Energy Resources and Human Impact on the Environment

SPI 0707.7.7 Analyze and evaluate the impact of man’s use of earth’s land,

water, and atmospheric resources.

Energy and Fossil Fuels

•Most of the energy we use comes from nonrenewable fossil fuels. Fossil fuels were formed from the remains of plants and animals that lived long ago.

•All living things are made up of the element carbon. All fossil fuels are made of carbon, most of it in compounds called hydrocarbons.

•Fossil fuels may exist as solids, liquids, or gases.

Fossil FuelsCoal, oil and gas are called "fossil fuels" because

they have been formed from the organic remains ofprehistoric plants and animals.

How it works: Coal is crushed to a fine dust and burned.Oil and gas can be burned directly. Burn fuel->>heat water to ->steam turns _>turbines turn->electrical

power make steam turbines generators

• Petroleum, or oil, is a fossil fuel. It was formed more than 300 million years ago.

• Petroleum is commonly known as crude oil.

• Examples are gasoline, jet fuel, kerosene, diesel fuel, and fuel oil.

• More than 40% of the world’s energy comes from petroleum products.

• Crude oil is so valuable that it is called “black gold”.

• Natural gas provides around 20% of the world's consumption of energy.

• Like oil, it forms from the remains of microscopic sea organisms that settle on the ocean floor.

• Over millions of years, through chemical and physical changes, the remains become petroleum and natural gas.

• Rock forms above the rocks containing the fossil fuel and the fossil fuels move through permeable rock.

• To collect petroleum and gas, engineers must drill wells into the reservoir rock that holds them.

As well as being burned in power stations, natural gas is used by many people to heat their homes.

It is easy to transport along pipes, and gas power stations produce comparatively little pollution.

Coal • Coal is a hard, black colored rock-like substance. It is made up of

carbon, hydrogen, oxygen, nitrogen and varying amounts of sulphur.

• There are three main types of coal – anthracite, bituminous and lignite. Today, the precursor to coal—peat—is still found in many countries and is also used as an energy source.

• Coal is found in many of the lower 48 states of U.S. and throughout the rest of the world. Coal is mined out of the ground using various methods.

• The coal is then shipped by train and boats and even in pipelines.

• At the other end, the coal is used to fuel power plants and other factories.

• Coal provides around 28% of our energy, and Oil provides 40%

Advantages of Using Fossil Fuels

• Very large amounts of electricity can be generated in one place using coal, fairly cheaply.

• Transporting oil and gas to the power stations is easy.

• Gas-fired power stations are very efficient.

• A fossil-fuelled power station can be built almost anywhere, so long as you can get large quantities of fuel to it.

Disadvantages of Fossil Fuels• Fossil fuels take millions of

years to make. Once they are gone they are gone.

• Basically, the main drawback of fossil fuels is pollution. Burning any fossil fuel produces carbon dioxide, which contributes to the "greenhouse effect", warming the Earth.

• Oil spills like the most recent one in the Gulf destroy wildlife, the environment, and disrupt the ability of people to make a living.

Disadvantages of Fossil Fuels continued

• Coal mining causes pollution, destroys land and animal habitats and puts miners at risk due to possible mine collapse and personal health problems.

• Coal mining produces sulphur dioxide, a gas that contributes to acid precipitation. We can reduce this before releasing the waste gases into the atmosphere.

• Smog is produced when sunlight reacts with industrial pollutants and burning fuels.

ALTERNATIVE ENERGY RESOURCESRenewable energy sources including biomass,

hydropower, geothermal, wind, and solar provide 8% of the energy used in the United States. Most renewable energy goes to producing electricity.

What Is Renewable Energy?Renewable energy sources can be replenished. The Role of Renewable Energy Consumption in the

Nation's Energy Supply, 2010 The five renewable sources used most often are: • Biomass — including: • Water (hydropower) • Geothermal • Wind • Solar

wood and wood waste, municipal solid waste, landfill gas and biogas, ethanol biodiesel

Nuclear Power-Fission/Fusion• Nuclear energy is energy in the nucleus (core)

of an atom. Atoms are tiny particles that make up every object in the universe. There is enormous energy in the bonds that hold atoms together.

• Nuclear energy can be used to make electricity. But first the energy must be released. It can be released from atoms in two ways: nuclear fusion and nuclear fission.

Fission and Fusion compared• In nuclear fission, atoms

are split apart to form smaller atoms, releasing energy. Nuclear power plants use this energy to produce electricity.

