ALTERNATE ENERGY SOURCES

Solar Energy Definition Of Solar Energy This is energy received from the sun by the Earth in the last 100 years Hydroelectric power Wind power PG & E 83 MW by 1990 SCE 43 MW by 1990 Wood Ocean currents Passive and direct solar power

Solar Energy Advantages of Solar Power Solar 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

Solar Energy Passive Solar Power Space heating Water heating

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

Water Power History and Potential Large 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

Water Power The Problems of Hydroelectric Power Dams 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

Tidal Power Same Basic Principle as Hydroelectric Power Tidal 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

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%. http://www.poemsinc.org/FAQtidal.html

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

List of World Main Tidal Power Stations Country 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 http://www.newenergy.org.cn/english/ocean/casestudy/tide/

Tidal Power La Rance, France - world's first tidal power plant Average tidal range 27 feet Dam encloses 8.5 sq. miles Capacity is 320,000 KW http://armorance.free.fr/barrage.htm

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

Geothermal Power Source of the Energy Conduction to the surface Convection by volcanoes and hot springs

Geothermal Power Two Methods of Recovery Dry Steam Geothermal Fields Steam 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

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

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

Atomic Fusion Possibility was first recognized by Hans Bethe 1939 - 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

Atomic Fusion Definitions Proton – a positively charged subatomic particle Neutron – a negatively charged subatomic particle http://www.kidzworld.com/site/p2066.htm

Atomic Fusion Definitions Isotope – 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 http://www.kidzworld.com/site/p2066.htm

Atomic Fusion Definitions Fission – 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

Atomic Fusion The 3 Isotopes of Hydrogen Hydrogen 1H1 Deuterium 1D2 Tritium 1T3

Atomic Fusion The Reactions 1D2 + 1D2 --> 2He3 + n + 3.2 Mev 106 electron volts) This produces a stable end product 1D2 + 1D2 --> 1T3 + H + 4.0 Mev 1T3 is unstable and reacts with 1D2 1D2 + 1T3 --> 2He4 + n + 17.6 Mev Total energy released is 5 1D2 --> 2He4 + 2He3 + H + 2n + 24.8 Mev

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