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Child and Family Studies
ENSC 1005
Heather Kaye

Monday December 3, 2012 Energy Solar Energy
- 99% of energy that heats the Earth and our homes comes from the sun
- Produced from the nuclear fusion of hydrogen atoms
- Solar energy also produces indirect forms of renewable energy: wind, falling and flowing water (hydropower), and biomass (result of photosynthesis) Commercial Energy (energy sold in the marketplace)
- makes up remaining 1% of energy we use
- most comes from extracting and burning non-renewable fossil fuels: oil, coal, and natural gas
- 84% comes from non-renewable energy resources (78% from fossil fuels and 6% from nuclear power) and 16% comes from renewable energy resources (biomass, hydropower, geothermal, wind and direct solar energy)
 - See FIG. 17.3, p.374 - Future direction of energy use in U.S. will impact Canadians from an economic and an environmental perspective Evaluating Alternative Energy Resources
- important questions to answer for each energy alternative 1) How much of the resource is likely to be available in the near future (15-25 years) and the long term (25-50) years 2) What is the net energy yield for the resource? 3) How much money to develop, phase in and use?
4) How will extracting, transporting and using the energy resource affect the environment, human health, and Earth’s climate? Should the harmful costs be included in the market price of the resource? 5) How will dependence on the resource affect national and global economic and military security? 6) What government research and development subsidies and tax breaks will be used to help develop the resource? Net Energy – total amount of useful energy available over lifetime of resources minus the amount of energy needed to make it available for use - Can also be looked at as a ratio of useful energy: useful energy to produce it à the higher the ratio, the greater the net energy, if ration < 1 there is net energy loss (Fig. 17-8 pg. 374) Non-renewable Resources
 1) Oil – also called petroleum
- a thick liquid consisting of chains of hydrocarbons with nitrogen and Sulphur
- fossil fuel formed as a result of dead organic material buried deep in sediments under high pressure and heat that collected in porous limestone or sandstone covered by a cap of shale or silt to keep it from escaping - Extracted by drilling
 - Canada has the worlds second largest crude oil reserves
 - Burning it produces air pollution and releases the greenhouse gas CO2
 - advantages and disadvantages see FIG. 17-15 pg. 381 2) Natural Gas – liquid consisting mainly of the hydrocarbon methane
- fossil fuel that lies above reservoirs of crude oil (gas is less dense then oil)
- extracted and transported by pipelines
- releases CO2 when burned
- advantages and disadvantages Fig. 17-22 pg. 385 3) Coal – solid fossil fuel consisting of mostly carbon with small amounts of Sulphur and trace amounts of mercury and radioactive material
- extracted by surface and underground mining
- releases CO2 and SO2 (Sulphur dioxide), radioactive particles and toxic mercury when burned
- advantages and disadvantages Fig. 17- 24 pg. 387 4) Nuclear Energy – solid uranium undergoes controlled nuclear fission in heavy water (to slow down neutrons so a nuclear chain reaction can be sustained) producing extreme heat that heats water to produce stream that turns turbines that turns a generator to produce electricity - Causes thermal water pollution when water is recycled and can have extreme environmental impact if there is a major accident
 - Highly radioactive wastes must be safely stored for thousands of years - Advantages and disadvantages Fig. 17-30 pg. 393 Energy Efficiency
- 84% of energy used in Canada is wasted (41% due to the 2 nd law of thermodynamics and 43% unnecessarily wasted because of poorly insulated buildings, fuel-wasting motor vehicles, furnaces) - Easiest, fastest and cheapest method to get more energy with least environmental impact:
1) eliminate unnecessary waste by making lifestyle changes that reduce energy consumption, and
2) Increase efficiency of energy conversion devices (get same amount of work out of a device with less energy input) (Fig. 18-4, pg. 404 & Fig. 18-5, pg. 405) - Energy efficient models cost more initially but save money in long run by having a lower life cycle cost (initial cost + lifetime operating costs) Reducing Energy Waste
 1) Make non-renewable fossil fuels last longer 2) Give more time to phase in renewable energy resources
 3) Decrease dependency on oil imports 4) Reduce need for military intervention in oil-rich but politically unstable Middle East
 5) Reduce local and global pollution and environmental damage
 6) Improves local economy by reducing flow of money out to pay for energy
 7) Provides more jobs
 8) Improves competitiveness in international marketplace Increasing Energy Efficiency 
 1) Using waste heat – slow the rate at which waste heat flows into the environment when high quality energy is degraded 
 - E.g. - Insulate homes and eliminate air leaks)
 in office buildings and stores collect waste heat from lights and machines and distribute it to reduce heating bills in cold weather and vent it outdoors in hot weather to reduce cooling costs - In industrial plants waste heat can be used to produce electricity and distribute it through insulated pipes to heat nearby buildings 2) Save energy in industry – 45% of all energy is used world-wide occurs in industry
 - E.g.. Cogeneration – production of 2 useful forms of energy (such as steam and electricity) from the same fuel source (heat from industrial boilers could produce steam to turn turbines to turn generators to produce electricity and plant either uses electricity or sells it and saves energy and money) 
- Replacing energy wasting electric motors (run at full speed) with adjustable speed drives
- switching to high efficient lighting/turning off lighting when not required
 - Recycle, reuse, making products that last longer saves energy compared to using virgin resources 3) Saving energy in producing electricity
 - E.g. – Companies trying to reduce demand for el
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