• In nuclear fusion, energy is released when atoms are combined or fused together to form a larger atom. This is how the sun produces energy. Fusion is the subject of ongoing research, but it is not yet clear that it will ever be a commercially viable technology for electricity generation.

Advantages of Nuclear Power (Fission)

• Nuclear Power Plants Generate About One-Fifth of U.S. Electricity

• Nuclear power accounted for almost 20% of the total net electricity generated in the United States in 2010, about as much as the electricity used in California, Texas, and New York, the three States with the most people.

• Unlike fossil fuel-fired power plants, nuclear reactors do not produce air pollution or carbon dioxide while operating. However, the processes for mining and refining uranium ore and making reactor fuel require large amounts of energy.

Disadvantages of Fission

• The main environmental concerns for nuclear power are radioactive wastes such as uranium mill tailings, spent (used) reactor fuel, and other radioactive wastes. Wastes must be stored in an isolated place for thousands of years until they can’t hurt anyone.

• There is the potential for accidental release

of radiation into the environment.

• While fusion produces few dangerous wastes,but very high temperatures are required for the reaction to take place. No material can withstand such high temperatures so controlled fusion reactions have been limited to laboratory experiments.

Hydrogen Chemical Energy• Like electricity, hydrogen is a secondary

source of energy. It stores and carries energy produced from other resources (fossil fuels, water, and biomass).

• Hydrogen fuel cells make electricity. They are very efficient, but expensive to build. Small fuel cells can power electric cars. Large fuel cells can provide electricity in remote places with no power lines.

Fuel Cells Advantages

Portable fuel cells are being sold to provide longer power for laptop computers, cell phones, and military applications.

The only byproduct of fuel cells is water. They are also more efficient than internal

combustions engines are.

Fuel cells combine the best of batteries (quiet, no emissions) and internal combustion engines (easy refueling once the infrastructure is in place). 

They have a simple construction, so mass production costs would become extremely low. 

There has been a 10-fold increase in the power density of fuel-cell stacks and a 10-fold decrease in their cost within the past 5 years.

Disadvantages

Fuel cells are currently very expensive, but since they have a simple construction, mass production costs would become extremely low. 

Prototype fuel cells last only 1/5th as long as would be needed to make fuel cells cost-effective.  

They are energy losers because it costs more to produce hydrogen than is earned by using hydrogen in fuel cells: 

Electricity generated by fuel cells in cars costs thousands of dollars per kilowatt:  This would have to fall by a factor of 10 for fuel cells to become economically viable.

SOLAR ENERGY• When converted to thermal

(or heat) energy, solar energy can be used to:

• Heat water — for use in homes, buildings, or swimming pools

• Heat spaces — inside homes, greenhouses, and other buildings

• Heat fluids — to high temperatures to operate a turbine to generate electricity

• The three main types of solar thermal power systems are:

• Parabolic trough (the most common type of plant).

• Solar dish

• Solar power tower

Using solar energy produces no air or water pollution and no greenhouse gases, but does have some indirect impacts on the environment.

Advantages/Disadvantages of Solar EnergyAdvantages

• Solar energy is renewable

• Solar energy systems do not produce air pollutants or carbon-dioxide

• When located on buildings, they have minimal impact on the environment

Disadvantages• The amount of

sunlight that arrives at the Earth's surface is not constant. It varies depending on location, time of day, time of year, and weather conditions.

• Because the sun doesn't deliver that much energy to any one place at any one time, a large surface area is required to collect the energy at a useful rate.

• Solar cells and collectors are more expensive than other energy systems.

Wind PowerMade indirectly by solar energy through the uneven heating of air. Wind power is the use of a

windmill to drive an electric generator.

Advantages

•It is renewable

•It doesn’t cause pollution

•green energy

•Good availability

•Prices have decreased

•possibility for people to produce own electricity

•ability to save money

•Works in harmony with other methods

•can be a lifesaver in emergency situations

Disadvantages

•In some areas, the wind isn’t strong enough or frequent enough to create energy on a large scale.

•Wind is unpredictable

•wind energy is fluctuating

•cost effective? This is highly debatable

•aesthetics of wind turbines

•Wind turbines kill birds

•repair costs are usually expensive

Hydroelectric Energy

• supplies about 20% of the entire world’s electricity needs -About 88% of the total electricity that is generated from renewable energy sources.

