Renewable Energy Engineering Module - Semester I PDF

INTERNATIONAL & ACCESS FOUNDATION PROGRAMMES ENGINEERING MODULE - SEMESTER I ELECTRONIC & ELECTRICAL ENGINEERING PART 11 RENEWABLE ENERGY Dr Nevan Bermingham THE NEED FOR RENEWABLE ENERGY All fossil fuel reserve and consumption d...

INTERNATIONAL & ACCESS FOUNDATION PROGRAMMES ENGINEERING MODULE - SEMESTER I ELECTRONIC & ELECTRICAL ENGINEERING PART 11 RENEWABLE ENERGY Dr Nevan Bermingham THE NEED FOR RENEWABLE ENERGY All fossil fuel reserve and consumption data from CIA World THE NEED FOR RENEWABLE ENERGY http://climate.nasa.gov/evidence/. THE NEED FOR RENEWABLE ENERGY CLIMATE CHANGE 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 climate changes. The data is clear – the climate is changing and it will impact on our species - conspiracy theories and science denials do nothing to fix the issue There is a very strong correlation with human activity, but its more difficult to prove causality Technology is the key to solving this issue THE NEED FOR RENEWABLE ENERGY Global sea level rose about 17cm 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 1970’s 20 warmest years having occurred since 1981 and with all 10 of the warmest years occurring in the past 12 years Both the 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 HUMAN ACTIVITY DRIVING CLIMATE CHANGE DATA SOURCE: CLIMATE CHANGE 2021: THE PHYSICAL SCIENCE BASIS (PDF). CONTRIBUTION OF WORKING GROUP TO THE SIXTH ASSESSMENT REPORT OF THE INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE HUMAN ACTIVITY DRIVING CLIMATE CHANGE DATA SOURCE: THE GLOBAL CARBON PROJECT THE IMPACT OF WARMIN G DATA SOURCE: BASED ON CMIP6 MULTI- MODEL MEAN CHANGES. THE IMPACT OF WARMING DATA SOURCE: U.S. GLOBAL CHANGE RESEARCH PROGRAM 2017 THE IMPACT OF WARMING DATA SOURCE: "CHAPTER 19: EMERGENT RISKS AND KEY VULNERABILITIES" (PDF). IPCC AR5 WG2 A 2014. PP. 1039–1099. THE CLIMATE CHANGE PERFORMANCE INDEX RANKS COUNTRIES BY GREENHOUSE GAS EMISSIONS (40% OF SCORE), RENEWABLE ENERGY (20%), ENERGY USE (20%), AND CLIMATE POLICY (20%). THE NEED FOR RENEWABLE ENERGY 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 about sustainable sources and reducing the carbon emissions (and greenhouse gasses) Energy Independence is important for small countries like Ireland SOLAR ENERGY & SOLAR PANELS A FEW FACTS (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 1/3 to 1/2 of the heating needs of that house. Today solar energy accounts for only 1% of the total renewable energy consumed in the United States  Sunlight is the catalyst of the reaction. The output current of this reaction is DC (direct) and the amount of energy produced is directly proportional to the amount of sunlight put in. Cells only have an average efficiency of 20%, but new cells are reaching 40% efficiency. Solar constant = 1,350 Wm2 At the earth's surface, the nominal value of the solar constant is ≈ 880 W/m2 (due to light absorption, scattering, etc) CHARACTERISTICS OF ISOLATION Isolation is the amount of solar radiation reaching the earth. Also called Incident Solar Radiation. The sun’s energy is created from the fusion of hydrogen nuclei into helium nuclei. Components of Solar Radiation:  Direct radiation  Diffuse radiation  Reflect radiation FLAT PLATE COLLECTORS A thin flat metal plate is used to absorb 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 and distributed from there to the living space. PHOTOVOLTAIC (PV) CELLS Conversion Efficiency – the percentage of solar energy shining on a device that is converted into electrical energy Typical Efficiencies Single Crystalline Silicon = 14% Thin Film = 7% Innovators at NASA's Glenn Research Center have developed a high efficiency multi-junction solar cell that uses a thin interlayer of selenium as the bonding material between wafers. Selenium is a unique semiconductor in that its transparent to light at photon energies below the band gap (infrared), enabling light to pass from the multi- junction top cell to the silicon-based bottom cell = 40% Efficiencies. PHOTOVOLTAIC CELLS  SINGLE-CRYSTAL SILICON CELL CONSTRUCTION The majority of PV cells in use are the single-crystal silicon type. Silica (SiO2) is the compound used to make the cells. It is first refined and purified, then melted down and re- solidified so that it can be arranged in perfect wafers for electric conduction. These wafers are very thin. The wafers are doped with either a negative type layer or a positive type layer respectively. Used together these two types treated of crystalline silicon form the p-n junction which is the heart of the solar– electrical reaction. Many of these types of cells are joined together to make arrays, the size of each array is dependent upon the amount of sunlight in a given area. HOW DOES A CELL BECOME A MODULE? A solar cell is the basic building block of a PV system. A typical cell produces.5 to 1V of electricity. Solar cells are combined together to become modules or if large enough, known as an array. A structure to point the modules towards the sun is necessary, as well as