Solar Power and Biomass Energy

Passive vs. Active Solar Power

• Passive solar power uses building design and materials to capture and store solar energy without mechanical systems.
• Active solar power uses mechanical and electrical equipment to convert sunlight into usable energy.

How Solar Power is Used

• Active solar power is used to generate electricity or heat water.
• Passive solar power is used to heat and cool buildings through design elements.

Advantages of Solar Energy Conversion

• Solar thermal electric generation can produce electricity even without direct sunlight using thermal storage.
• Photovoltaic solar cells are a clean, renewable energy source that can be scaled for different applications.

Biomass Defined

• Biomass is organic material from plants and animals used as an energy source.

Biomass and Solar Energy

• Biomass is considered an indirect form of solar energy because plants use sunlight for photosynthesis, storing energy in the biomass.

Biomass Pros and Cons

• Advantages: Renewable, reduces waste, can be carbon-neutral, used for heating and electricity.
• Disadvantages: Can cause deforestation, releases greenhouse gases, requires large land areas.

Optimum Locations for Wind and Hydropower

• Wind energy is best in areas with high average wind speeds, like coastal regions and the Great Plains.
• Hydropower is best in areas with large water bodies or steep rivers, such as the Pacific Northwest.

Potential of Wind vs. Hydropower

• Wind energy has vast potential but is intermittent.
• Hydropower is more consistent but limited by water resources and can have environmental impacts.

Energy Sources from Solar Energy

• Wind energy is a result of the sun's uneven heating of the Earth's surface.
• Biomass results from photosynthesis, which uses solar energy.

Energy Conservation vs. Energy Efficiency

• Energy conservation is reducing energy consumption by using less energy.
• Energy efficiency is using technology or methods that require less energy to perform the same task.

Cogeneration Defined

• Cogeneration is the simultaneous production of electricity and useful heat from the same energy source.

Cogeneration Example

• A power plant uses natural gas to generate electricity and captures waste heat for district heating.

Biomass and Carbon Dioxide Levels

• Biomass can be carbon-neutral if managed sustainably, but unsustainable practices can lead to a net increase in CO₂ emissions.

Great Plains and Wind Power

• The Great Plains states are called the "Saudi Arabia of wind power" due to their strong, consistent winds and suitable land for wind farms.

Energy from Rivers vs. Oceans

• It is easier to obtain energy from a small, steep river because the water flow is more concentrated and predictable.

Geothermal pros and cons

• Pros: Reliable, renewable, minimal greenhouse gases, provides base-load power.
• Cons: Location-specific, high initial costs, may cause land subsidence or release harmful gases.

Renewable vs. Nonrenewable

• Nonrenewable energy resources exist in a fixed amount and cannot be easily replaced.
• Renewable energy sources are replenished naturally at or near the rate of consumption and can be reused.

Global energy use

• Energy resource use is unevenly distributed between developed and developing countries.
• Fossil fuels are the most widely used sources of energy globally.
• Developing countries rely more on fossil fuels as they become more developed.
• Increased industrialization leads to increased energy demand.
• Availability, price, and regulations influence energy source use.

Fuel Types

• Wood is commonly used as fuel, especially in less developed countries due to accessibility.
• Peat is partially decomposed organic material burned for fuel.
• Lignite, bituminous, and anthracite are three types of coal used for fuel.
• Heat, pressure, and burial depth contribute to coal type development and qualities.
• Natural gas, mainly methane, is the cleanest fossil fuel.
• Crude oil can be recovered from tar sands, a combination of clay, sand, water, and bitumen.
• Fossil fuels can be made into specific fuel types for specialized uses.

Cogeneration

• Cogeneration occurs when a fuel source generates both useful heat and electricity.

Renewable Resource Distribution

• The global distribution of natural energy resources (ores, coal, crude oil, gas) is not uniform and depends on geological history.

Burning Fossil Fuels

• Fossil fuel combustion is a chemical reaction between fuel and oxygen that yields carbon dioxide and water, releasing energy.
• Burning fossil fuels generates heat, turns water into steam, which turns a turbine to generate electricity.

Extracting Fossil Fuels

• Coal extraction involves surface and subsurface mining techniques.
• Oil and natural gas extraction involves drilling and fracking.
• Fracking can cause groundwater contamination and release VOCs.

