Algonquin College SCI4001 Biodiversity Lecture 12_F24 PDF

WEEK 12 ALTERNTIVE ENERGY COURSE SCI4001_24F BIODIVERSITY AND CONSERVATION Last week: Air quality Atmosphere and weather Outdoor pollution Sources of air pollution Washington Post, March 30, 2005 This week…… Reasons for seeking altern...

WEEK 12 ALTERNTIVE ENERGY COURSE SCI4001_24F BIODIVERSITY AND CONSERVATION Last week: Air quality Atmosphere and weather Outdoor pollution Sources of air pollution Washington Post, March 30, 2005 This week…… Reasons for seeking alternatives to fossil fuels Contributions to world energy supplies of conventional alternatives to fossil fuels Environmental impacts of hydroelectric power, nuclear power, and biomass energy “New renewable” alternative sources of energy and assess their potential for growth Biomass, solar, wind, geothermal, and ocean energy technologies, and outline their advantages and disadvantages Hydrogen and fuel cells and assess future options for energy storage and transportation Washington Post, March 30, 2005 World Energy Consumption 17-4 World Energy Consumption by source Globally we get ~80% of our energy from oil, followed by coal, and natural gas Fuelwood and other biomass sources provide 10% of the world’s energy, nuclear power provides 5%, and hydropower provides 2% https://www.eesi.org/topics/fossil- fuels/description#:~:text=Fossil%20fuels%E2%80%94including%20coal%2C%20oil, percent%20of%20the%20world's%20energy.  Energy production – mainly the burning of fossil fuels – accounts for 80% of global greenhous e gas emissions.  Hydropower, nuclear power, and biomass energy are conventional alternatives Hydro power has been Canada's primary energy source (62% in 2022) Growth in new renewable energy sources such as wind, solar, and tidal waves (expected to reach 12% of the total power generation by 2035) Shift in Canada's energy landscape, with a notable increase in the adoption of sustainable power generation methods 17-7 Alternatives to Fossil Fuels 17-8  Alternative Energy Alternative energy is energy that does not come from fossil fuels, and thus produces little to no greenhouse gases like carbon dioxide (CO2). Energy produced from alternative sources does not contribute to the greenhouse effect that causes climate change. 17-9 Sources of alternative energy Bioenergy Hydro power Nuclear Solar Wind power Geothermal Ocean energy Hydrogen fuel and power storage https://earthhow.com/alternative-energy-sources/#google_vignette Bioenergy 17-11  Biomass energy Biomass = organic material that makes up living flora Contains chemical energy that originated with sunlight and photosynthesis Biopower = produced when biomass sources are burned in power plants, generating heat and electricity Biofuels = biomass sources converted into fuels to power vehicles 17-12 Traditional biomass sources are widely used in the developing world Over 1 billion people still use wood from trees as their principal energy source Fuelwood, charcoal, and manure account for 35% of energy use - In the poorest nations it may be up to 90% Fuelwood and other biomass sources constitute 75% of all renewable* energy used worldwide. Well over a billion people in developing countries rely on wood from trees for heating and cooking 17-13 Traditional biomass energy has environmental pros and cons It is essentially carbon-neutral, releasing no net carbon into the atmosphere. Only if: Biomass sources are not overharvested Forests are not destroyed to plant bioenergy crops We do not consume fossil fuel energy to produce the biomass 17-14  Biomass can be processed to make vehicle fuels Ethanol = produces as a biofuel by fermenting carbohydrate-rich crops (corn) Any vehicle will run well (with even more complete combustion) on gasoline blended with up to 10% ethanol. Flexible fuel vehicles = run on 85% ethanol Biodiesel = biofuel for diesel engines produced from vegetable oils (canola) 17-15 Electricity can be generated from biomass By enhancing energy efficiency and putting waste products to use, biopower helps move utilities and industries in a sustainable direction. 17-16 Biofuels have environmental and economic benefits Biopower helps alleviate climate change - Capturing landfill gas reduces emissions of methane - Replacing gasoline with biofuels reduces emissions of nitrogen oxides, greenhouse gases, and other pollutants Biopower also benefits human health - Adding biofuels helps fossil fuels combust more completely, reducing pollution - Reduces Sulphur dioxide emissions when used instead of coal Economic benefits such as supporting rural communities and help reducing dependence of fossil fuel imports 17-17 Biofuels are not our most sustainable energy choice EROI (energy returned on investment): Ratio indicating how much energy is produced for each unit of energy invested in the energy-producing activity. Life-cycle analysis: Energy invested in finding, extracting, transporting, and using a resource.  Biofuels are not our most sustainable energy choice, yet… Growing crops exerts tremendous impacts on ecosystems - Fertilizers and pesticides - Land is converted to agriculture Proponents of food security voice ethical concerns: Biofuel is competing with food production Novel biofuels are being developed: - Algae - Cellulosic ethanol 17-19 Hydroelectric Power 17-20 Modern hydropower uses two approaches Storage Technique Hydroelectric power = uses the kinetic energy of moving water to turn turbines and generate electricity Approaches: Storage technique = impoundments harness energy by storing water in Run-of-River reservoirs behind dams System Run-of-river approaches generates energy without greatly disrupting the flow of river water 17-21 Hydropower is clean and renewable, yet has impacts However, dams: Hydropower has 3 main advantages over fossil fuels for - Destroy habitats producing electricity: - Disrupt natural flooding