Podcast
Questions and Answers
What is the primary function of a solar module in a photovoltaic system?
What is the primary function of a solar module in a photovoltaic system?
Which component in a solar photovoltaic system prevents the battery from overcharging?
Which component in a solar photovoltaic system prevents the battery from overcharging?
What is a significant advantage of solar energy in relation to energy independence?
What is a significant advantage of solar energy in relation to energy independence?
What is the outcome of the PV Manufacturing Research and Development Project?
What is the outcome of the PV Manufacturing Research and Development Project?
Signup and view all the answers
Which type of energy does solar power primarily rely on?
Which type of energy does solar power primarily rely on?
Signup and view all the answers
Which of the following is a disadvantage of producing solar energy?
Which of the following is a disadvantage of producing solar energy?
Signup and view all the answers
What happens in solar photovoltaic systems when sunlight hits the solar cell?
What happens in solar photovoltaic systems when sunlight hits the solar cell?
Signup and view all the answers
Why is iron considered a 'dead end' in nuclear fusion and fission processes?
Why is iron considered a 'dead end' in nuclear fusion and fission processes?
Signup and view all the answers
What is the typical conversion efficiency of single crystalline silicon photovoltaic cells?
What is the typical conversion efficiency of single crystalline silicon photovoltaic cells?
Signup and view all the answers
Which component is primarily used to make single-crystal silicon cells?
Which component is primarily used to make single-crystal silicon cells?
Signup and view all the answers
What unique property of selenium is utilized in high-efficiency multi-junction solar cells?
What unique property of selenium is utilized in high-efficiency multi-junction solar cells?
Signup and view all the answers
Which of the following types of radiation is NOT a component of solar radiation?
Which of the following types of radiation is NOT a component of solar radiation?
Signup and view all the answers
The primary function of flat plate collectors in solar technology is to:
The primary function of flat plate collectors in solar technology is to:
Signup and view all the answers
What percentage of the total renewable energy consumed in the United States is currently attributed to solar energy?
What percentage of the total renewable energy consumed in the United States is currently attributed to solar energy?
Signup and view all the answers
Isolation, also known as incident solar radiation, refers to:
Isolation, also known as incident solar radiation, refers to:
Signup and view all the answers
What is the main purpose of doping the wafers in photovoltaic cells?
What is the main purpose of doping the wafers in photovoltaic cells?
Signup and view all the answers
Which of the following efficiencies is the highest among photovoltaic technologies mentioned?
Which of the following efficiencies is the highest among photovoltaic technologies mentioned?
Signup and view all the answers
How do solar cells produce electricity?
How do solar cells produce electricity?
Signup and view all the answers
What factors determine the size of a solar array?
What factors determine the size of a solar array?
Signup and view all the answers
What characterizes the photoelectric effect as it pertains to solar cells?
What characterizes the photoelectric effect as it pertains to solar cells?
Signup and view all the answers
What is a disadvantage of using amorphous silicon in photovoltaic materials?
What is a disadvantage of using amorphous silicon in photovoltaic materials?
Signup and view all the answers
What is required when solar photovoltaic systems are used for AC equipment?
What is required when solar photovoltaic systems are used for AC equipment?
Signup and view all the answers
Which type of layer in a solar cell is responsible for holding extra electrons?
Which type of layer in a solar cell is responsible for holding extra electrons?
Signup and view all the answers
What potential problem is associated with using Cadmium Telluride in photovoltaic materials?
What potential problem is associated with using Cadmium Telluride in photovoltaic materials?
Signup and view all the answers
Study Notes
International & Access Foundation Programmes
- Engineering Module - Semester 1
- Electronic & Electrical Engineering
- Part 1.1 Renewable Energy
- Delivered by Dr Nevan Bermingham
The Need for Renewable Energy
- Fossil fuel reserves and consumption data from CIA World Factbook
- Graph shows declining fossil fuel reserves (coal, gas, and oil) between 2011 and 2081
- Graph shows a rising trend in atmospheric carbon dioxide levels over time
- Current level significantly higher than the 1950 level.
Global Temperature and CO2
- Graph displays annual average temperature and atmospheric CO2 levels from 1880 to 2013
- Graph shows a rising trend in both temperature and CO2 levels.
Climate Change
- Objective truths are established by evidence. Personal truths are by faith. Political truths are by incessant repetition.
- Climate change is a reality.
