Taking a look at Project Drawdown’s solutions to climate change
Somewhere between the years 500 and 900 AD, the first windmills seen in the world appeared in Persia. Initially used for water pumping and agriculture—by direct use of the mechanical energy produced by the spinning of the blades—it wasn’t until the end of the 19th century that the mechanical energy produced by wind turbines was converted to electricity.
“Wind never blows,” writes Paul Hawken in the book Drawdown. Instead, wind is the result of the non-uniform heating of the atmosphere by the sun, combined with the rotation of the Earth. These conditions cause a pressure gradient across which air is pushed and pulled. This tide of fast-moving air travels across the blades of wind turbines, their shape resulting in differing pressures on either side of the blade. Much like how an airplane stays afloat, the pressure difference results in a lift force, driving the blades to rotate. Spinning relatively slowly, a complex gear system within the shaft increases the speed of rotation of the blades, thus dramatically increasing the energy generated.
Ranked as number two in total impact for climate solutions, wind turbines – notably onshore turbines, because large turbines are easier built on land than on water – generated 3.7 percent of global electricity in 2015. In Denmark, the wind capital of the world, wind turbines generate 40 percent of the electricity used in the country. An offshore wind farm in Liverpool owned by Lego (yes, the toy company) has such large turbines—each blade spanning almost two football fields—that it generates a household’s daily need for energy in a single rotation. Given the minimal land use of wind turbines, they can easily share space used for other needs; farms, for example, can house wind turbines with little intrusion on land for farming. New designs are currently tackling the potentially detrimental effects of wind turbines on bird migration, while issues related to unpredictable weather are countered by the proposal that widespread global use will mitigate this concern through the redirection of wind power to places in need. Perhaps, my friend, the answer really is blowing in the wind.
Selected climate change solutions compiled and ranked by Project Drawdown (for the comprehensive list, go to https://www.drawdown.org/). See the following issue for the next proposed solution
