With the onset of climate change in the 21st century, humanity has realized that the excessive consumption of fossil fuels leads to global and irreversible consequences. And we have desperately began ...

Image caption, Hot water spewing out of a ... It stores it in the soil, plants or trees. These renewable sources of energy are much cleaner to use than fossil fuels because they do not produce ...

WHAT sources of energy are available to mankind, and how do we stand if we attempt roughly to take stock? In approaching the consideration of this subject the first thing which strikes us is the ...

All of the sources of energy heretofore considered, except the tides, we supplied by solar radiation. This fact suggests the possibility of obtaining energy directly from the sun's rays.