- "Global Warming" is not an entirely accurate term but sea and air temperatures are rising and that energy manifests itself in erratic and extreme changes.
- The data is clear – the climate is changing and it will impact on our species; conspiracy theories & science denials do nothing to fix the issue.
- There is a very strong correlation with human activity but it's more difficult to prove causality.
- Technology is the key to solving this issue.
The Need for Renewable Energy (continued)
- Global sea level rose about 17 cm in the last century.
- The rate in the last decade is nearly double that of the last century.
- Earth has warmed since 1880.
- Most of this warming has occurred since the 1970s
- 20 warmest years occurred since 1981; all 10 of the warmest years occurred within the last 12 years
- Extent and thickness of Arctic sea ice has declined rapidly over the last several decades
- Increasing numbers of intense rainfall (storms) since 1950
Global Land-Ocean Temperature Index
- Data source: NASA's Goddard Institute for Space Studies.
- Temperature difference presented from 1884 to 2020.
- Data shows increasing warming trends since 1884.
Human Activity Driving Climate Change
- Data source: Climate Change 2021: The Physical Science Basis. Contribution of the Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5 WG2 A 2014)
- Graph displays the change in Global surface temperature from 1850 to 2020 in °C and °F
- The observed temperature rose significantly over time more sharply since 1850 than the graph of natural drivers.
Human Activity Driving Climate Change (continued)
- Data source: The Global Carbon Project
- Graph displays the trends in carbon dioxide emissions, covering the period from 1880 to 2020.
Impact of Warming
- Warming distribution at 1.5°C (2.7°F) average
- Warming distribution at 4.0°C (7.2°F)
- Global sea level history and projections
- Possible increase from Antarctic ice melt (up to 2.4 meters total)
- Currently projected range (0.3 meters to 1.2 meters)
- Shows an increasing trend in sea levels starting from 1800
More Frequent Extreme Weather With Global Warming
- Data source: IPCC AR5 WG2 A 2014
- Table displays the frequency of 10-year heavy rains, 10-year droughts , 10-year heat waves and 50-year heat waves
- Extreme weather events become more frequent with predicted global warming levels
Climate Change Performance Index
- Countries ranked by greenhouse gas emissions (40% of score), renewable energy (20%), energy use (20%), and climate policy (20%).
The Need for Renewable Energy (continued)
- Over 95% of actively publishing climate scientists agree that the earth is warming and that human activity is the cause.
- Debate is over the causes, not the evidence itself – i.e., the data shows a massive change in climate.
- Renewable Energy is focused on sustainable sources and reducing carbon (and greenhouse) emissions.
- Energy Independence is crucial for small countries like Ireland.
Solar Energy & Solar Panels (USA)
- Every day, the earth receives thousands of times more energy from the sun than is consumed in all other resources.
- If a 140x140-mile parcel of land in Arizona was covered with solar cells, the electricity needs of the entire United States could be met.
- The sunlight falling on a typical house can provide from ⅓ to ½ of the heating needs of that house.
- Today solar energy accounts for only 1% of the total renewable energy consumed in the United States.
Characteristics of Isolation
- Isolation is the amount of solar radiation reaching the earth (called Incident Solar Radiation)
- The sun's energy is created through the fusion of hydrogen nuclei into helium nuclei.
- Components of solar radiation: Direct radiation, Diffuse radiation, and Reflect radiation.
Flat Plate Collectors
- A thin flat metal plate absorbs the sun’s radiation.
- Tubes carry water into the absorber plate where it is heated by the sun and sent to a pump or fan, into storage, where it is then distributed to the living space.
Photovoltaic (PV) Cells
- Conversion Efficiency: Percentage of solar energy converted to electrical energy.
- Typical Efficiencies: Single Crystalline Silicon = 14%, Thin Film = 7%
- Innovations at NASA’s Glenn Research Center have developed high efficiency multi-junction solar cells using selenium as a bonding material between wafers.
- Selenium is transparent to light at lower photon energies (below the band gap - infrared). This allows light to move from the multi junction top cell to the silicon-based bottom cell. Efficiencies for these types can reach 40%.
Photovoltaic Cells (continued)
- Diagrams showing cell, module, and array structures.
Single-Crystal Silicon Cell Construction
- The majority of PV cells are single-crystal silicon type.
- Silica (SiO2) makes up the cells.
- Silicon is refined, purified, melted, and re-solidified to form wafers for electrical conduction.
