What is “Green Energy”?

The words “green energy” are thrown around quite a bit these days, but I don’t think most people understand exactly what green energy is. Is it green because its renewable? Is it green because its clean?

Green energy can be many things to many people, depending on your needs and political persuasion. Green can be hydro-electric, but is it green if it damns rivers and blocks the spawning paths of fish? Nuclear power is green, creating pollution-less power for many years. But is it green if the spent fuel is deadly and a meltdown can be an ecological disaster? Modern propane and coal power plants are very clean, but are they considered green if the process of acquiring fuel for them pollutes and destroys ecosystems?

That leaves us with three energy sources: wind, solar, and solar updraft towers.

Wind turbines can produce prodigious amounts of electricity from a rather small footprint. It’s fuel is free and undepletable. Wind turbines are scalable power, you build for your current needs and add more turbines as your demands increase. Wind energy is also very clean, with no by-products or harmful exhausts. The only downside of wind energy is that wind is not constant. Its flow can be predictable, and with careful planning and research locations can be found that are not only near the power grid (to alleviate the need to build more power lines) but provide a near-constant flow of wind at speeds necessary to produce utility-scale electricity.

Solar power has seen a revival in the past few years. Home developers are offering “solar roofs” to new home buyers. These are typically at a $30,000 premium over the price of a comparable house, but there are state and federal tax credits that offset the initial cost of the solar cells. The solar roofs provide between 75% to 110% of the electricity needed to power an average energy-efficient house. The only drawback is in 20 years when the solar cells need to be replaced, the tax credits that offset their purchase price wont be in effect, so the homeowner will be stuck with a $30,000 bill to replace the cells or convert back over to strictly grid-power. Two choices I don’t care for.

Solar updraft towers are an interesting concept: utilize the greenhouse effect to heat air that in turn powers wind turbines. Clean, fairly efficient, with very few moving parts and very little need for new innovations to make them work well. They produce power on hot days, cold days with sunlight, and warm nights. The only drawback is their size. They require a very large tower, typically over 1000 feet high and a few hundred feet wide, and many acres of flat ground covered in a greenhouse. The best locations would be in deserts, but typically there are no connections to power grids in the desert areas.

I believe that there is a need for clean, renewable energy. I don’t think there is one cookie-cutter solution, though. Every region has a unique set of variables that need to be addressed in order to maximize the effectiveness of the green energy source. This is a challenge we will face in the coming years as we are transitioned to a green economy, but with proper planning and research we should be able to meet that challenge head on.

G. Grant Lowrance
Parrilla Energy

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