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Explore the fascinating aspects of the sun, including its mass, magnetic polarity, and the increase in its luminosity. Learn about nuclear fusion, solar flares, and the potential future effects of the sun on Earth. Discover the efficiency of solar photovoltaic panels and explore second-generation solar power options.
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Sun’s magnetic polarity flips regularly with 22-year cycle. Magnetic field is concentrated by 1000x in center of sunspots. Sun’s luminosity has increased by 30% since its birth --- now grows by 1% every 100 Myr. May cause a runaway Greenhouse on Earth in 500 Myr that will extinguish multicellular life.
Nuclear PhysicsBinding Curve Fission Fusion In its core, the Sun fuses 620 million metric tons of hydrogen each second.
Process of nuclear fusion within stars (fusing hydrogen into helium)
A full-disk multiwavelength extreme ultraviolet image of the sun taken by Solar Dynamics Observatory on March 30, 2010. False colors trace different gas temperatures. Reds are relatively cool (about 60,000 K); blues and greens are hotter (greater than 1 million K).
U.S. Energy Flow, 2006 (Quads) >70% of primary energy for the transportation sectorand >60% of primary energy for electricity generation/use is lost ~44% Efficiency 10 Source: LLNL 2008; data are based on DOE/EIA-0384(2006). Credit should be given to LLNL and DOE.
Total Rate of World Energy Use = 18 Terawatts 85% is from Fossil Fuels Total Power from the Sun at Earth’s Surface = 125,000 Terawatts!! ~7000x Total Human Energy Use 1 Hour of Sunlight = 1 Year of Human Energy Use
Solar Photovoltaic Commercial Panels: 12% Efficiency Experimental Panels: 22% Efficiency Nanotech Cells: >40% Efficiency Direct electric conversion with several materials Inexpensive organic materials now exceed 6% efficiency
For Large-Scale Production, Mirrors Easier/Cheaper Than Panels Example: Kramer Junction solar power plants, Mojave Desert, CA * 150 MW
Average Solar Power Potential (factoring in atmosphere, clouds & nighttime): ≈235 W/m2 With 10% efficiency: 150 Mw = Solar Farm 2.5 km x 2.5 km (“Cost” ≈ $0.25/kW/hr)
Increase in Solar Photovoltaic Power: But issues with toxicity and reliability