electricity converters, which convert DC power to AC. All of these components allow the system to power a water pump, appliances, commercial sites, or even a whole community. THE PHOTOELECTRIC EFFECT The photoelectric effect relies on the principle that whenever light strikes the surface of certain metals electrons are released. In the p-n junction the n- type wafer treated with phosphorus has extra electrons which flow into the holes in the p-type layer that has been treated with boron. Connected by an external circuit electrons flow from the n-side to create electricity and end up in the p-side. SOLAR CELLS SOLAR CELL P-N JUNCTION. PHOTOELECTRIC EFFECT MODERN MATERIALS Photovoltaic materials used in thin film technology include: Amorphous Silicon - amorphous (non- crystalline) silicon was used in the first thin film to be developed, suffers from low efficiency levels and high production costs. P-TYPE LAYER: Cadmium Telluride - has potential problems with the high toxicity of Cadmium and the limited availability (at present) of Tellurium. This method is in current use, with the thin film encapsulated in glass, which will seal in the Cadmium in the event of a fire. N-TYPE LAYER Cadmium Sulphide or Copper https://www.youtube.com/watch?v=1gta2I IN THE HOME Solar cells produce direct current (DC), therefore they are only used for DC equipment. If alternating current (AC) is needed for AC equipment or backup energy is needed, solar photovoltaic systems require other components in addition to solar modules. IN THE HOME The components of a solar photovoltaic system are: Solar Module is the essential component of any solar PV system that converts sunlight directly into DC electricity. Solar Charge Controller regulates voltage and current from solar arrays, charges the battery, prevents battery from overcharging and also performs controlled over discharges. Battery stores current electricity that produces from solar arrays for using when sunlight is not visible, night-time or other purposes. Inverter converts DC power output of solar arrays into AC for AC appliances.  PROS AND CONS OF SOLAR ELECTRICITY Expensive to produce because of the high cost of semi- conducting materials, which could be avoided by reducing manufacturing costs. The PV Manufacturing Research and Development Project focuses on increasing manufacturing capacity so that the cost of manufacturing will decrease. They aim to achieve break even costs. However, solar energy contributes positively to the nation’s energy security because it is produced domestically, reducing reliance on energy imports. The industry is still relatively new and extremely hi tech allowing for the creation of more jobs in the American market. The government has many incentives programs to encourage investment in forms of alternative energy. Does not require the transportation of hazardous materials across country. Sunlight is a free abundant source!  PROS AND CONS (CONT.) PV can be designed for a variety of applications No noise or air pollution Require minimal maintenance and have long service life. Power can be either centralized in individual homes or distributed by electrical companies. NUCLEAR FUSION AND FISSION  Nuclear Fission  Nuclear Fusion Large nuclei into Small nuclei into small large Critical mass to Immense sustain temperature and pressure Two isotopes we 235 239 Core of stars U use Pu Iron is the “dead end” of both fusion and fission – it is the lowest energy nucleus and cannot be split or fused. NUCLEAR ENERGY – NATURAL URANIUM atomic number: The number of protons in an atom. atomic weight/mass: The average mass of an atom, taking into account all its naturally occurring isotopes. The sum of the number of protons and the number of neutrons in an atom URANIUM 235 ISOTOPE Uranium-235 (235U) is an isotope of uranium making up about 0.72% of naturally occouring uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a fission chain reaction. It is the only fissile isotope that is primordial and found in relatively significant quantities in nature. NUCLEAR ENERGY - FISSION Chain Reaction ANATOMY OF A NUCLEAR POWER PLANT Source: NRC FUEL PROCESSING U235 Source: NRC NUCLEAR ENERGY - FISSION NUCLEA R ENERGY – FISSION In reality what a reactor core looks like ANATOMY OF A NUCLEAR POWER PLANT Fuel: The fissionable material used in the reactor is called as fuel. The commonly used fuels are Uranium, Plutonium or Thorium. It can be U-235, U-238, Pu-236 or Th-232. Uranium is mostly preferred as it has high melting point. Moderators: Only neutrons of a fairly low speed should be used to have controlled chain reaction. To slow down the speed fast moving neutrons produced during the fission process, moderators are used. Moderator reduces the speed of the neutron by absorbing its energy but not absorb neutron. Graphite, Heavy water and Beryllium are common moderators. Control Rods: These rods absorb neutrons and stop the chain reaction to proceed further. These are made up of steel containing a high percentage of material like cadmium or boron which can absorb