The Final Word by Chuck Swann

The Final Word by Chuck Swann

The sunlight striking the earth's surface in just one hour delivers enough energy to power the world economy for an entire year. Got that? Read it again. It is a grandiose statement, but it is factual.

Now for the qualifiers: a tad over 71% of the earth's surface is covered by water, the great majority of it salty, of course. A tad under 29% of the surface is dry land. And much of that land is very, very dry, which means that very few people live there.

Very dry locales that spring to mind include the Saharan, Sahelian and Mongolian deserts and perhaps even a great chunk of the American Southwest. Chile's 1,000 kilometer-long great northern Atacama Desert, said to be the driest on earth, gets enough daily sunshine to power the entire country--if there was any way to distribute that energy to the country's central and southern temperate regions. Sunshine on the Atacama is unrelenting; on temperate regions it is intermittent.

Many developed and developing nations around the world have installed solar capacity to reduce dependence on fossil fuels. Solar power plants use one of two technologies: Photovoltaic systems use solar panels to convert sunlight directly into electric power. Concentrated solar power plants use solar thermal energy to make steam, which is then converted into electricity by a turbine.

As of early 2017, the largest solar power plants in the world are the 850 MW Longyangxia Dam solar park in China for photovoltaics and the 377 MW Ivanpah Solar Power facility in the US for concentrated solar power. Most operational CSP installations are located in Spain and the USA, while large solar farms using photovoltaics are being built in an expanding list of nations.

Chuck Swann is Senior Editor of Paperitalo Publications.