- Doped wafers of either positive or negative type layers are used together forming a P-N junction which is the heart of a solar electrical reaction.
- Multiple cells are joined together to create arrays, sized based on sunlight in a specific area
How Does a Cell Become a Module?
- A solar cell forms the fundamental building block in a PV system.
- Solar cells will typically produce 0.5-1V of electricity.
- Modules group solar cells together, or arrays are created when enough solar cells group together.
- Structures to direct modules toward the sun, DC to AC converters, and supporting components are needed
- Components facilitate the systems use in powering various applications such as pumps and commercial sites.
The Photoelectric Effect
- The photoelectric effect is relying on the concept that light striking metals causes electrons release.
- In the p-n junction, the n-type wafer, treated with phosphorus, contains extra electrons. These electrons move into holes within the p-type layer, treated with boron, creating electricity.
- An external circuit connects electrons that flow in the n-side and then go to the p-side.
Solar Cells
- Diagram illustrates the structure of solar cells, showing n-type and p-type silicon layers, the depletion zone, electron flow, and the electrical potential.
Solar Cell P-N Junction
- Diagram shows a photon striking the solar cell and creating electron and hole pairs
- These pairs move to the n-side and p-side respectively and are collected by metal contacts
Photoelectric Effect (continued)
- Diagram shows sunlight striking a photovoltaic cell to make current
- Shows components—Boron doped (P-type), and Phosphorous doped (N-Type) silicon layers, Anti-reflection coating, Cover glass, Transparent adhesive, Front contact, and Back contact
Modern Materials
- Amorphous Silicon (non-crystalline) was the first thin film developed but suffers from low efficiency and high production costs.
- P-type Layer: Cadmium Telluride (CdTe) has potential issues with high toxicity of Cadmium and limited availability of Tellurium. CdTe cells are commonly used. The thin film is encapsulated in glass.
- N-type Layer: Cadmium Sulphide (CdS) or Copper Indium Gallium Selenide (CIGS)
In the Home
- Solar cells produce direct current (DC).
- If alternating current (AC) is needed, additional components are required.
- Solar panels, charge controller, battery storage, inverter, and AC load are some examples.
In the Home (continued)
- Components of a solar photovoltaic system: Solar Module, Charge controller, Battery, Inverter
- Solar Module converts sunlight to DC electricity
- Solar Charge Controller controls voltage and current from solar array, charge the battery, prevent batteries from overcharging or discharging
- The battery stores the electricity produced from the solar array when sunlight isn’t available
- The inverter converts DC power output from the solar array to AC power needed by appliances
Pros and Cons of Solar Electricity
- Production costs are high due to semiconductors
- Research and development is focused on reducing manufacturing costs.
- Solar energy increases energy security by reducing reliance on imported energy.
- The industry is new and high-tech, creating jobs.
- Government incentives encourage investment in alternative energy
- Transportation of hazardous materials not required across country.
- Sunlight acts as a free power source.
Pros and Cons (continued)
- PV design is versatile for many applications
- No noise or air pollution
- Minimal maintenance and long service life
- Power can be centralized (in a home) or distributed (to electric companies)
Nuclear Fusion and Fission
- Nuclear fusion combines small nuclei into larger ones, requiring immense temperatures and pressure found in stars.
- Nuclear fission breaks down large nuclei into smaller ones with the use of critical mass to sustain a reaction.
- Iron is the lowest energy nucleus and cannot be split or combined. This is important to the concept of fusion and fission.
- Isotopes like Uranium 235 and Plutonium 239 are relevant in these concepts.
Nuclear Energy – Natural Uranium
- Atomic number refers to the count of protons in an atom.
- Atomic weight/mass is the average mass of an atom, calculated using naturally occurring isotopes.
- Uranium, symbol U, has an atomic number of 92 and an atomic weight of 238.029.
- Its crystal structure and acid/base properties are relevant in determining its use.
Uranium 235 Isotope
- Uranium-235 (235U) is a uranium isotope.
- It constitutes approximately 0.72% of naturally-occurring uranium.
- It’s the only fissile isotope found naturally, capable of sustaining a nuclear fission chain reaction.
Nuclear Energy – Fission (reactions)
- Neutron hitting a uranium nucleus
- Fission into smaller nuclei with other neutrons
- Neutron chain reaction
Anatomy of a Nuclear Power Plant (PWR)
- Components like Containment Structure, Pressurizer, Steam Generator, Reactor Vessel, Turbine, Generator, and Condenser are shown
- Diagrams outline the process occurring during this type of reaction.
