Download Renewable Energy vs. Nuclear Power: A Comparative Analysis - Prof. James L. Nagle and more Study notes Physics in PDF only on Docsity! 1 Reminders: • Research Project #1 due on Friday - Make sure to review paper requirements - See me if you have questions - Must be handed in (not emailed) • Next homework will be assigned on Wednesday, and due the next Wednesday. • Reminder of Extra Credit #5 – Forum this Thursday. Energy Balance? Carbon Neutral? Does farming produce more energy than it uses? – Fertilizers, water transport, farm machinery • Estimate in the text based on solar energy conversion is not the main issue Can we grow enough plant material to make a difference? – Switchgrass, other non-food crops – Change to more vegetarian diet Should we divert agricultural products from food to fuel? NIMBY ? = “Not In My Back Yard” People do not like incinerators. High costs for separation. Currently about 15% of waste is burned. Few Other Renewables Discussed in Chapter 5… • Ocean Thermal Energy Conversion (OTEC) • Geothermal Energy • Tidal Energy Some of these seem like obvious big energy sources, but there are very significant practical issues. These and others are very interesting, but not major players right now. Read some details in Chapter 5. Ocean Thermal Energy Conversion • Heat engine driven by thermal gradient between surface and deeper ocean layers – Very small Carnot efficiency • Turbine driven by ocean currents – Potentially serious environmental impacts • Very large capital costs 2 Geothermal Energy Potential Warm core of earth (radioactive in origin). Heat flow out from core < (1/1000) of flow in from sun. Most places the flow rate is too low to make use of, but “hot spots” (geysers, volcanoes) might be tapped. Places like Iceland have this working quite well (1/3 of their energy). World wide all operating and planned facilities 1% of current global electrical production. Hydrothermal systems Hot dry rock (igneous systems) Normal geothermal heat (200 C at 10 km depth) Many sources are not renewable (e.g. “Geysers” in California). Over time one uses up the local heat source! 1.3 GW capacity in 1985 Summary on Renewables Key message: there is no “easy fix”. Even maximizing and combining all of wind, solar, OTEC, biomass, geothermal, tidal, etc., we are still not able to match our current (and increasing) energy demands. We need to provide incentives to develop these alternatives and they can be expanded by factors of 10-100 ! However, a key part has to be reducing demand. Remember that our demand is doing the opposite (it is increasing). Watch out for numbers that quote the demand per person since the number of people is also increasing. Nuclear Energy Clicker Question What is the first thing you associate with the word “nuclear”? A) The solution to our energy problems B) The Atomic Bomb C) Magnetic Resonance Imaging (MRI) D) Three Mile Island E) Death F) Words that are difficult to pronounce Is that pronounced "nu-clear" or "nuke-ular"? MRI is really nuclear magnetic resonance imaging, but for some reason people were more apprehensive about a “nuclear test”.
