Fossil Fuels: Energy: IPCC 2022 PDF

Low-carbon energy sources ATMO 310/ OCN 310 Shutterstock November 20, 2024 Samuel Kekuewa IPCC 2022 IPCC 2022  Nuclear power Historically one of the major global contributors of carbon-free electricity It produces re...

Low-carbon energy sources ATMO 310/ OCN 310 Shutterstock November 20, 2024 Samuel Kekuewa IPCC 2022 IPCC 2022  Nuclear power Historically one of the major global contributors of carbon-free electricity It produces reliable, steady power the same way fossil fuel plants do Primarily used to generate electricity It faces public opposition and safety concerns in many places (accidents and nuclear weapons connection) It accounts for about 10% of electricity generation globally, and ~20% in the US Can nuclear power help decarbonize the power sector?  CO2 Production IPCC 2022  Nuclear fission Uranium (235U) is the fuel most widely used by nuclear plants for nuclear fission Graphic: A. Vargas/IAEA Nuclear reactions produce millions of times more energy than chemical reactions  Mining impacts Similar environmental impacts as mining coal, with the added hazard of radioactive mine tailings BUT While a 1GWe power plant needs 360 A nuclear plant needs 30 tons of tons of coal per hour uranium per year Credit: King County Wikipedia Source: Energy, Environment & Climate, Richard Wolfson  Long-lived radioactive waste Most waste has a relatively low level of radioactivity However, the spent reactor fuel waste is high-level nuclear waste: remains highly radioactive for tens of thousands of years The US does not currently have a permanent disposal facility for high-level nuclear waste  Environmental impacts Impacts of 1-GWe coal and nuclear power plants Impact Coal Nuclear Fuel 360 tons coal/hr 30 tons uranium/yr Air pollutants 400,000 tons/yr 6,000 tons/yr Carbon dioxide 1,000 tons/hr 0 Solid waste 30 tons ash/hr 25 tons HLW/yr Land use 17,000 acres 1,900 acres Radiation ~1 MBq/min 50 MBq/min varies with coal Source: Energy, Environment & Climate, Richard Wolfson Is nuclear power safe? Kharecha et al., 2013 Chernobyl Fukushima  Nuclear fusion Image: NASA/SDO/AIA Image: IAEA/M. Barbarino The energy that powers the sun and stars originates from nuclear fusion Still not able to make fusion in a controlled way to make electric power Four times more energy than nuclear fission reactions Fuel is plentiful: deuterium can be extracted from seawater and tritium can be produced from lithium. Does not produce any high activity long lived nuclear waste  Renewable energy Illustration by Egan Jimenez  Renewable energy Derived from natural sources that are replenished at a higher rate than they are consumed 1. Bioenergy 2. Hydropower 3. Geothermal 4. Solar energy 5. Wind 6. Marine energy Renewable energy (biomass) was the main energy source for most of human history Non-renewable energy began replacing most of renewable energy in the US in the 1800s  Solar energy Solar energy is the most abundant of all energy resources The rate of solar energy received by the Earth is about 10,000 times greater than human energy consumption Solar technologies convert sunlight into electrical energy or heat either through photovoltaic panels or through mirrors that concentrate solar radiation In the last 20 years, new technological advances have increased solar panel efficiency and lifetime, and significantly reduced costs  Solar energy Solar energy systems do not produce air pollutants or greenhouse gases (NOT FULLY TRUE – SF6) On buildings solar systems have minimal environmental impacts Solar panels have a lifespan of roughly 30 years The main limitation is the intermittency and variability The amount of sunlight varies depending on location, time of day, season of the year, and weather conditions. Large surface area required  Wind energy Wind energy harnesses the kinetic energy of moving air and converts it to electricity by using large wind turbines Wind turbines can be located on land (onshore) or at sea (offshore) Many parts of the world have strong wind speeds, but the best locations for generating wind power are sometimes remote ones Wind is not always a steady source of energy. Wind speed varies depending on the time of day, weather, and geographic location Wind turbines can be dangerous for bats and birds In modern wind turbines, wind rotates the rotor blades, which turn a generator converting kinetic energy into electrical energy Onshore and offshore wind energy technology has improved over the last few years maximizing the electricity produced - with taller turbines and larger rotor diameters. IPCC Special Report on Renewable Energy Sources and Climate Change Mitigation  Bioenergy Renewable energy from plants and animals Largest source of energy in the US until mid-1800s The use of biomass fuels for transportation and electricity generation is currently increasing in developed countries Biomass provides ~5% of total US primary energy consumption (primarily through biofuels and wood) Burning biomass releases greenhouse gases (although at lower levels than fossil fuels) Growing crops for biofuels requires large amount of land and pesticides If biomass feedstocks are not replenished fast enough biomass energy becomes non-renewable  Hydropower One of the first sources of energy used for electricity generation Hydroelectric power is derived from the energy of water moving from higher to lower elevations The amount of available energy in moving water depends on the water flow and the change in elevation It accounts for ~6% of total electricity and ~31.5% of total renewable electricity in the US  The world’s largest hydropower plant: Three Gorges Dam in China It produces 80 to 100 terawatt-hours per year, enough to supply between 70 million and 80 million households Conventional hydroelectric plants Hydroelectric power plants use the flow of rivers and streams to turn a turbine to power a generator, releasing electricity Most hydroelectric power plants are located on large dams, which control the flow of a river Dams block the river creating an artificial reservoir A controlled amount of water is released