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Water, Wind, and Sun

2013 March 29

By Neftali Hernandez Santiago

In Kansas City we briefly glimpsed spring before having another snowstorm come through the area.  There were a couple of patches of green before the white stuff covered everything again.  It got me thinking about diagrams in my old textbooks, the ones showing the cycle of photosynthesis and respiration.  As you know photosynthesis is the name we give to the process of converting light into energy that can be used to support plants which create their own food.  Nutrients, water and daily sunlight are almost enough to maintain their life styles.  Plants could be totally independent but they are not.  They also rely upon the wind, pollinators, and other animals to carry seeds and assist with propagation.

If someone asked me what the bare minimum for human beings to survive is, I would say food, water, shelter and clothing.  Thankfully, plants don’t only produce energy for themselves, but they share their transformed energy by producing wood, fibers and edible fruits to help us cover our very basic needs.  Plants do all these by utilizing the sun as their primary source of energy.

Our modern world, however, is full of needs beyond the basics.  Our society is maintained with many complex networks such as transportation, communications, energy supply, water and wastewater.  As part of our society we need energy to power our industries, cars, appliances, computers, tablets, and the heating or cooling of our homes.  But if we had to act like plants, just getting our needs met by the water, wind and sun, could we do it?

Currently the world human energy consumption during an entire year is 15 terawatts (10 to the 12th power watts give or take).  Each day, 89,000 terrawatts of solar radiation (energy) reaches the earth.  In a year, this totals almost 32.5 million terawatts.  Doing the math, 15 terawatts is a really, really, small percentage (in fact a decimal place with six zeros) of the energy the sun sends our way.  In fact, a professor at Stanford (Mark Z. Jacobsen) has put some numbers to it.  According to his calculations, we would need: 3.8 million (5-mega watts) wind turbines; 720,000 (0.75-mega watts) wave devices; 5,530 (100-mega watts) geothermal plants; 900 (1300-mega watts) hydro plants; 490,000 (1-mega watts) tidal turbines; 1.7 billion (3-kilo watts) roof PV systems; 40,000 (300-mega watts) solar PV plants; and 20 (300- mega watts) concentrated solar panels plants.  This sounds like a lot of Green (both figuratively and metaphorically) but lots of work is already being undertaken.

EPA has established the Green Power Partnership,  a voluntary program that encourages organizations to use green power as a way to reduce the environmental impacts associated with conventional electricity use. The Partnership currently has more than 1,400 Partner organizations voluntarily using billions of kilowatt-hours of green power annually.   The National Renewable Energy Lab, (part of the US Department of Energy) has as its goal, developing renewable energy and energy efficiency technologies and practices and transferring knowledge and innovations to address both the nation’s energy and environmental goals.  They also have great GIS data and maps relating to solar radiation.

So, can we fulfill the energy needs of modern human civilization and improve our environment at the same time as we move forward as a civilization by being more like plants?  It may be a long way off, but the math says YES.  Plants have been doing a good job of converting sunlight into energy a lot longer than humans.  For them it is easy to be green.   If we continue to find new ways to be green ourselves, someday we might not find ourselves singing Kermit’s famous song.

About the Author: Neftali Hernandez grew up in Puerto Rico and is an Environmental Scientist with EPA Region 7′s Drinking Water Branch.  He is a member of EPA’s Water Emergency Response Group and has a bachelor of science degree in biology and a masters of science degree in environmental health from the University of Puerto Rico.

Editor's Note: The opinions expressed in Greenversations are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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