Nuclear power

• Nuclear power is generated through fission, where Uranium-235 atoms are split by neutrons.
• Nuclear fission releases heat, which generates steam to power a turbine, generating electricity.
• Radioactivity occurs when a radioactive isotope's nucleus loses energy by emitting radiation.
• Uranium-235 remains radioactive for a long time, causing nuclear waste disposal problems.
• Nuclear power generation is a nonrenewable energy source.
• Nuclear power is a cleaner energy source because it does not produce air pollutants, but produces thermal pollution and hazardous solid waste.

Nuclear Accidents

• Three Mile Island, Chernobyl, and Fukushima are cases where accidents or natural disasters released radiation.
• Radiation releases have short and long-term environmental impacts.
• An element’s half-life calculates decay and radioactivity levels over time.

Biomass fuel

• Biomass burning produces heat at a relatively low cost, but also produces carbon dioxide, carbon monoxide, nitrogen oxides, particulates, and VOCs.
• Overharvesting trees for fuel causes deforestation.

Ethanol

• Ethanol as a gasoline substitute.
• Burning ethanol does not introduce additional carbon into the atmosphere via combustion.
• The energy return on energy investment is low for ethanol.

Solar energy

• Photovoltaic solar cells capture light energy and transform it into electrical energy.
• Photovoltaic use is limited by sunlight availability.

Active Solar Energy

• Active solar energy systems heat liquid through mechanical and electric equipment to collect and store solar energy.

Passive Solar Energy

• Passive solar energy systems absorb heat directly from the sun without mechanical and electrical equipment.
• Energy in passive solar energy systems cannot be collected or stored.

Solar Power Environmental Impact

• Solar energy systems have low environmental impact and produce clean energy, but can be expensive.
• Large solar electric energy farms may negatively impact desert ecosystems.

Hydroelectric Power

• Methods: Dam built across a river, water moves through the dam and turns a turbine, or turbines placed directly in the flow of smaller rivers.
• Hydropower does not generate air pollution or waste.
• Construction of plants and dams can be expensive.
• Dams alter river ecosystems, affect species migration, and change sediment flow.
• Tidal power uses energy produced by tidal flow to turn a turbine.

Geothermal Energy

• Geothermal energy uses heat stored in the Earth's interior to heat water, which is brought to the surface as steam
• Steam is used to drive a turbine to spin an electric generator
• Geothermal can be prohibitively expensive
• Geothermal is not accessible in many areas of the world
• Geothermal can cause the release of toxic hydrogen sulfide

Hydrogen Fuel Cell

• Use hydrogen as fuel
• Combines hydrogen with oxygen to form water and release energy (electricity).
• Water is the byproduct (emission) of a fuel cell. Hydrogen fuel cells have low environmental impact.
• Hydrogen fuel cells produce no CO2 when the Hydrogen is produced from water.
• Hydrogen fuel cell technology is expensive.
• Energy is still needed to create the hydrogen gas used in the fuel cell.

Wind Energy

• Wind turbines use kinetic energy of moving air to spin a turbine
• Mechanical energy of the turbine is converted into electricity
• Wind energy is clean and renewable, but birds and bats may be killed flying into turbines
• Wind energy may spoil an areas aesthetics and needs for transmission lines.

Energy Conservation

• Home conservation methods include adjusting the thermostat, conserving water, using energy-efficient appliances, and conservation landscaping.
• Large scale conservation methods include improving fuel economy of vehicles, using BEVs and hybrid vehicles, using public transportation, and implementing green building designs.

Organisms Transform Energy

• All organisms transform energy
• Energy = the capacity to do work kinetic (motion) and Potential energy types
• Chemical energy is important In living organisms
• Conversions of chemical energy are the basis of life

Energy Laws

• 1st Law: Energy can be transferred and transformed but it can never be created nor destroyed
• 2nd Law: Every energy transfer or transformation increases the entropy of the universe

Energy Types

• Radiant – Light (photons) Nuclear – contained in nuclear attraction between protons and neutrons
• Chemical – Stored in the bonds between atoms in molecules Mechanical – motion of objects
• Thermal – heat energy in the movement of molecules electrical – movement of electrons

Examples of Energy

• High Quality Energy Electricity, Chemical E stored in coal and gas, Concentrated sunlight, Nuclei of U-235, Concentrated Heat.
• Low Quality Energy Heat in dispersed in the atmosphere, Heat stored in an ocean.