cycles 1. It is renewable: as long as - Cause thermal pollution which precipitation fills rivers, we can can eliminate fish populations use water to turn turbines - Block passage of fish, fragmenting 2. It is clean: no carbon dioxide the river and reducing biodiversity is emitted * - Have geological impacts (e.g. 3. It is efficient: has an EROI of earthquakes) 80:1, higher than any other - Have other social and economic modern energy source. impacts on local communities 17-22 Nuclear Power 17-23  Fission releases nuclear energy Nuclear energy = the energy that holds together protons and neutrons within the nucleus of an atom Nuclear fission = the splitting apart of atomic nuclei We harness this energy by converting it to thermal energy inside nuclear reactors 17-24 Electricity-generating process  Fission takes place in nuclear power plants The neutrons bombarding uranium fuel in a reactor are slowed down with a substance called a moderator (most often water) Control rods = soak up excess neutrons produced and are placed into the reactor among the fuel rods Generates electricity without creating air pollution from stack emissions (avoiding 7% of global CO2 emissions every year). International Atomic Energy Agency – 150X less emissions than fossil fuel combustion Take into account not only emissions but mining, transport of fuel, manufacturing of equipment, construction of power plants, disposal of wastes and decommissioning of plants 17-26 Coal versus nuclear power 17-27 Radioactive waste disposal remains problematic The long half-life of uranium, plutonium, and other radioisotopes will cause them to continue emitting radiation for thousands of years a) Must be stored in unusually stable and secure locations and monitored for years Currently nuclear waste from power generation is held in temporary storage at nuclear power plants in Canada and other b) places around the world 17-28 Radioactive waste disposal remains problematic Spent fuel rods sunken in pools of water to minimize radiation leakage Some store wastes in thick casks of steel, lead, and concrete In Lac du Bonnet, Manitoba, scientists are testing proposals for long-term storage deep underground in the stable, ancient crystalline rocks of the Canadian Shield Geological isolation 17-29 Multiple dilemmas have slowed nuclear power’s growth It is enormously expensive to build, maintain, operate, and ensure the safety of nuclear facilities Electricity is more expensive than from coal and other sources Nuclear power plants in Western Europe will be retired by 2030 Asian nations are increasing nuclear capacity; 15 plants are under construction Chernobyl New Safe Confinement 17-30  Fusion remains a dream Nuclear fusion = forcing together the small nuclei of lightweight elements under extremely high temperature and pressure - drives our sun’s vast output of energy - Have not yet developed “cold” fusion for commercial power generation - If we could control fusion, we could produce vast amounts of energy from water 17-31 “New” Renewable Energy Sources 17-32  “New” renewable contributions are small but growing quickly In 2023, renewable energy sources accounted for approximately 30% of global electricity production. The main contributors to this mix were: Solar Power: The largest contributor, with significant capacity additions and growth. Wind Power: Another major contributor, with substantial increases in capacity. Hydropower: Continues to be a significant source, though its growth rate has slowed compared to solar and wind. Bioenergy: Contributes a smaller portion compared to solar and wind but remains part of the renewable mix. 17-33 The transition won’t happen overnight Solar Energy 17-35  Solar Power Clean and Renewable: A sustainable alternative to fossil fuels. Operation: Harnesses sun’s rays to generate electricity without GHG emissions during operation. Technology: Uses photovoltaic cells for electricity and solar thermal systems for heating. Cost and Efficiency: Advancements in technology have led to reduced costs and increased efficiency. Climate Impact: Significant role in reducing carbon footprint and decreasing reliance on non- renewable energy resources. Adoption worldwide is a key solution in the fight against climate change. Passive solar heating is simple and effective Passive solar energy = the most common way to harness solar energy Design: Buildings optimized for sunlight absorption in winter and cooling in summer. Window Placement: South-facing windows enhance winter heat; overhangs reduce summer sunlight. Thermal Mass Materials: Straw, brick, concrete - store and release heat. Strategic Location: Captures sunlight in winter, radiates interior heat, and absorbs heat in summer. Vegetation: Planted strategically for climate control. 17-37 Active solar energy collection can heat air and water in buildings Active solar energy collection = uses technology to focus, move, or store solar energy Flat plate solar collectors (solar panels) = active method for harnessing solar energy 17-38  PV cells generate electricity directly Photovoltaic (PV) cells = collect sunlight and convert it into electrical energy Photovoltaic (photoelectric) effect = occurs when light strikes one of a pair of metal plates in a PV cell, causing the release of electrons, creating an electric current A PV cell has two silicon plates, the n-type layer (rich in electrons) and the p-type layer (electron poor) Sunlight causes electrons to flow from the n- type to the p-type layer, generating electricity 17-39 Active solar energy collection can heat air and water in buildings (cont’d) Mirrors concentrate sunlight onto receivers to create electricity 17-40 Solar power offers many benefits Pros Cons Solar technologies are quiet, safe, use Site dependent no fuels, contain no moving parts, and Daily or seasonal variation in sunlight can require little maintenance