An innovative approach to harnessing the wind at altitude


Hely Mill

The exploitation of wind at high altitude to produce renewable energy is
perhaps the most important challenge of these years

“Wind is Sun’s heat transformed into kinetic energy through the greatest solar collector currently available,
Earth’s atmosphere. Wind total power is estimated between 1,700 and 3,500 TW; by comparison, the whole
mankind primary energy needs are estimated at approx. 14 TW.”
Cristina Archer, Stanford University

Wind Speeds

Useful areas for traditional generators

Wind Speeds

Useful areas for high altitude wing generator

With traditional windmill we can only exploit
2% energy of the wind


Rotokite and Hely-Mill system

Rotokite and Hely Mill project aims at using wind more efficiently and effectively by implementing an adaptive wing profile rotating on their axis like the blades of a helicopter

More installation areas available: on the land and off-shore

Low costs for electricity production

Wind at only 250 m is: steadier, faster, more persistent, more energy

Winds at higher altitudes become steadier, more persistent, and of higher velocity.
Power available in wind increases as the cube of velocity.

With a proper steadiness and more predictability, high-altitude winds have an advantage over near-ground winds for generating energy purposes.

High wind energy research in history

The first industrial research to generate energy from the wind dates back to almost 100 years ago with a project by Telefunken.

The Austrialian Professor Bryan Roberts has realised a prototype of wind generator that has been called Flying Electric Generator (FEG).

Google Makani

Google Makani is trying to develop an energy system that use an aircraft  with several electric generator/engines tethered to a ground station to efficiently harness energy from the wind, generating electricity at utility-scale.

However, in the absence of important results, today only a few million euros are invested in one of the most fascinating technological challenges

Rotokite and Hely-Mill project

“No wind is favourable for those who do not know where to gobut for us who knoweven a breeze will be precious.” Rainer Maria Rilke

“First, there is the power of the Wind, constantly exerted over the globe… Here is an almost incalculable power at our disposal, yet how trifling the use we make of it.”
Henry David Thoreau (1834)

The energy from the wind at high altitude

Opinions about

Rotokite system 

“…It has the potential for opening a new path for energy conversion and could contribute to novel technological development at European level.”

European project submission response

“…in my opinion the idea is good and deserves to be developed on a European project.”

Prof. Fulvia Quagliotti, Politecnico di Torino

“…Your project sounds very interesting. I wish you all the best for the realization!”

Silas Bosco – Advance Paragliders

“…the idea is very interesting.”

Jonathan Cohn – Apco Aviation

“it is probably the best kite-based technology and I think it is much better than the systems that require computer guided flight paths…”

Mark Thompson – Technical manager UK Energy Innovation Centre

“I find your inflatable Rotokite concept particularly interesting because, not only it may be altitude scalable, but also has some advantages in terms of take-off and landing with respects to the other rotary kite concepts.”

Antonello Cherubini, Scuola Superiore Sant’Anna Pisa

The team

Giovanni D. Lanzilotti

Sequoia Application Engineer

WEC project – MIT (USA)

MoS Nuclear and Energy Engineering – Politecnico di Torino

Massimo Mangiarotti

+7 years Sequoia IT Product manager

Executive MBA – Politecnico di Milano

BS Aerospace Engineering  – Politecnico di Milano

Gianni Vergnano


Sequoia IT owner


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