Plant a tree, and your family won’t have to pay electricity bills for the rest of their lives… Is there such a good thing?!

Image source: sratup

One day in 2011, French engineer Jerome Michaud-Lariviere was walking in a square and saw the leaves on the roadside swaying in the slightest breeze. Suddenly, an idea flashed to him: What if he could make a tree and use the breeze to blow the leaves to generate electricity without too much wind?

Image source: dailymail

So he formed a team of engineers and after three years of research, developed a nearly 8-meter-high prototype called Wind Tree. It looks like a tree, and each branch is distributed with many small vertical wind turbine blades, swaying in the wind like leaves.

Image source: newworldwind

It is installed in the Pleumeur-Bodou commune in Brittany, northwestern France. Of course, Jerome does not want this to be the only breeze tree generator, but that every household has a tree in the yard that can generate electricity (provided you have a yard).

Image source: dailymail

When this tree was first invented, its price skyrocketed, selling for $56,000, or nearly 400,000 yuan.

Since the wind speed required for its power generation is not high, about 2 meters per second can generate electricity, it does not need to be at the seaside or grassland with strong winds, and can work normally with only a breeze that is almost imperceptible to humans. This also means that the power generation efficiency of its single leaf is not high, with a maximum of only about 300w, which is much worse than traditional wind turbine generators.

Image source: newworldwind

But thanks to the 36 leaves on each branch, they can coordinate with each other to increase power generation efficiency. Under ideal conditions, the power generation of the whole tree reaches 5868w, which can transmit 110/230v voltage. According to the official website, the electricity generated by "planting" a tree-shaped generator is equivalent to burning 864 kg of coal, which is quite environmentally friendly! As shown in the figure below, the stronger the wind, the greater the power generation of the tree-shaped generator.

Source: Literature

However, Jerome himself admitted that if he wanted to achieve better power generation efficiency, he would have to "plant" the tree-shaped generator higher, preferably about 50 meters, so that he could get more stable wind power. After all, not all benefits are guaranteed.

But tree-shaped generators also have incomparable advantages, such as a more beautiful shape than wind turbines, harmonious integration with the surrounding environment, and will not damage the scenery. Moreover, its main structure is made of lightweight materials, and the leaves are made of PVC plastic plates, which can be replaced, so it can be used for a long time.

Compared to large fan-blade turbines, the blades of tree-shaped generators are vertical turbines. They do not make loud noises when running, but swing gently like leaves, which has no effect on humans and animals.

Source: Literature

In order to cater to the aesthetic tastes of different people, there are three different colors of leaves, in addition to the ordinary green, there are also blue and orange.

Source: Literature

The prototype was soon a success. They started commercial production of tree-shaped generators in 2015 and installed several pilot projects in France, Belgium, Germany and other places. In 2017, the project won the EU Innovation Award. It was originally planned to promote tree-shaped generators worldwide before 2020, but this goal is still some distance away. Because it is too expensive...

Luxembourg, a solar-wind hybrid tree Source: New World Wind

Jerome hopes that this tree can be combined with other power generation methods, such as photovoltaic power generation, geothermal power generation and energy-saving buildings. When he invented the tree-shaped generator, he claimed that as long as you plant this tree in your yard, you will never have to pay electricity bills again. Is this true?

Image source: newworldwind

This needs to be calculated based on the wind conditions and household electricity consumption in different regions. We can assume that a household consumes 4,000 kilowatt-hours (kWh) of electricity per year, and a tree generator can run 280 days a year (assuming it runs 10 hours a day), so it needs to generate 4,000/280=14.29 kWh of electricity per day.

Assuming the weather is not so good and the 5868w mentioned above is not reached, a tree-shaped generator can generate 3.1 kilowatts (kW) of electricity, which means it can generate 3.1 kWh of electricity per hour, so it needs to run 14.29/3.1=4.61 hours per day. This means that if the average wind speed in an area is greater than 2m/s and there are at least 4.61 hours of wind per day, then a tree-shaped generator can meet the electricity needs of a family for a year.

Of course, this is just an idealized calculation. In fact, the stability and reliability of wind power generation are also affected by many factors, such as changes in wind speed, wind direction, blade wear, generator loss, etc. Therefore, tree generators are more suitable as a supplementary energy source, combined with other energy sources, to contribute to energy conservation and environmental protection.

Image source: newworldwind

Of course, the premise is that you have a yard... and you have to be willing to spend 400,000 yuan to buy a "tree"...

References

[1]https://www.newworldwind.com/windbush

[2]https://www.cleanenergy.org/blog/windtree-

Planning and production

Source: Bringing Science Home (id: steamforkids)

Author: Su Chengyu

Reviewed by Skin Magazine Editor

Editor: Yang Yaping