Energy on Earth

• The source of all energy on Earth is the sun. And radiant energy supports photosynthesis.
• The sun also powers the cycling of matter, drives climate and weather.
• The sun consists of 72% hydrogen, 28% helium.

Energy to the earth

• Earth receives 1 billionth of the suns energy. and also Earth has an albedo effect.
• Of that energy 34% of solar energy reflected back into space by atmosphere (albedo effect).

Energy used

• 0.023% captured by producers for photosynthesis
• Energy eventually transformed to heat and trapped by atmosphere “Natural Greenhouse Effect”.

Fossil Fuels

• Fossil fuels are combustible deposits in the Earth’s crust and are non-renewable resouces.

Coal Grades

• Coal also occurs in different grades based on variations in heat and pressure during burial ex: Lignite, Subbitumimous, Bituminous, Anthracite.
• US has 25% of world’s coal supplies.

2 Types of Coal Mining

• Surface mining if coal is within 30m of surface & Subsurface mining.
• https://www.youtube.com/watch?v=aiSzOiGFa-0 & Mountaintop removal coal mining.

Environmental Impacts of Mining Coal

• Surface Mining Control and Reclamation Act (1977),Requires filling (reclaiming) of surface mines after mining. & expensive. Also Mountaintop Removal fills valleys and streams with debris.
• Most land destructive technique.

Environmental Impacts of Burning Coal

• Releases large quantities ofCO2 into atmosphere which is a Greenhouse gas.
• Releases other pollutants into atmosphere include Mercury, Sulfur oxides and Nitrogen oxides, also can cause acid precipitation.
• Making Coal Cleaner by Scrubbers or Fluidized Bed Combustion.

Oil and Natural Gas

• Oil and gas provide 60% of world’s energy
• Petroleum Refining Numerous hydrocarbons present in crude oil (petroleum) separated Based on boiling point.
• Oil and Natural Gas ExplorationOil and natural gas migrate upwards until they hit impermeable rock Usually located in structural traps
• Oil Reserves / Use Uneven distribution globally More than half is located in the Middle East.

Tar Sands

• https://www.youtube.com/watch?v=Sjia7BsP4Bw: Bitumen or oil sands.

How long will supplies last

• Experts indicate there may be shortages in 21st century Long lines at gas station as a result of theOPEC oil embargo in 1973 -Environmental Impacts of Burning Oil and Natural Gas Combustion Increase carbon dioxide and pollutant emissions (nitrogen oxides/photochemical smog).

Environment

• https://www.youtube.com/watch?v=Sjia7BsP4Bw: Natural gas is far cleaner burning than oilProduction, Disturbance to land and habitat.
• Transport Spills- especially in aquatic systems ex: Alaskan Oil Spill (1989),https://www.youtube.com/watch?v=aiSzOiGFa-0.

Natural Gas:

• See Gasland notes Natural Gas Reserves Uneven distribution globally,https://www.youtube.com/watch?v=aiSzOiGFa-0
• More than half is located in Russia and Iran

Synfuel

• Synfuel, A liquid or gaseous fuel that is synthesized from coal and other naturally occurring sources Used in place of oil or natural gas. Include: Tar sands, Oil shales, Gas hydrates:https://www.youtube.com/watch?v=aiSzOiGFa-0 Liquefied coal
• Coal gas US Energy Strategy Objective.

Nuclear Process

• Fission – nuclear energy released when atom split Fusion – nuclear energy released when atoms fused.
• Nuclear reactions have the potential to release a vast amount of energy, primarily as heat. Energy is equal to Mass times the speed of light squared.
• Atoms Atomic mass = the sum of the protons and the neutrons in an atom.

Radioactive isotopes

• Unstable isotopes are called radioisotopes and are said to be radioactive.
• Conventional Nuclear FissionUranium ore is a nonrenewable resource present in limited amounts and found in sedimentary rocks.

Nuclear Fission

• Starting at the left side Neutron bombardment of uranium-235 causes the nucleus to split into smaller atomic fragments and several free neutrons.
• Those free neutrons then bombard others and cause a chain reaction, producing nuclear energy
• https://www.youtube.com/watch?v=aiSzOiGFa-0.Nuclear Fuel Cycle Uranium mines U-235 Fabricatio.

