Solar Energy in a Nutshell Solar Energy Course 2020 Part 12 of 12

Welcome to "Solar Energy in a Nutshell". 📜Get your course certificate📜 ********************************** http://bit.ly/solar-crash-course-ipolytek SUBSCRIBE to see more courses like this one *********************************************** https://www.youtube.com/channel/UCYYX-pqg9CoVhjtC4cW4DIA?sub_confirmation=1 This is the 12th and final video in our online course on Solar Energy. At the beginning of this course, we set out to answer 6 questions on solar energy. Here's a summary of what we learned. What is the role of solar PV in the global energy supply today? What will be its role in the future? At the end of 2018, photovoltaics accounted for 2.4% of the world's electricity production. In total, solar PV produced 505 Gigawatts worldwide. The International Energy Agency (IEA) predicts that solar photovoltaics will contribute about 16% of the worldwide electricity supply by 2050. According to The Fraunhofer Institute for Solar Energy Systems, "Between 2030 and 2050, we will see 10-30% of global energy demand covered by solar PV (photovoltaics). Right now we are in an embryonic state compared to where we are going in a few decades" How does solar energy compare in magnitude with other sources of energy? According to a study conducted by The International Energy Agency (IEA) the Worldwide Demand for Energy in 2015 was 18.5 TWy/y (2015). This is eclipsed by the 23 000 TWy of Solar Energy that falls on the surface of the Earth each year. The combined total of all other renewables doesn't even come close to solar at 156.3 TWy/y. Even the combined total of all non-renewable reserves doesn't even come close at 1570 TWy. Overall, we can see that the energy we receive from the sun each year is: - more than 1240x the annual global energy demand - about 150x greater than the possible annual output of all other renewable energies - and about 15x the total of all non-renewable energy reserves How do solar cells produce electricity? A photon is absorbed by the solar cell. Its energy is given to an electron in the crystal lattice. This energy excites an electron from the P-type silicon and "kicks" it into the conduction band where it is free to move around within the semiconductor. When the electron exits the P-type silicon, it leaves its place empty. creating a "hole". An electron from a neighbouring atom moves into the "hole", leaving another hole behind. In this way, holes are propagated throughout the lattice. As this happens, electricity begins to flow in the circuit that the solar cell is connected to. Ideally, a photon with an energy equal to that of the bandgap hits the solar cell and excites an electron from the valence band to the conduction band since the "surplus energy" is transformed into heat. How efficient are solar cells today? Today, there are 3 generations of PV cells. 1. Crystalline Silicon 2. Thin-film and 3. Emerging PVs Efficiencies across the three generations vary between 10% and 46%. 1st generation mono and multi-crystalline solar cells have an average efficiency of 23%. 2nd generation thin-film solar cells have an efficiency of 18% 3rd generation printable solar cells have an efficiency of 10% whereas 3rd generation solar cells with concentration or multi junctions have an efficiency ranging from 25 to 46%. How do you size a solar photovoltaic system? Step 1. Calculate the required PV power generation based on - the annual energy consumption of the load and - the number of peak sun hours per day at 1000W/m2 (based on tables and maps available online for this purpose) Step 2. Take into account the losses found in the overall system, including those due to the conversion of direct current into alternating current. - Correct the required PV power accordingly - In general, the correction factor (derating factor) is between 0.6 - 075 Step 3. Choose a module. Correct Pmax of the module (measured at 25 Celsius to the actual operating temperature. - Use the Pmax Temperature Coeffcient specified by the manufacturer - Use the actual operating temperature at the site or, if not available, the Normal Module Operating Temperature (NMOT) shown in the specifications of the module. Music ****** Track 2: Bounce Ball by Twin Musicom is licensed under a Creative Commons Attribution license (https://creativecommons.org/licenses/...) Source: http://www.twinmusicom.org/song/255/b... #SolarEnergy #EngineeringCourse #SolarPower #WhatIsSolarEnergy #SolarEnergyOverview