through hydro turbines as needed to generate electricity Fairly inexpensive, easy to build, fairly reliable Changes in the water cycle can have large effects on the availability of hydropower production Hydropower plants alter ecosystems Pumped hydroelectric storage Water is pumped to a storage reservoir at a higher elevation and is released as needed from the upper reservoir to power hydro turbines located below the upper reservoir Not energy sources but energy stores Typically use more electricity to pump water up than they produce with the store water→ negative electricity generation balances  Geothermal energy Geothermal energy is heat within the Earth, produced by the radioactive decay of particles in the Earth’s core The center of the Earth is extremely hot: 6,000°C or 10,800 °F People have used geothermal energy for thousands of years Geothermal energy is used for: Bathing Heating buildings Generate electricity The US produces the most geothermal energy In Iceland, geothermal energy accounts for 66% of primary energy use  Geothermal power and heat pumps Transitioning to clean energy technologies implies a significant increase in demand for minerals The energy sector becomes a leading consumer of minerals as energy transitions accelerate The increasing demand of these minerals is driven predominantly by electric vehicles and battery storage  Mining the deep ocean The increasing demand for minerals has resulted in growing interest in deep-sea mineral exploitation Many metals occur at economically interesting concentrations in the deep ocean (e.g. copper, cobalt, nickel, zinc, silver, gold) The metals are found in different settings: o Polymetalic nodules on abyssal plains (3,000-6,500 m depths) o Cobal-rich ferromanganese crusts on seamounts (800-2,500 m) o Polymetallic sulfides at hydrothermal vents Levin et al. (2020). Nature sustainability  Mining the deep ocean Polymetallic nodules, massive sulfides, and cobalt-rich crusts all provide critical habitat for deep- sea biota. Levin et al. (2020). Nature sustainability  Clarion-Clipperton Zone 4.5 million km2 Shaded boxes are areas > area of the European Union protected from mining Nearly width of the continental US  Highly diverse habitats that remain largely undiscovered or unidentified Photos: Craig Smith and Diva Amon/University of Hawai‘i at Mānoa  Visualizing deep-sea mining (MIT) https://www.youtube.com/watch?v=Lwq1j3nOODA Pelagic ecosystems can also be impacted by deep-sea mining Midwater animal biodiversity Squid, fish, shrimp, copepods, medusa, filter-feeding jellies, and marine worms among the midwater creatures that could be affected by deep-sea mining Drazen et al. (2020). PNAS  Summary There are a number of low-emission energy sources available to replace fossil fuel use Nuclear power is a non-renewable low-carbon source of energy that produces reliable, steady power the same way fossil fuel plants do Renewable energy derives from natural sources that are replenished at a higher rate than they are consumed. Examples are: bioenergy, hydropower, geothermal, solar, and wind Rapid cost reductions in wind, solar, and battery technologies make them highly competitive (or even cheaper) than continuing to use fossil fuels The shift to clean energy technologies is expected to dramatically increase the demand for minerals Companies are preparing to exploit ocean mineral resources for metals to fuel green technologies, which could have far reaching environmental consequences Fossil fuels ATMO 310/ OCN 310 November 18, 2024 What are fossil fuels? Fossil fuels are natural non-renewable resources Formed over hundreds of millions of years from organic matter (decomposing plants and animals) trapped under rocks and sediments below the Earth’s surface, and subjected to pressure and heat Fossil fuels are energy-dense, they can be burned to produce electricity or refined to use as fuel for heating or transportation Fossil fuels are the primary source for world’s energy  Types of fossil fuels Coal Petroleum (oil) Natural gas What is the difference in formation between coal and oil/gas? a) Coal is formed from land plants and oil/gas are formed from marine life. b) Oil/gas are formed from land plants and coal is formed from marine life. c) Coal was formed a million years ago whereas it takes only a few years for oil and gas to form. d) Both a and c.  Sources of energy Before Industrial Revolution: The availability of energy has Muscular (manual labor, animals) transformed the course of humanity over the last few centuries, being a Biomass (wood, crop waste, manure) driver of technological and economic development Source: The Geography of Transport Systems  Fossil fuel consumption has grown quickly since 1950 The types of fuel we use has shifted, from only coal to a combination with oil, and then gas Coal consumption is currently falling in many parts of the world Units 1 terawatt-hour (TWh) = 1012 watt-hours In 2020, U.S. coal production fell to its lowest level since 1965 What about renewable energy? During the 20th century hydropower, then nuclear (1960s) and then modern renewables (solar and wind, by the 1980s) were added to the mix Energy transitions in the past were slow Today we need a FAST transition  Coal Coal is a sedimentary rock PHOTOGRAPH BY JAMES P. BLAIR Formed from fossilized plants Energy dense Of all the fossil fuels, coal is the least expensive for its energy content Large reserves of coal globally (>1/4 of total known world coal reserves are in the US) Burning coal releases toxic gases and pollutants into the atmosphere Coal formation began in the Carboniferous period (359 to 299 million years ago) Carboniferous forest. Mark Ryan  Types of coal Types of coal: the quality of coal depends on the amount of carbon. Higher quality coal produces less smoke, burns longer, and provides more energy Moisture Dry, Carbon Dry, volatile Heat Content Coal content before content (%) content (%) (MJ/kg) drying (%) Anthracite 86-92 7-10 3-14 32-33 Bituminous coal 76-86 8-18 14-46 23-33 Sub-Bituminous 70-76 18-38 42-53 18-23 coal Lignite 65-70 35-55 53-63 17-18 Peat