How electricity is made by nuclear energy

• How electricity is produced from nuclear energy A typical nuclear power plant has four main parts: the reactor core, steam generator, turbine and condenser.
• Fission occurs in the reactor core and the heat that is produced is used to produce steam from liquid water in the steam generator.
• Breeder Nuclear Fission U-238 is converted to plutonium Pu-239 which is human-made andfissionable

Pros and cons of Nuclear Energy

• Power Plants Can Nuclear Energy Decrease Our Reliance on Foreign Oil?
• Only 3% of electricity in US generated by oil
• Oil primarily used for -heating buildings -vehicles Safety Issues in Nuclear Power Plants Probability of major accident low, but if it occurs, consequences are wide-spread and long-lasting Major accidents have included: Three Mile Island Chernobyl Fukashima.
• Safety Issues in Nuclear Power Plants Radioactive fallout from Chernobyl. Spent fuel from conventional nuclear plant Fuel for breeder reactor.
• Two types of radiaoctive nuclear waste of High and low level.

Direct Solar Energy

• Varies with latitude, season, time of day, and cloud cover Heating Buildings and Water Passive solar energy
• Passive Solar System of putting the sun’s energy to use without requiring mechanical devices to distribute the collected heat Certain design features can enhance passive solar energy’s heating potential example South facing windows, Well insulated buildings.

Solar Thermal

• Solar Thermal Electric Generation Means of producing electricity in which the sun’s energy is concentrated by mirrors or lenses to either heat a fluid filled pipe or drive a Stirling engine- Solar Thermal Electrical Benefits No air pollution No contribution to global warming or acid precipitation.
• CSP Photovoltaic Solar Cells Thin cells are treated with certain metals and silicon so that they generate electricity when they absorb solar energy.
• PV Convert sunlight directly into energy. No pollution and minimal maintenance

Solar tiles

• Can be incorporated into building materials – Roofing shingles – Tile – Window glass. Cost of Electrical Power Plants.

Indirect Solar

• Biomass Plant materials used as fuel Example: wood, crop wastes, sawdust, and animal wastes Contains energy from sun via photosynthesizing plants.Can convert to biogas or liquids Ethanol and methanol. Advantages Reduces dependence on fossil fuels Often uses waste materials
• IfTrees are planted at same rate biomass is combusted, no net increase in atmospheric CO2. Disadvantages Requires land, water and energy Can lead to Deforestation Desertification, Soil erosion

Windy Power

• Indirect Solar Wind Energy Electric or mechanical energy obtained from surface air currents caused by solar warming of air World’s fastest growing source of energy Wind results from sun warming the atmosphere Varies in direction and magnitude

Wind Energy Negatives

• Kills birds and bats, Cost constrants. Positives, no waste, clean & Most profitable in rural areas with constant wind.
• Few environmental problems. Hydropower Form of renewable energy reliant on flowing Also Falling water to generate mechanical energy or electricity that is most efficient.

Damped Energy

-Generates 19% of world’s energy Traditional hydropower and suited for large dams New technologyMay be able to utilize low flow waterwaysProblems with Dams Changes Natural flow of rivers Disrupts migratory fish patterns Potential dam breaks.

Ocean Energy

Other Indirect Solar Energy Ocean waves Produced by winds Has potential to turn a turbine and create electricity Ocean Temperature Gradients Use difference in temperature of surface and deep water to create electricity Other Renewable Energy Sources.

High and Low technology Energy Solution

Global Energy Consumption:

Coal: 27% Oil & Gas: 53% Renewable Energy: 13% Nuclear Energy: 7%

United States Energy Consumption:

Coal: 13% Oil & Gas: 69% Renewable Energy: 8% Nuclear Energy: 10%

Energy Efficiencies and Levelized Costs of Electricity (LCOE). The efficiency and cost of electricity generation vary by energy source:

Solar Photovoltaic (Utility-scale): $24–$96 per MWh Wind (Onshore): $24–$75 per MWh Wind (Offshore): $72–$140 per MWh Nuclear: $69 per MWh Coal (Ultra-supercritical): $88 per MWh Natural Gas (Combined Cycle): $71 per MWh