How much land is needed to run the world on solar power Solar Energy Course 2020 Part 4 of 12

Welcome to "How much land is needed to run the world on solar power?" 📜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 4th video in our online professional development course for engineers entitled "Solar Energy." In it we discuss, How much land would we need to run the world on solar power? We'll answer this question using - a back-of-the-envelope calculation - the results of a study carried out by a renewable energy organization - and an estimate by the US Department of Energy for a solar-powered USA. This video is part of iPolytek's online course on solar energy. iPolytek, Professional Development Courses for Engineers. The Earth receives 174 petawatts (PW) from the sun in the upper atmosphere. This equates to 340 W/m2. - 29 % is reflected back to space - 48 % reaches the surface of the planet - The remaining 23% are absorbed in the atmosphere. The solar energy available for electricity production at the Earth's surface varies across the planet. It is affected by factors such as : - latitude, - season, - cloud cover - atmospheric conditions (dust, water vapour, etc) The figure above shows the amount of terrestrial irradiance falling on a surface that is horizontal to the surface of the Earth. This is known as the Global Horizontal Irradiance (GHI). This type of energy could potentially be captured by PV technology. GHI maps allow you to determine the daily and annual average amount of solar energy falling in your location in terms of kWh/m2. It is hard to imagine how big this amount of energy is. To help us understand it, let's use the world's Total Primary Energy Supply (TPES) as a point of reference. Primary Energy is the energy embodied in natural resources (e.g., coal, crude oil, natural gas, uranium) before being modified in any way by humans. The TPES is the total combined energy available from all resources worldwide: - coal, - oil, - natural gas, - biofuels, - nuclear and, - hydropower. Let's take the TPES of 2014 as an example. The Total primary energy supply in that year was 13 700 Mtoe or 159 Peta Watt-hour. - 31% of that energy was supplied by oil - 29% by coal - 21% by natural gas - 10% by biofuels - 5% by nuclear - 2% by hydro and - 2% by other sources We will see that the global TPES is only a fraction of the energy we receive from the sun on an annual basis. If the global TPES were to be supplied entirely from sunlight, a certain amount of land would be needed for the solar modules. The size of that area would largely depend on the efficiency of the solar cells used. If we assume a conservative photovoltaic efficiency of 8 %, we can show that six locations in the world, working together, would be capable of supplying the world's TPES of 159 PWh from the sun. The names of these deserts, their sizes, their annual global horizontal irradiation and the land areas required for these theoretical PV installations are listed in the Table below. This rough calculation shows that the 159 PWh of energy can be collected in these deserts without exceeding their land areas. This map shows roughly where these deserts are located. This theoretical calculation gives us an appreciation for the amount of solar energy that is available for the production of electricity. It shows that, in theory, the global TPES could be replaced entirely with solar energy using only six unpopulated locations in the world. This type of calculation has been done by numerous organisations with the same result. There is enough energy in sunlight to power the world using today's solar panels. Land Art Generator, an organization whose goal is to promote renewable energy, did this calculation by: - Assuming a solar panel efficiency of 20% (like today's solar modules) - Accounting for local electricity consumption and solar irradiation They concluded that: - an area roughly equivalent to the size of Spain would be sufficient to supply the world's TPES. The total area that would be required in 2030 (represented by a large square in the legend above) is distributed on the map according to the energy consumption and solar irradiation found in these different places. The areas shown on the map are determined by assuming an efficiency of 20% for the solar energy collection devices da solar irradiation of 2000 hours/year at 1000 Watts/m2. Although only a few squares are shown on the map, in practice, their areas would be distributed in many facilities to localize production. #SolarEnergy #RunTheWorldOnSolarPower #SolarPower #HowBigIsASolarFarm