1 ALTERNATE ENERGY SOURCES

2 Solar Energy Definition Of Solar EnergyThis is energy received from the sun by the Earth in the last 100 years Hydroelectric power Wind power PG & E MW by 1990 SCE MW by 1990 Wood Ocean currents Passive and direct solar power

3 Solar Energy Advantages of Solar PowerSolar energy received by the Earth is enormous 17.7 x 1016 watts 100,000 x world electrical output Infinite supply Constant supply No pollution No boycotts Biologically compatible

4 Solar Energy Passive Solar Power Space heating Water heating

5 Solar Energy Direct Solar - Converts Sunlight to ElectricityThis is very expensive Modern 1000 MW plant would require 42 sq. km. or 16.2 sq. miles 10,000 MW input Surface receives watts/cm2 1010 watts/0.024 watts/cm2) = 42 sq. km. A future approach might involve satellite receivers microwaving the energy to Earth

6 Water Power History and PotentialLarge scale generation and transmission of water power started around 1900 Present production is 45,000 MW Ultimate maximum based on stream flow is 161,000 MW It appears that some used potential may help compensate for declining fossil fuels

7 Water Power The Problems of Hydroelectric PowerDams have a large impact on the environment Most acceptable hydro sites are already developed Hydroelectric power only supplies a small percent of the nations power

8 Tidal Power Same Basic Principle as Hydroelectric PowerTidal energy can be exploited in two ways: By building semi-permeable undersea tidal turbines across estuaries with a high tidal range. By harnessing offshore tidal streams

9 Tidal Power How it works:Water flow as basin fills or empties drives turbines Similar to a wind turbine, but goes in both directions Requires a daily tidal range of 5-7 meters (~15-21 feet) to be practical Characterized by low capacity factors, usually in the range of 20-35%.

10 Tidal Power Locations 240 MW facility has operated in France since 1966 20 MW in Canada since 1984 A number of stations in China since 1977, totaling 5 MW

11 List of World Main Tidal Power StationsCountry Power Station Tidal Loss (m) Capacity (MW) Operated Since France Langce 8.5 240 1966 Canada Andeboriece 7.1 19.1 1984 Former Soviet Union Gicelaya 3.9 0.4 1968 China Jiangxia 5.1 3.2 1980 Baishakou 2.4 0.64 1978 Xingfuyang 4.5 1.28 1989 Yuepu 3.6 0.15 1971 Haishan 4.9 1975 Shashan 0.04 1961 Liuhe 2.1 1976 Guozishan 2.5 1977

12 Tidal Power La Rance, France - world's first tidal power plantAverage tidal range 27 feet Dam encloses 8.5 sq. miles Capacity is 320,000 KW

13 Tidal Power Low Production but also Low Environmental ImpactNo noxious waste No consumption of resources Minimum disturbance to scenery

14 Geothermal Power Source of the Energy Conduction to the surfaceConvection by volcanoes and hot springs

15 Geothermal Power Two Methods of Recovery Dry Steam Geothermal FieldsSteam rises to the surface and is used directly to drive a turbine Geysers, California is an example Produced 2000MW by 1986 Serves 12 cities & 2 million people around Sonoma County Ultimate possible is 2500 MW This type is rare

16 Geothermal Power Two Methods of Recovery (continued)Wet Steam Geothermal Power Steam and water come to the surface and must be separated This type is found and used in New Zealand, Japan, Mexico, Russia, & Iceland Water may be used for conventional heating before disposal Disposal method depends on salinity Pour it into a river Pipe it to the ocean for disposal Reinject it

17 Geothermal Power Recovery from Non-thermal AreasThis is more challenging and has not yet been accomplished Drill 2 adjacent holes Pump cold water into one Recover steam from the other

18 Atomic Fusion Possibility was first recognized by Hans Bethe Nobel Prize) Concept is to harness the energy of the sun by fusing 1D2 into 2He3 or 2He4 This has already been done in the form of the hydrogen bomb

19 Atomic Fusion DefinitionsProton – a positively charged subatomic particle Neutron – a negatively charged subatomic particle

20 Atomic Fusion DefinitionsIsotope – atom that exhibits variation in its mass number Mass number – sum of the neutrons plus the protons in an atom Atomic number – # of protons found in the nucleus Atomic weight – average of the atomic masses of all the element's isotopes

21 Atomic Fusion DefinitionsFission – the act or process of splitting into parts Fusion – a nuclear reaction in which nuclei combine to form more massive nuclei with the simultaneous release of energy

22 Atomic Fusion The 3 Isotopes of Hydrogen Hydrogen 1H1 Deuterium 1D2Tritium 1T3

23 Atomic Fusion The Reactions1D2 + 1D2 --> 2He3 + n Mev 106 electron volts) This produces a stable end product 1D2 + 1D2 --> 1T3 + H Mev 1T3 is unstable and reacts with 1D2 1D2 + 1T3 --> 2He4 + n Mev Total energy released is 5 1D2 --> 2He4 + 2He3 + H + 2n Mev

24 Atomic Fusion How Much Resource is Available?There is 1 1D2 atom per 6,500 H atoms in sea water One cubic meter of sea water contains 34.4 grams 1D2 Potential energy equals 269 metric tons of coal or 1,360 barrels of oil One cubic km of sea water equals 269 billion tons of coal or 1,360 billion bbls oil Exceeds the entire world oil resource