Presentation on theme: "Non-Renewable Energy Resources: How do dead things power our lives?"— Presentation transcript:
1 Non-Renewable Energy Resources: How do dead things power our lives? Life requires energy – it is stored, transferred, and convertedUltimate source of energy for life – the SunFor humans, our source of energy is foodFuel – any substance that can be used for energyFuel is never 100% efficient – only 5-20% of what is received is actually usedDuring conversions, some energy is lost - some is converted into heat, light, or sound energyHuman need for energy has changed through timeHunter-Gatherers – woodIndustrial Revolution – oil, coalContemporary – use many types of energy sources
2 Evaluating Energy Resources The types we use determine our quality of life and the amount of harmful environmental effectsQuestions to ask ourselves:How much of the energy source will be available in the future?What is this source’s net energy yield?How much will it cost to develop, phase in, and use this resource?How much will extracting, transporting, and using the energy resource affect the environment?What will using this energy source do to help sustain Earth?
3 Net Energy is .. It takes energy to get energy the total useful energy available from the resource over its lifetimeminusthe amount of energy used, lost, and wasted in finding, processing, concentrating, and transporting it to uses.It takes energy to get energy
4 Non-Renewable vs. Renewable Non-renewable – resources that cannot regenerate quickly (takes thousands or millions of years)Renewable – resources that regenerate quickly (within decades)
5 Nuclear Energy – What is It? Nuclear reactors produce energy by splitting atoms apart; a star releases energy by joining atoms. Atoms of uranium split, the energy released heats water to produce steam drives turbines to produce electricity.
6 Nuclear Energy – ProsNuclear power plants don’t emit air pollutants (when operated properly)Water pollution (thermal pollution) and disruption of land are low to moderateSafety measures reduce the likelihood of a catastrophic accident
7 Nuclear Energy - Cons Harmful radiation leaks into the environment Chernobyl ( ): reactor explosions in the Ukraine killed 3,576 people (officially, but other estimates say 32,000) and over 500,000 were exposed radioactivity causing cancer, tumors, eye cataract, and genetic mutationsThree-Mile Island ( ): plant in Pennsylvania lost is coolant water (mechanical and human errors); no known injuries/deaths were reported, but some studies show increased cancer rates in the area from radioactive materials leaking into the atmosphereRadioactive WasteHigh-level waste must be stored for 10, ,000 yearsLow-level waste must be stored for 100s of years (dumped in the ocean during the 1970s)After years, the nuclear reactor becomes too radioactive and must be dismantled or shielded with a barrierUsed to be inexpensive, but maintaining the building and storing wastes is now expensive
8 Fossil Fuels – What are they? Fuel formed hundreds of millions of years ago from the remains of dead plants and animalsMade of hydrocarbonsWhen combined with oxygen light and heat energy are released (combustion)Types: Coal, Natural Gas, Petroleum/Oil
9 CoalPlant remains converted by heat and pressure into a solid rock over millions of yearsHas stages of development that concentrates the coal and the energy it producesPeat – low amount of carbon / least amount of energy (not true “coal”)Lignite – 40% carbon, must be mined from below groundBituminous Coal – 85% carbon, deep in Earth’s crust, most abundant type in the United StatesAnthracite Coal – 95% carbon; deepest in the ground; has the least amount of water and impurities and has the greatest amount of energy
10 Coal – Pros and Cons Pros Cons Most abundant fossil fuel (should last at least 220 years at the current rate of use)High net energy yield (25-28%)ConsCoal mining is dangerous (accidents, black lung disease) and harmful to the environment (land and water pollution)Dirtiest to burn and release many air pollutants (carbon monoxide, carbon dioxide, and radioactive elements)Threat to human health (respiratory diseases from air pollutants) and results in property damages
11 Natural GasMixture of mostly gaseous hydrocarbons (methane is the primary component)Forms from the remains of plankton, plants, and animals living in shallow water millions of years ago
12 Natural Gas – Pros and Cons Cheaper than oilReserves are expected to last yearsCan be transported easilyHas a high energy yield (4.9%)Produces less air pollution than any other fossil fuelExtraction damages the environment lessCan be used to power vehicles and highly efficient fuel cellsConsToxic sulfur can be released into the airIn order to ship it over the ocean, it has to be converted to liquid, which is expensive and dangerous (explosions)Leaks from pipelines, tanks, and distribution facilities increases the amount of methane (greenhouse gas) in the atmosphere
13 Petroleum/Oil Forms the same as oil Can “gush” out of the ground or needs to be pumped to the surface with drilled wellsRaw or crude oil is refined into many different products, many of which play a crucial role in our lives:Gasoline, jet fuels, diesel fuel, fuel oil, grease (Vaseline), asphalt, nylon, polyester, plastics, styrofoam
14 Petroleum/Oil – Pros and Cons Relatively cheapEasily transported within and between countriesHigh net energy yield (4.7%) when easily accessibleConsReserves may be depleted with 85 yearsOil-drilling process cases damage to the environment which increases erosionOil spills contaminate soil and/or waterBurning fuel oil releases carbon dioxide which leads to global warming and other air pollutants that harm people, crops, trees, fish, and other plants/animals
15 Should we reduce our dependence on fossil fuels? Used to make fuels, plasticsFossil fuels provide numerous productsThey are easy to use and relatively cheapRich in hydrocarbon energyShould we reduce our dependence on fossil fuels?Remains of organismsRequires combustion for energyTakes millions of yearsSource depletingSpills contaminate the ecosystemFossil fuels are non-renewableThey pollute the environment