Anti-Solar? (Or, Exajoule what?)


Haven’t had much time in the past week to write or photograph.  My yard is full of red-winged blackbirds, blue jays and mourning doves.  Snapped these photos yesterday.  Now if we could only find the sunshine.  About the sun….

Fun fact: “Exajoule” is a real word.  (Bet you STEM scholars knew that.)

A “joule” is the standard unit of work or energy in the International System of Units (SI), equal to the work done by a force of one newton when its point of application moves through a distance of one meter in the direction of the force: equivalent to 10 7ergs and one watt-second.  (  So, in super simple terms, a joule is a way of measuring energy.  (Smart people feel free to add comments to this post helping us mere mortals to understand joules and exajoules.)

An “exajoule” is a wicked lot of joules.  More technically, and thanks to
Exajoule. The SI prefix “exa” represents a factor of 1018, or in exponential notation, 1E18. So 1 exajoule = 1018 joules. The definition of a joule is as follows: The joule (symbol J, also called newton meter, watt second, or coulomb volt) is the SI unit of energy and work.
As I said, an exajoule is a wicked lot of joules.
How did I happen upon that word?  Reading about solar power, which I was doing in part because the Maine Public Utilities Commission has just adopted the most aggressive anti-solar rule in the nation and so I’m educating myself about this pressing issue.  And because I was standing in the kitchen belting out “The Sun Will Come Out Tomorrow” while gazing into my foggy backyard wondering if the sun really will come out tomorrow.
I decided I’d better write my legion of admirers (all two of you) a quick post before I get on with the day.  And what more interesting way to get through a dreary day than focus on what we can’t see – the SUN!  In looking for interesting facts about solar energy I happened upon and found myself in the world of exajoules while reading the following:
Solar has Incredible Potential

If we add the amount of solar energy that is absorbed by the Earth’s atmosphere, land and oceans every year, we end up with approximately 3,850,000 EJ (exajoules or 10^18 joules).

To put it in more understandable terms, this amount of energy is equivalent to:

  • 2.7 million earthquakes of the same size as the Tohoku earthquake in Japan (2011).
  • 40 000 times the total energy consumption in the United States
  • 8 000 times the total consumption in the whole world.
  • About 40% of the energy that is required to heat the entire volume of water we have on Earth by 1°Celsius

I didn’t get any further in this article (“5 Mind-Blowing Solar Energy Facts”) because my mind got stuck on exajoules in this first fact.

Interested in learning more about solar energy but don’t want to ever read about exajoules again?  No problem!  Start here:

The sun will come out.  But maybe not until Saturday.  Just stick out your chin and grin in the meantime.


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