• Hydroelectric energy is potential energy that is converted to kinetic energy through the forces of gravitation, which again comes from solar energy, driving the water cycle around. To answer the question, hydroelectric energy is the result of heat energy from the sun and the gravitational forces from the earth.

• By letting the water flow through turbines on their way to the sea, we can harness some of the kinetic energy of water to produce electricity. The flow and head determines the potential energy of a waterfall.

Advantages•Inexpensive to operate

•Causes little pollution

•Renewable

•Reduces our dependency on fossil fuels

Disadvantages•Expensive to build

•Only available near large bodies of water

•Destroys forests & wildlife habitats

•Disrupts migratory paths of salmon & steelhead

•Can decrease water quality and cause erosion

                                           

Source: The National Energy Education

BIOMASS

• Biomass is organic material made from plants and animals (microorganisms). Biomass contains stored energy from the sun.

• When burned, the chemical energy in biomass is released as heat.

• Biomass can be converted to other useable forms of energy, such as methane gas or transportation fuels, such as ethanol and biodiesel.

BIOMASS continued…

• Crops like corn and sugar cane can be fermented to produce ethanol. Biodiesel, another transportation fuel, can be produced from left-over food products like vegetable oils and animal fats.

• Biomass fuels provided about 4% of the energy used in the United States in 2010. Of this, about 46% was from wood and wood-derived biomass, 43% from biofuels (mainly ethanol), and about 11% from municipal waste.

Some farmers produce biogas in large tanks called "digesters" where

they put manure and bedding material from their barns.

Wood• The most common form of biomass is

wood. In the United States, wood and wood waste (bark, sawdust, wood chips, wood scrap, and paper mill residues) provide about 2% of the energy we use today.

Garbage, often called municipal solid waste (MSW), is the source of about 12% of the total biomass energy consumed in the United States

Landfill BiomassLandfills can be a source of energy. Anaerobic bacteria

that live in landfills decompose organic waste to produce a gas called biogas that contains methane.

Landfills can collect the methane gas, treat it, and then sell it as a commercial fuel.

Using Biomass for Energy Can Have Positive and Negative

Impacts

• Positive: Using wood, and charcoal made from wood, for heating and cooking can replace fossil fuels and may result in lower CO2 emissions.

• Positive: A waste-to-energy furnace burns at such high temperatures (1,800 to 2,000°F) that many complex chemicals naturally break down into simpler, less harmful compounds. This chemical change is a kind of built-in anti-pollution device.

• Negative: However, wood smoke contains harmful pollutants like carbon monoxide and particulate matter. Burning wood in an open fireplace is very inefficient and produces lots of air pollution.

• Negative: Plants that burn waste to make electricity must use technology to prevent harmful gases and particles from coming out of their smoke stacks.

For example, burning biomass may result in more or less air pollution depending on the type of biomass and the types of fuels or energy

sources that it replaces.

Gasohol

Advantages

• Domestically produced—reduces dependence upon foreign oil. Alcohol-based liquid fuel derived from plant biomass, primarily corn. Typically used in Flex Fuel vehicles as a blend of E85 [85% ethanol and 15% gasoline].

• Requires massive use of cropland to supply meaningful power. Has less energy per gallon than gasoline.

Disadvantages

• Requires massive use of cropland to supply meaningful power. Has less energy per gallon than gasoline.

• Ethanol and ethanol-gasoline mixtures burn cleaner and have higher octane than pure gasoline, but have higher "evaporative emissions" from fuel tanks and dispensing equipment. These evaporative emissions contribute to the formation of harmful, ground-level ozone and smog.

Geothermal Energy

• In some areas, groundwater is heated by magma, or melted rock.

• Geysers are natural vents that discharge steam into the air. The steam and hot water can escape through wells drilled into the rock. From these, geothermal power plants can harness this energy.

• “The Geysers” in California is the world’s largest geothermal plant and produces electricity for 1.7 million households!

Geothermal Power continued..

Disadvantages• There is

currently a very high cost of geothermal exploration and building of the energy generating plants.

• It can’t be built anywhere-there would have to be a source available.

Advantages• it is a very “green”

way to receive energy,

• Geothermal energy is very clean; it does not cause air, water, or soil pollution.

• It is a renewable source of energy. The hot water or steam is returned back into the Earth after being used.

Our World is a Gift-let’s take care of it!-it’s up to you!

THE END……..