Energy Resources

1. Energy Resources Renewable and Nonrenewable

2. Electricity • Electricity is a form of energy • We use electricity to power most modern devices • How do we create electricity?

3. Electric generator

4. Energy Usage • 1 watt = 1 joule 1 second

5. A typical coal burning power plant can produce 500 megawatts of power • A nuclear reactor plant can produce 1,500 megawatts • And a hydroelectric dam can produce 10,000 megawatts

6. Energy sources • Nonrenewable resources are ones that have a limited supply on earth • These would be the fossil fuels • Coal • Petroleum • Natural gas

8. Coal • Coal is a solid and composed of many types of hydrocarbon chains and rings • It is the most abundant of the nonrenewable resources

9. Problems • Coal is hazardous to mine out • Human health hazards • Environmental hazards • Coal also contains many contaminants • Sulfur • Heavy metals • Radioactive elements

10. Burning coal accounts for 50% of the sulfur dioxide released into the atmosphere and 30% of the nitrogen oxides

11. Purification of Coal • Many of the contaminants can be seperated out of coal by “floating” the coal • This process involves pulverizing the coal and placing it in a solution which allows the coal to float while the contaminants sink to the bottom

12. Floating removes 90% of iron sulfide but more sulfur remains in the coal • This remaining sulfur is removed during the burning process by scrubbers

13. These two methods have reduced the amount of sulfur dioxide released by 30% • But this comes at a cost of 3% efficiency in the energy produced by burning coal

14. Improvements • Suspended burning of coal improves the output to 42% • Also adding limestone will remove most of the sulfur without the use of scrubbers

15. Petroleum • By far the most used fossil fuel in the US • Why? • Because it’s a liquid • Easy to extract • Easy to transport • Petroleum also has less sulfur than coal

16. Petroleum contains all of the hydrocarbons necessary for gasoline, diesel fuel, jet fuel, motor oil, tar, and natural gas • Fractional distillation can separate out each of these hydrocarbons

17. U.S. Consumption • We use 17 million barrels a day • Of this 1 million barrels goes to make useful materials like organic compounds and polymers

18. Natural Gas • Natural gas – equal in abundance to petroleum • It is the purest of the fossil fuels

19. Burning Natural Gas • The combustion of natural gas releases very small quantities of sulfur dioxide (negligible) • Also it burns at a lower temperature than coal so less nitrogen oxides are produced as well • Also carbon dioxide is reduced by 50% as well

20. Disadvantages • Since it is a gas it is more difficult to store and takes up more space • It is also difficult to transport over large distances

21. Energy Production • Natural gas does produce more electricity than the other two fossil fuels • Gas turbine – hot gases from the combustion of natural gas can drive a paddlewheel for a gas turbine • This with a steam turbine increases energy output to 47%

22. Methane and propane are the two most commonly distributed products • Methane is lighter than air and thus easily distributed within a city through pipes • Leaks are usually dissipated in the atmosphere • Propane – heavier than air, it can be pressurized into a liquid and stored in tanks • Useful when not connected to a city supply

23. Nuclear energy • Nuclear fission – breaking apart a large nucleus into smaller fragments • Nuclear fusion – combining two small nuclei into a larger one

24. Fission • Today 20% of the electricity used in the US is from nuclear reactors • Fission releases no harmful gases or heavy metals, but there is radioactive waste associated with it

25. Radioactive waste must be stored for centuries before it is safe again • Where do we put this waste?

26. Accidents • Nuclear power has had a few problems since the 1950s • Three Mile Island (partial meltdown in 1979) • Chernobyl (1986) • New reactors are being built that use smaller cores and passive systems to control a melt down

27. Chernobyl

28. Years after the accident: • Containment building built but hastily so it needs remodeling • Several tons of radioactive dust and core material still present in reactor 4 • Reactor 2 shut down due to fire in 1991 • Reactor 1 shut down in 1996 • Reactor 3 finally shut down in 2000

29. Health related issues: • 10,000 cases of Thyroid cancer thus far and a total of 50,000 expected • 10,000 deformities • 5,000 infant deaths • Hundreds of thousands works sick after dealing with the aftermath, tens of thousands dead

30. Fusion • This process takes deuterium and tritium and creates helium and fast moving neutrons • These neutrons provide the power for either making steam or hot ionized gas

31. Benefits • No green house gases are created and released into the environment • No heavy metal contaminants are released as well • Less radioactive waste is made compared to fission

32. Problems • While these reactions have already been done. The energy required to fuse nuclei is much greater than the energy released. • Also the cost to produce a fusion reactor will take decades to recoup so it is not an attractive idea for profit

33. Most of the energy used by the world comes from non renewable sources • (approx 1/3 is renewable at this time)

34. Renewable resources • Renewable resources are resources in which there is a virtually limitless amount • Types • Hydroelectric • Geothermal • Solar • Wind

35. Hydroelectric • Water is used to turn a turbine which creates electricity • This is clean energy creating no green house gases or other pollutants • The kinetic energy of the water can be converted to electricity at 95% efficiency

37. Ocean Thermal Energy Conversion • Utilizes the difference between surface water temperatures and deep water temp to generate energy

38. Disadvantages • Requires blocking a natural river (hydroelectric) • This can change the ecosystem of the aquatic life (both)

39. Geothermal • Utilizes hot water geysers or steam geysers • The steam geysers can directly drive turbines to make electricity • Hot water can be used to boil a secondary liquid or used to directly heat a building

40. Biomass • Alcohol in gasoline • Directly using biomass • possible to link solid waste disposal to energy generation (80% dry weight is combustible) • Biodiesel • diesel fuel derived solely from natural products like animal fat and vegetable oils • Burns cleaner than diesel with about 50% less CO2 released

41. Solar power • The sun is an excellent source of heat • Solar cells can be used to heat air or water in pipes

43. Solar thermal electric generation uses the sun to create electricity • Refractive mirrors can be arranged to focus the sun’s rays into a small area • These rays heat a solid (sodium nitrate salt) to 2200°C. This melts the salt which is then used to either heat water to create steam or stored for later use (lasts up to a week in insulated tanks)

46. Problems • The efficiency for converting solar power is pretty low and the cost of the mirrors or cells is quite expensive right now • It would take ½ of the state of Nevada being covered in solar cells to provide enough electricity to supply the US

47. Wind • Windmills have been used on the south plains for generations • We can now use it to directly create electricity

48. Increased efficiency

50. Problems • Need an area of moderate wind • High winds will break the blades of the turbine • Low winds will not create enough electricity • Large amounts of them are needed to power a city the size of Lubbock (thousands) • For personal use a turbine will cost around $30,000