Dr Rajiv Desai
An Educational Blog
Solar Technologies
Solar Technologies: Solar is the only renewable energy source which could, in principle, easily meet all the world’s energy needs. _ “I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait until oil and coal run out before we tackle that.” Thomas Edison in 1931 ____ Section-1 Prologue: Currently, our civilization consumes around 17.7 Terawatts (17.7 terajoules/second) of power taken from all sources of energy, namely oil, coal, natural gas and alternative energies such as solar, wind, hydropower and others. Fossil fuels—including coal, oil, and natural gas—have been powering economies for over 150 years, and currently supply about 80 percent of the world’s energy. The environmental ramifications of using fossil fuels, combined with their expected remaining abundance on earth places limits on how much longer we as a species can rely on them as an energy source. If […]
Desalination
Desalination: _ The history of water is equivalent to the history of the world and the history of water quality is equivalent to the history of life. —Andreas N. Angelakis _ Section-1 Prologue: All early civilizations were built on the banks of rivers. Whether it was the Euphrates in the Fertile Crescent or the Tiber in Rome, rivers gave early settlements easy access to abundant streams of fresh water, essential not only for drinking but also for irrigating crops. The availability of water was one of the biggest constraints on the growth of settlement and population size. The layout of Ancient Egypt reflected this. It stretched out like a long snake, hugging the banks of the Nile River. The invention of aqueducts by the Romans first enabled water to be carried long distances, providing the crucial utility to remote stretches of its sprawling empire and allowing populations to […]
HYDROGEN
Hydrogen: _ _ Section-1 Prologue: Primary energy sources include fossil fuels (petroleum, natural gas, and coal), nuclear energy, and renewable sources of energy. Energy carriers include electricity and heat as well as solid, liquid and gaseous fuels. They occupy intermediate steps in the energy-supply chain between primary sources and end-use applications. Energy carriers allow the transport of energy in a usable form from one place to another. Hydrogen is an energy carrier, not an energy source and can deliver or store a tremendous amount of energy. Hydrogen is the chemical element with the symbol H and atomic number 1. H is in the upper left corner of the Periodic Table. Hydrogen is the most basic chemical element — just one proton and one electron — and makes up nearly three-quarters of the mass in the universe. Stars such as the Sun are mainly composed of […]