neutrons. When control rods are completely inserted into the moderator block then all the neutrons is absorbed and reaction comes to halt. Source: NRC ANATOMY OF A NUCLEAR POWER PLANT Shielding: Shielding prevents radiations to reach outside the reactor. Lead blocks and concrete enclosure that is strong enough of several meters thickness are used for shielding. Coolant: The coolant is substance in a pipe to the steam generator where water is boiled. This is where heat-exchange process occurs. Heat is absorbed by the coolant that is produced in the reactor. Typical coolants are water, carbon dioxide gas or liquid sodium. Turbines: Steam produced in the boiler is now passes to a turbine. The force of the steam jet causes the turbine to rotate. Heat energy (steam) is converted to mechanical energy (moving turbine). Generator: The generator consists of coils that change the mechanical energy into electric energy. The turbine moves and the change in magnetic flux cause electricity. This is transmitted to substations for distribution of electric power. Source: NRC CAPACITY FACTOR (POWER GENERATION) CAPACITY FACTOR (RENEWABLE SOURCES)  GLOBAL TOTAL PRIMARY ENERGY SUPPLY, 2012 Nuclear provides about 10.8% of global electricity generation. Natural Gas Coal 21.27% 29.01% Petroleum Nuclear 31.45% 4.80% Hydropowe r 2.36% Geothermal Biofuels , Solar, etc. and Waste 1.06% Data: International Energy Agency 10.05%  TOP 10 NUCLEAR GENERATING COUNTRIES, 2013 800 700 600 Billion kiloWatt-hours 500 400 300 200 100 0 s ce ia y e s th ina da an ine o m en at a n us o u h a a gd d t Fr S C an m kr e d S R a, C er U K in S w e G te or d ni K te U ni U Data: Energy Information Administration  U.S. ELECTRICITY PRODUCTION 2013 Geotherma Petroleum l 0.41% Solar 0.66% 0.23% Hydroelectric Other 6.52% 0.61% Nuclear 19.44% Biomass 1.48% Wind 4.13% Coal Natural 39.08% Gas 27.44% Data provided by US EIA Net Generation by Energy Source The NEED Project  GLOBAL ELECTRICITY PRODUCTION "GLOBAL CARBON BUDGET 2019". EARTH SYSTEM SCIENCE DATA Data provided by US EIA Net Generation by Energy Source NUCLEAR ENERGY PRODUCTION Percent Electricity Generated by Nuclear Power VT 73.76% MN 20.52% NH 56.72% NE 20.06% SC 56.07% MS 19.91% NJ 51.15% AR 18.38% IL 49.16% WI 18.32% CT 47.29% LA 16.40% VA 41.46% KS 16.14% MD 37.73% OH 12.43% TN 36.66% FL 12.00% PA 35.23% MA 11.96% NC 34.49% IA 9.39% NY 32.97% MO 9.11% AZ 28.34% CA 8.98% GA 26.90% TX 8.91% MI 26.74% WA 7.24% AL 26.70% Data: Nuclear Energy Institute ADVANTAGES & DISADVANTAGES OF NUCLEAR POWER  Clean   Initial construction Plentiful Supply costs  High energy content in  Radioactive waste uranium byproduct Small fuel pellet  Storage Can provide base load power  Natural disasters Energy savings in  Public perception transportation  Operating cost is low after construction The NEED Project NEW (FISSION) NUCLEAR TECHNOLOGIES  Breeder reactors are a type of nuclear reactor which produce more fissile materials than they consume.  They are designed to extend the nuclear fuel supply for the generation of electricity  Mistakenly called a potential renewable energy source, but Breeder Reactors have the ability to make nuclear fuels quite sustainable Image courtesy of Department of Energy The NEED Project BREEDER REACTOR Image courtesy of Department of Energy FUSION REACTORS (THEORETICAL) TOKAMAK FUSION DEVICES  FUSION REACTORS (THEORETICAL) Wendelstein 7-X (W7-X) reactor An experimental stellarator (nuclear fusion reactor) built in Greifswald, Germany, by the Max Planck Institute of Plasma Physics 2015 National Ignition Facility (NIF) Reactor NIF uses lasers to heat and compress a small amount of hydrogen fuel with the goal of inducing nuclear fusion reactions. It rapidly collapses a small amount of fuel so the pressure and temperature reach fusion-relevant conditions. NIF does this by heating the outer layer of a small plastic sphere with the  FUSION REACTORS (THEORETICAL) MIT Sparc Reactor The Sparc reactor proposed by MIT isn’t dramatically different than other tokamak fusion devices from previous experiments. It starts with deuterium and tritium, both isotopes of hydrogen. When heated to high temperatures, it forms a plasma that the reactor confines within a magnetic field encircling the toroidal chamber of the reactor. The high heat and pressure cause some of the atoms to undergo fusion and release energy. https://www.extremetech.com/extreme/280265-mit-plans-new-fusion- reactor-that-could-actually-generate-power OTHER FORMS OF RENEWAL ENERGY Wind Energy Tidal Energy Hydroelectric Energy Geothermal WIND ENERGY HYDROELECTRIC TIDAL NEW TECHNOLOGIES…. THE ORBITAL O2 Electricity to meet the demand of around 2,000 UK homes – 2 Mega Watts of Power Generation from the Tides GEOTHERMAL  Clean (mostly releases water vapor) Renewable (core heat is mostly from decay of radioactive isotopes, such as potassium-40 and thorium-232) Can release hydrogen sulfide and carbon dioxide In certain areas, drilling is needed (large set up costs) Can “dry up” over time. Shown to cause “Micro- Quakes” ANY QUESTIONS?