Approximately seventy percent of the thermal energy generated in thermal and nuclear power plants is lost as waste heat, with a temperature below the boiling point of water. In a recent report on Science Advances, Yoshitaka ...
Stanford University scientists have invented a new kind of paint that can keep homes and other buildings cooler in the summer and warmer in the winter, significantly reducing energy use, costs, and greenhouse gas emissions.
Materials Science
Aug 14, 2023
0
152
The 1972 book "The Limits to Growth" shared a somber message for humanity: the Earth's resources are finite and probably cannot support current rates of economic and population growth to the end of the 21st century, even ...
General Physics
Jul 21, 2022
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2241
The boiling of water or other fluids is an energy-intensive step at the heart of a wide range of industrial processes, including most electricity generating plants, many chemical production systems, and even cooling systems ...
Condensed Matter
Jul 12, 2022
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518
Plastics are a part of nearly every product we use on a daily basis. The average person in the U.S. generates about 100 kg of plastic waste per year, most of which goes straight to a landfill. A team led by Corinne Scown, ...
Polymers
Apr 22, 2021
3
2301
At 100 feet long and weighing more than 100 tons, blue whales are the largest creatures to have evolved on the planet. Other whales, like killer whales, are larger than most terrestrial animals but pale in comparison to the ...
Plants & Animals
Dec 12, 2019
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141
In summer heat, cities may swelter more than nearby suburbs and rural areas. And while the size of this urban heat island effect varies widely among the world's cities, heat island intensity can largely be explained by a ...
Environment
Sep 4, 2019
3
184
(Phys.org) —New research shows that to prevent starvation at night, plants perform accurate arithmetic division. The calculation allows them to use up their starch reserves at a constant rate so that they run out almost ...
Biotechnology
Jun 23, 2013
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0
(Phys.org)—Furniture giant IKEA has announced plans to produce as much energy as it consumes by the year 2020. To achieve that goal, the company will install solar panels on all its stores and warehouses, and invest in ...
(Phys.org)—Questioning thoughts arise from a bracing study from Norway. The electric car might be a trade-in of an old set of pollution problems for a new set. Thanks but no thanks to a misguided cadre selling on the green ...
In 2005, total worldwide energy consumption was 500 Exajoules (= 5 x 1020 J) with 80-90% derived from the combustion of fossil fuels. This is equivalent to an average energy consumption rate of 16 TW (= 1.585 x 1013 W). Not all of the world's economies track their energy consumption with the same rigor, and the exact energy content of a barrel of oil or a ton of coal will vary with quality.
Most of the world's energy resources are from the sun's rays hitting earth - some of that energy has been preserved as fossil energy, some is directly or indirectly usable e.g. via wind, hydro or wave power. The term solar constant is the amount of incoming solar electromagnetic radiation per unit area, measured on the outer surface of Earth's atmosphere, in a plane perpendicular to the rays. The solar constant includes all types of solar radiation, not just visible light. It is measured by satellite to be roughly 1366 watts per square meter, though it fluctuates by about 6.9% during a year - from 1412 W/m2 in early January to 1321 W/m2 in early July, due to the Earth's varying distance from the sun, and by a few parts per thousand from day to day. For the whole Earth, with a cross section of 127,400,000 km², the total energy rate is 1.740×1017 W, plus or minus 3.5%. This 174 PW is the total rate of solar energy received by the planet; about half, 89 PW, reaches the Earth's surface.
The estimates of remaining worldwide energy resources vary, with the remaining fossil fuels totaling an estimated 0.4 YJ (1 YJ = 1024J) and the available nuclear fuel such as uranium exceeding 2.5 YJ. Fossil fuels range from 0.6-3 YJ if estimates of reserves of methane clathrates are accurate and become technically extractable. Mostly thanks to the Sun, the world also has a renewable usable energy flux that exceeds 120 PW (8,000 times 2004 total usage), or 3.8 YJ/yr, dwarfing all non-renewable resources.
This text uses material from Wikipedia, licensed under CC BY-SA
