Turn, Turn, Turn: The Power of Wind

Like solar energy, wind power is very alluring because it's so simple. It comes from wind – a clean, renewable and naturally occurring source of energy. Kinetic energy to be exact.

Kinetic energy can be turned into either mechanical energy or electrical energy. People have been using wind to do mechanical things for centuries like grind grain or pump water. This is what a windmill is used for.

A wind turbine is the proper term for the mechanism used to change wind motion into electricity. The wind blows the blades which are attached to a hub. The hub is mounted on a shaft that spins as the wind blows. A gear transmission box increases the speed of the spinning. This higher energy then travels down a high speed shaft to a generator that makes electricity.

A single smaller turbine can power a home or school, but most often you'll find turbines grouped together into wind farms. This electricity is collected at a substation, increased in voltage, and released along power lines into "the grid."

According to a groovy educational site called EnergyQuest, "The sunlight falling on the United States in one day contains more than twice the energy we consume in an entire year. California has enough wind gusts to produce 11 percent of the world's wind electricity." And another study shows that the potential of wind power on land and near-shore is over five times the world's current energy use in all forms. So I don't really feel like rooting around for the "cons" of wind energy.

But I will.

In order for turbines to work, wind speeds must be between 12-14 miles per hour. Obviously that cannot be a constant. But the solution to intermittency is that, besides storage from peak production times, electricity from different smaller sources can be aggregated into a super-grid, thereby balancing out abundances and deficiencies. The trick is to think about a web of renewable sources, not one everlasting fount.

What about the land mass a wind farm requires? It can actually be twice as productive, as this land can be still be used for agriculture. And what about the carbon footprint of wind energy? The manufacture and construction of wind farms requires the use and transport of large amounts of steel, concrete, and aluminum, but the emission released in this production can be offset in only nine months of operation for off-shore turbines.

Any other cons? While wind turbines don't need water to generate electricity, there have been instances of lubricating oils or hydraulic fluid leakage. In some cases this could contaminate drinking water. Wind turbines also seem to be bat killers.

Hmm. When weighing this against all of the pollution and environmental havoc wreaked by fossil fuels (bye-bye ice caps!), I'm not really deterred.

WEEK 3: Energy

Last week, Mayor Michael Nutter announced that a solar energy power plant will be built in the Philadelphia Navy Yard and should generate enough power to sustain about 200 homes. While this is a step forward, it also filled me with a small sense of dread. That’s a very small percentage of the Philadelphia population. Would it be enough to really make an impact? So for the next two weeks, we’re going to discuss something we’ve only mentioned briefly in previous postings: Energy. We can't really think about food, transportation, materials and waste without thinking about what makes all of these systems function.

We’ll start off with Energy Vampirism, consumer products that slowly sap out energy without you knowing, and give you some tips on how to best combat the problem. We’ll also go more in-depth on energy sources and give you the scoop, both pro and con, on solar, wind, nuclear, etc. We’ll finish up the discussion next week with a discussion on bio-fuels, such as switch grass and ethanol, and see if they really live up to the hype.

Also this week we're going to be joined by Karyn Gerred, a Philadelphia environmentalist and scenic artist. She will be regularly contributing news on green happenings in the film industry among other pertinent environmental facts. To start things off, she's gathered more recycling information, so look for an updated FAQs tomorrow!