The two basic issues with wind turbines are that they are obtrusive, imposing buildings and that they are ineffective in light breezes.
What if a turbine had a tree-like appearance and could operate in light winds?
A few blocks away from where the world’s leaders were negotiating the momentous COP21 climate change agreement in December in Paris, two prototype “wind trees” or arbres à vent, were silently producing clean energy from the light city breeze.
The trees are created by the French business New Wind, and their plastic leaves silently sway in any direction with the wind.
The leaves can catch electricity from winds as low as 8 kph, but larger industrial turbines must operate in gusts over 35 kph.
The 54 green leaf turbines on the trees, which are over 9 meters tall and 7 meters wide and can generate up to 2,400 kWh annually, can each absorb up to 5.4 kilowatts of energy. According to New Wind, the trees could power a modest, low-use business or provide half of the annual energy needs of the typical French household.
The wind system has a significant spatial advantage over solar electricity. A wind tree’s bent branches may be connected to any balcony or rooftop, but a 5.4kW solar array would require around 131 square meters of roof space.
They will initially only be accessible in France for those who want to “plant” their own tree. Each tree will cost around $35,000, however perhaps the price will go down as production costs fall down and the technology advances.
Aeolos Wind Energy, a Danish company that specializes in wind energy for homes, farms, and schools, and Urban Green Energy recently erected turbines on apartment rooftops in New York are two examples of how small turbines for individuals are gaining popularity.