source of this heat is radioactive decay. On average every 1km in depth results in a 25 ° C increase in temperature. Obviously volcanic areas are more suitable for this method of energy generation.

NUCLEAR FUSION Nuclear fusion is the process in which

the nuclei of the atoms of light elements join together at extremely high temperatures and densities to become larger nuclei. This is the energy source at in the Sun and stars.

NUCLEAR FUSION Since hydrogen is one of the most

abundant atoms we have a limitless fuel source that produces much less nuclear waste than nuclear fission.

The problem is that temperatures of a few million degrees are needed to start the reaction and then the pressure must be extreme in order for the reaction to continue.

This makes this energy source a very distant possibility.

HYDROGEN FUEL CELLS In a fuel cell, the chemical potential

energy of the fuel, is changed directly into electrical energy.

The hydrogen combines chemically with oxygen in the presence of a catalyst. The result is the production of water and electric current.

FUEL CELLS

The fuel cell is very efficient because it transforms the energy directly from chemical energy into electrical energy.

It also operates at a relatively low temperature, thus emitting very few pollutants. I

t is also quiet and easy to maintain. The major problem is that energy is

needed to obtain the hydrogen from water.

SOME STATS

SOME STATS

SOME STATS

QUESTIONS Write the energy transformation

equation for each of the following resources used to produce electrical energy. Which is the most efficient? Each transformation will lose some energy to heat.

A) Hydraulic, B) The Sun, C) Biomass, D) Nuclear fission, E) Wind, F) Geothermal, G) Fossil Fuels.

COMPARING METHODS OF GENERATING ELECTRICITY Source Advantages Disadvantages

Fossil Fuels

- Fossil fuel generating stations can quickly adjust to changes in demand

- The technology for using these fuels is already in place

- The burning of fossil fuels releases pollutants into the atmosphere and directly contributes to global warming.

- Mining coal is hazardous to the workings and damages the environment

COMPARING METHODS OF GENERATING ELECTRICITY Source Advantages Disadvantages

Nuclear - Nuclear power is inexpensive to produce

- Produces enormous amounts of energy from very little fuel.

- Waste is poisonous and radioactive and needs to be stored very carefully for hundreds or thousands of years

- Nuclear plants are very costly to construct and maintain.

COMPARING METHODS OF GENERATING ELECTRICITY Source Advantages Disadvantages

Hydroelectric

- Large generating stations produce electricity inexpensively

- Reservoirs may be used for flood control, irrigation, drinking water, and recreation

- Small scale hydroelectric plants using the local rivers can be practical for some communities

- There is a huge environmental impact when the dam is constructed, including flooding large areas of land, disruption or destruction of wildlife and fish habitat and migration routes, and displacement of Aboriginal communities.

- Hydroelectric stations are very expensive to build

COMPARING METHODS OF GENERATING ELECTRICITY

Source Advantages Disadvantages

Sunlight - Solar cell energy is a convenient source of energy for small appliances, such as calculator’s Solar energy is useful in remote areas.

- Solar cell efficiency is low, so many photoelectric cells have to be used, which takes up large areas of land.

- Solar energy is the most expensive energy source at present.

COMPARING METHODS OF GENERATING ELECTRICITY Source Advantages Disadvantages

Tides - Once tidal generating stations are built, tidal energy is very inexpensive.

- Tides are more predictable than wind or sunlight

- The environmental impact of marine life in area can be significant, due to changes in water level and water quality.

- Tidal energy is suitable for few areas as it requires very high tides.

COMPARING METHODS OF GENERATING ELECTRICITY Source Advantages Disadvantages

Wind - Wind energy production does not produce greenhouse gases that contribute to global warming.

- Farming and grazing can continue on land where wind turbines are located.

- The wind does not always blow or remain constant.

- Wind turbines can present barriers to bird movement, cause bird fatalities due to collisions with turbine blades, and can disturb breeding, wintering, and staging sites.