pose a problem in stand-alone systems They allow local, decentralized control - Far northern locations over power Birds may be scorched to death as they fly Developing nations can use solar through cookers, instead of gathering firewood Desert environments are particularly Net metering = PV owners can sell sensitive excess electricity to their local power - Altered conditions hurt native desert- utility adapted species while helping invasive Clean weeds Up-front cost of equipment (the most expensive among all renewable energy sources) 17-41 Wind Energy 17-42 Wind Energy Wind energy = energy derived from moving air masses (an indirect form of solar energy) Wind turbines = devices that harness power from wind Windmills have been used for centuries to pump water to drain wetlands and irrigate crops and to grind grain into flour The largest wind power producer in Canada is the Le Nordais project in the Gaspé Peninsula 17-43 Wind is the fastest-growing energy sector Wind power is growing fast— doubling every three years In Denmark, wind supplies 40% of nation’s electricity In Canada, wind power could meet 15% of the nation’s electrical needs Today, wind power produces electricity for nearly the same price as conventional sources 17-44 Wind is the fastest-growing energy sector Wind speed are roughly 20% greater over water than over land and wind is less turbulent Winter weather also promotes stronger wind conditions  Wind power has benefits and downsides Pros Cons Wind produces no emissions once We have no control over when wind will installed occur It is more efficient than conventional power Companies have to invest a lot of sources research before building a costly wind Turbines also use less water than farm conventional power plants Good wind sources are not always near Farmers and ranchers can lease their land population centers that need energy Produces extra revenue NIMBY syndrome near population Landowners can still use their land for centers other uses Wind turbines also pose a threat to birds Advancing technology is also driving down and bats, which can be killed when they the cost of wind farm construction fly into rotating blades 17-46 Geothermal Energy 17-47 Geothermal energy Renewable energy is generated from deep within the Earth Harnessing the natural heat generated by the Earth's core and transferring it to the surface in the form of hot water or steam This heat rises through magma, fissures, and cracks Geothermal power plants use heated water and steam for direct heating and generating electricity Flash steam cycle 17-48 We can harness geothermal energy for heating and electricity 17-49 Use of geothermal power is growing Currently, geothermal energy provides less than 0.5% of the total energy used worldwide It provides more power than solar and wind combined But, much less than hydropower and biomass Commercially viable only in British Columbia In the right setting, geothermal power can be among the cheapest electricity to generate 17-50  Geothermal power has benefits and downsides Pros Cons Renewable resource that constantly Location dependent. Only viable in areas replenished by the natural heat of the earth. with accessible underground heat. Costly exploration (drilling) and infrastructure Stable and continuous supply of energy Potential environmental risks (e.g., Low spatial footprint compared to solar or earthquakes and groundwater contamination) wind While renewable, performance of wells can Low CO2 emissions relative to fossil fuels diminish if heat extraction exceeds natural replenishment rate Once a plant is established, the operational and maintenance costs are relatively low Requires a substantial amount of water for cooling and steam generation Scalable: small-scale domestic use or large- scale power generation 17-51 Ocean Energy 17-52 We can harness energy from tides, waves and currents Sources: Tides, waves, and ocean currents Technologies include tidal barrages, tidal lagoons, and underwater turbines Emerging Trends: Floating Tidal Energy Converters (FTECs) Dynamic Tidal Power (DTP) Global advancements in the UK, Canada, and South Korea 17-53 We can harness energy from tides, waves and currents (cont’d) The motion of wind-driven waves at the ocean’s surface is harnessed and converted from mechanical energy into electricity Wave energy can be developed at a greater variety of sites than tidal energy Offshore or coastal Wave energy is greatest at deep-ocean sites 17-54  Case Study: Harnessing Tidal Energy at the Bay of Fundy “Not only will atomic power be released, but someday we will harness the rise and fall of the tides and imprison the rays of the Sun.” THOMAS A. EDISON, 1921 Large tidal ranges makes the Bay of Fundy one of the most suitable locations in the world for generating power from ocean tides Site of three tidal power plants Tidal power does not entail negative impacts of traditional hydroelectric dams Major impacts involve interference with normal currents and with marine life Visit link on Brightspace! 17-55  Ocean energy advantages and challenges Pros Cons High initial costs and complex Clean and renewable engineering High predictability and reliability Environmental impacts on marine life and habitats Minimal greenhouse gas emissions Limited suitable locations for effective Potential to boost local economies power generation and create jobs 17-56 Conclusion Many people are convinced that we need to shift to renewable energy sources that will not run out and will pollute far less Renewable sources include solar, wind, geothermal, and ocean energy sources and hydrogen fuel Renewable energy sources have been held back by inadequate funding and by artificially cheap prices for nonrenewable resources Whether we can also limit environmental impact will depend on how soon and how quickly we make the transition 17-57 Next Week…… Environmental ethics…..