The power and potential of wind

Tim Iverson

(4/2019) Picture the Earth as a top spinning in circles around a table with the Sun in the middle. Dizzyingly the top spins round and round. Our individual spins make our days, while the broader circles around the center of the table make our years. As our top spins it wobbles back and forth. It ever so slightly leans this way or that before swaying back in the other direction. As our planet, just like the spinning top, leans away from or towards the sun it receives more or less direct sunlight. It’s this wobble that helps create the dynamic seasons that we experience.

Air is a gas, but it behaves like a liquid. Like liquids it takes up space, it has mass, and when a pressure or force is exerted on it moves. Imagine a filled up balloon. If you squeeze on one end it forces the air inside to the otherside of the balloon. The pressure you created causes the gas to move to where there is less pressure. Air in our atmosphere works the same way.

As air particles are exposed to direct light from the Sun they warm, become less dense, and rise. This creates an area of low pressure. As this low pressure warm air rises colder, denser, heavier air begins to flow horizontally to fill this newly created void. It’s like taking a spoonful of milk out of a bowl of cereal. As you lift the milk laden spoon upwards milk rushes into the spot you just scooped from. Remarkably, this process can occur locally or over large geographic regions - hemispheres even!

Like large rivers of air constantly seeking balance the air continuously shifts, sometimes in a gentle trickle like breeze and other times as raging white water with gale force turbulence. The National Weather Service and the National Oceanic and Atmospheric Administration (NOAA) rate March and inversely November as the some of our windiest months for the Washington, D.C. region. That’s when we’re in the middle of these wobbles causing seasonal shifts towards warmer and cooler periods. As we receive more or less light air masses are shifting to balance out these high and low pressure areas creating wind.

Wind is a powerful force. It erodes rocks, helps plants pollinate one another, aids in bird migration, and has been harnessed by people since the dawn of time. Mariners have captured and ridden the wind for nearly as long as boats have existed. Farmers have used windmills for centuries to grind grains and pump water. The Man of La Mancha, Don Quixote, himself valiantly fought them to create his own personal glory. More recently we’ve turned toward renewable energy production as means to reduce reliance on fossil fuels and foreign dependence.

According to the Maryland Energy Administration, 1.4% of electricity generated within the state in 2016 came from land-based wind turbines. That modest amount was enough to supply power to 49,000 homes. New legislation currently being worked on, the Maryland Clean Energy Jobs Act (MCEJA) of 2019, seeks to push that to 10% by 2030. Previous legislation, from 2013, authorizing two offshore wind farms, near Ocean City, MD, should be complete by 2022. Combined they will generate enough electricity to power 111,000 homes. WIth the passage of this current bill more alternative fuel sources could be coming.

Wind turbines aren’t just limited to the coasts or the mountains of Maryland. Homeowners have access to these too. Installation costs vary wildly depending on energy usage and need, but individuals can have turbines installed at home. Both federal and state tax credits are available to subsidize the cost. An additional benefit is something called net-metering. Typically energy flows one way - from the grid to your home. However, for citizens with alternative power sources attached to their homes energy can flow in both directions. If you use more than you generate you will continue to draw from the grid to compensate for your needs, and as usual you pay the utility company for what you use. If you generate more than you use energy flows from your home back into the power supply, which turns your meter backwards. What’s important about that backwards flow is that homeowners are paid for this, either through reduced energy bills or as a credit available for a 12 month period. Net metering applies to home turbines, solar panels, and geothermal heating and cooling units.

With large scale wind farms there is some cause for environmental concern. As far as land is concerned it’s relatively low impact. Wind farms are generally constructed on preexisting clear land, so it doesn’t cause much deforestation or land disruption. Wildlife presents a unique set of challenges though. Wind farms are placed where it is consistently windy, which are generally the same routes migratory birds use. Impact assessments are conducted prior to being placed and in regular intervals to determine what, if any, impact they will have and ways they can be minimized. Bird and bat deaths are unfortunate side effects. Recent efforts have been made to reduce such casualties. Radar is being used in some wind farms to track mass bird movement. If it appears the birds will come into contact or are in danger of running into the turbines they are shut down. Micro frequency emitters have also been attached to many wind turbines to direct bats away. Appropriate positioning and technology that can mitigate deaths are steps in the right direction, but ultimately will only curb avian deaths not stop them altogether. For a zero carbon emitting renewable power source society may need to take the good with the bad. As global temperatures continue to rise and energy consumption increases worldwide climate impact is of paramount concern.

There is little scientific debate that the Earth is in a warming trend, what remains is only political. Presently the notion among experts is that delayed reaction is just as costly as inaction. While the winds of March roar through we can either grasp or miss an opportunity to pull energy right out of the sky. If by catching the wind, bottling the sun, utilizing stable ground temperatures, and harnessing rivers we can reduce the production of carbon dioxide we absolutely should.