ENVIRON 102 Chapter 16: Chapter 16 (textbook) All
10 May 2018
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Chapter 16 Renewable Energy and Energy Conservation (all)
16.1 Renewable Energy Overview
The Transition to Renewable Energy: Can we reduce demand for limited energy sources and diminish the
environmental impacts of human energy use?
Renewable energy (6% of global energy) = energy that is constantly replenished
Primary challenge for renewable energy is that they diffuse and are intermittent
o Ex: solar energy is spread out across the Earth’s surface and is not that concentrated
o So we have to capture their diffuse energy flows and convert into more concentrated forms
Associated pollution and emissions are relatively low
Challenges: There are four general categories of challenges to the widespread use of renewable energy.
Unfamiliar technologies
o Technology for renewable energy is still in early developmental stages
o Associated uncertainties and risks = scarce investment capital = high interest rates = high
development costs
Economies of scale
o New technology = small scale of production = production costs are high
o Chicken or the egg question for solar panels
o Production costs will fall as demand for such technologies improve
Externalized costs
o Price of energy doesn’t reflect externalities such as the health problems associated with
emissions
Limited consumer knowledge and understanding
o Consumers don’t know how to interpret energy usage figures when buying automobiles
o Limited knowledge about source of electricity
16.2 Hydropower
Hydropower: energy of water moving under the force of gravity (57% of renewable energy)
o Produces hydroelectric power – electricity generated by using the kinetic energy of moving
water to turn a turbine
Sources and Supplies: Hydropower facilities provide a significant amount of the world’s renewable
energy.
Hydropower is renewable
o Water is replenished in the hydrologic cycle (which is powered by the energy from the Sun)
Generates electricity or hydroelectric power
Impoundment hydroelectric plant
o Impound (or store) water behind a dam
o When water is released from dam, the water flows downhill through a turbine, spinning the
turbine and generating electricity
Run-of-river hydroelectric plant
o Portion of river’s water is diverted into series of pipes that lead to a powerhouse
o Force of flowing water spins a turbine, generating electricity
o Usually less costly to build and operate and less disruptive to aquatic ecosystems
o Dependent on sustained flow of river water so are not practical for rivers with high
variability
Norway obtains 99% of electricity from hydropower
o But only generates /3 of Canada’s electricity
Advantages and Disadvantages of Hydropower: Hydropower emits few pollutants or greenhouse gases but
has negative impacts on river and floodplain ecosystems.
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Advantages of Hydropower
Disadvantages of Hydropower
Does not rely on fossil fuels but derives
energy from hydrologic cycle
Criticized or the effects on the environment
and human communities
Relatively inexpensive after infrastructure is
built
Displacement of people (Ex: Three Gorges
Dam in China)
Domestic
Negative impact on ecosystems
Flexibility for meeting fluctuating power
demands
Diminish downstream flows and alter
natural seasonal variation in flows (ex:
floods)
Flood storage and storage for water for
cities/agriculture
Submersion of vegetation may release
methane
Future Development: Growth in hydropower production is likely to slow in the near future.
Require large amounts of up-front capital for investment
Concern for migratory fish
Approach to hydropower with fewer environmental and social drawbacks – hydroelectric-
generating facilities to existing dams
16.3 Wind Power
Wind power: use of windmills to power devices that pump water, mill grain, and saw wood
Sources and Supplies: The kinetic energy of moving air can be converted into electricity.
Energy that drives wind is from sun
o Winds form from uneven heating from sun, which produced high and low pressure
Wind turbines: devices that transform kinetic energy of moving air into electricity
o Each turbine can power 1,400 houses
o Wind farms: clusters of wind turbines
Denmark relies on wind power the most
Advantages and Disadvantages of Wind Power: Wind power is economical but intermittent.
Advantages of Wind Power
Disadvantages of Wind Power
Requires no fuel to generate electricity
Kills birds and bats
No pollution or waste
Are located in migratory locations
Domestic
Aesthetics (the view?)
Not subject to supply disruptions because
wind farms are spread out
Less reliable because wind is more
intermittent
Little fluctuation in electricity prices (as
compared to natural gas)
Areas with the greatest wind power are far
away from urban centers
Future Development: Wind power has become cost competitive with other sources of electricity.
Last 25 years, cost of generating electricity using wind power declined by more than 90%
Competitive with coal but less expensive than natural has or nuclear power
16.4 Solar Energy
Solar energy: radiant energy of the sun
Sources and Supplies: Solar energy is now widely used to heat and light homes and other buildings.
Passive solar technologies: energy of sunlight without relying on electrical or mechanical devices
(ex: pumps or fans)
o Ex: orienting buildings so that they receive maximum sunlight and using building materials
that absorb sunlight to keep interior spaces warm
Active solar technologies: mechanical devices to heat water and building or electrical devices to
heat water and buildings or electrical devices to generate electricity
o Ex: rooftop solar panels
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Chapter 16 renewable energy and energy conservation (all) Renewable energy (6% of global energy) = energy that is constantly replenished. Primary challenge for renewable energy is that they diffuse and are intermittent: ex: solar energy is spread out across the earth"s surface and is not that concentrated. Associated pollution and emissions are relatively low: so we have to capture their diffuse energy flows and convert into more concentrated forms. Challenges: there are four general categories of challenges to the widespread use of renewable energy. Unfamiliar technologies: technology for renewable energy is still in early developmental stages, associated uncertainties and risks = scarce investment capital = high interest rates = high development costs. Externalized costs: production costs will fall as demand for such technologies improve. Sources and supplies: hydropower facilities provide a significant amount of the world"s renewable. Hydropower: energy of water moving under the force of gravity (57% of renewable energy: limited knowledge about source of electricity.