Fuel Processing (U235)
- Uranium Mining: Uranium is mined from the ground
- Fuel Production: Uranium mining ore is processed and converted into usable fuel.
- Power Reactors: Newly produced fuel is used in reactors to produce energy.
- Spent Fuel: Used fuel from the reactors is separated or reprocessed.
Nuclear Energy – Fission (reactor)
- The core showing the reactor vessel, control rods, and coolant system
- The use of control rods and graphite cores.
- Reactors have different variations such as CRBRP design, that are important in the context of energy creation.
Anatomy of a Nuclear Power Plant (continued)
- Shielding prevents the release of radiation
- Coolant substances transmit heat away from the reaction. Steam is created from this heat, and used to power turbines
- The steam generator converts heat into electricity using a turbine and generator.
Capacity Factor (Power Generation)
- Graph measuring monthly capacity factors for selected fuels and technologies (January 2011 to October 2013), with data for Nuclear, Geothermal, Coal, Natural gas, combined cycle, wind and Hydro.
- Different ways of generating energy can show patterns of efficiency and peaks.
Capacity Factor (Renewable Sources)
- Graph measuring monthly capacity factors (January 2011 to October 2013), with data for Waste geothermal, biomass, wind, hydro, solar photovoltaic, and solar thermal.
Global Total Primary Energy Supply, 2012
- Pie chart showing the proportions of various energy sources (nuclear, natural gas, petroleum, and biofuels) to global energy supply in 2012
Top 10 Nuclear Generating Countries, 2013
- Bar graph showing the top 10 countries in terms of nuclear power generation in 2013, in amounts of Billion kiloWatt-hours
U.S. Electricity Production, 2013
- Pie chart indicating the percentage of electricity produced in the USA from various sources in 2013, like nuclear, natural gas, coal, and hydroelectric.
Global Electricity Production (trends)
- Graph showing global energy use from 2000 to 2020, with data for Coal, Oil, Natural Gas, Nuclear, Hydro, and other renewables
U.S. Operating Commercial Nuclear Power Reactors
- Map showing operating commercial nuclear power reactors throughout the USA
- Showing electricity amounts by percentage generated by nuclear sources for the US states.
Advantages & Disadvantages of Nuclear Power
- Advantages: Clean, plentiful supply, high energy content of uranium, small fuel pellets, providing base load power, energy savings, operating costs
- Disadvantages: Initial construction costs, radioactive waste and storage, natural disasters, public perception
New (fission) Nuclear Technologies
- Breeder reactors
- Potential to extend nuclear fuel supply. They produce more fissile material than they use. Generating nuclear energy and increasing efficiency.
Breeder Reactor
- Diagram illustrating the components of a breeder reactor and its operation
Fusion Reactors (Theoretical)
- Tokamak fusion device
- Technologies including Wendelstein 7-X (W7-X) an experimental stellarator
- National Ignition Facility (NIF) uses lasers, to heat and compress hydrogen fuel
- MIT Sparc Reactor heats deuterium and tritium isotopes. It creates plasma and magnetic energy through use of a toroidal chamber
Other Forms of Renewable Energy
- Wind, tidal, hydroelectric, geothermal energy.
Wind Energy
- Diagram depicting a wind turbine, its components (blades, rotor, yaw drive, nacelle, tower, and generator), and wind direction.
Hydroelectric
- Diagram of a hydroelectric energy plant, showcasing the components like forebay, water intake, dam, penstock, turbine, generator, and water discharge.
Tidal
- Diagram of a tidal energy plant, illustrating the tidal basin, barrage, and sluice gates, and turbine.
New Technologies – The Orbital O2
- Shows how the turbine's blades turn in the tidal flow to power generators.
Geothermal
- Diagram of a geothermal power plant (flash steam power plant), depicting the production well, injection well, flash tank, turbine, electrical generator, and the Earth's internal structure (hot plume, mantle, etc).
Geothermal (continued)
- Clean energy source (mostly water vapor), renewable source
- Significant hydrogen sulfide and carbon dioxide releases are possible in certain regions.
- Drilling of wells is needed, resulting in significant initial cost.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your knowledge on the key components and advantages of solar energy systems. This quiz covers topics such as solar modules, energy independence, and challenges in solar energy production. Perfect for students and enthusiasts of renewable energy!
