High altitude wind: the long awaited energetic “miracles” [1]

Massimo Ippolito [2] - KiteGen Research s.r.l. [3]     August 2016


KiteGen is certain to have seized the holy grail of sustainable energy. We registered more than 40 international patents, have been cited in more than 350 scientific publications[4], and, from different points of view, corroborate and complete our thesis. KiteGen is the only Italian company (and the only one focused on energy innovation in the world) in 2015 Cleantech 100 Company's "ones to watch" (no Italian company is present in 2016 list). We have been granted the ENI award[5]. These awards and recognitions were granted after technical diligences, and the various proofs of concept are real, public and documented. But this technology has not yet breached into the system, we still lack support from institutions, and The Netherlands is the only country offering academic courses on this subject. High altitude wind energy is a grand project needing to step up to a completely new level, from research to industry, with the entire onus, as well as the impact on employment, implied by this change. In 2006, KiteGen manufactured a generator already competitive, even in its first stages of development, with solar panels for both costs and energy supply reliability. Nevertheless, we got to be helpless witnesses while all institutional support went to conventional wind power sources and photovoltaic. It's easy to figure out the charismatic role and enthusiastic growth this new energy device could have had, had it been granted any kind of start-up support. KiteGen kept up working on design and validation on its own, a task for a team much bigger than the one that actually accomplished it. Now theoretical basis, prototypes, intellectual property, technology package, are real assets on which the restart will be based, and with which we can spread the world of the change it could bring. KiteGen is an opportunity Italy and Europe cannot pass up, due to their serious and persisting energy deficit. Seems like the idea that energy is a "problem we cannot solve, yet crucial for every country and their economy" gets stronger by the day. We here try to propose again the rationale of KiteGen Project, the state of art, and the trouble we met while trying to spread that, which is not just an opportunity anymore, but, for anyone versed enough in energy sector, without doubt the primary energy source that will feed the future of civilization.





We Need Energy Miracles By Bill Gates | June 25, 2014

[2] m.ippolito@kitegen.com

+39 348 0194813

[3]KiteGen Research s.r.l.

cso Lombardia 66/c

San Mauro Torinese

+39 011 9415745


[4] https://scholar.google.it/scholar?hl=it&q=kitegen&btnG=&lr=




ftp://kitegen.com/pdf/kitegen_status_art_file/image004.jpgKiteGen Research (proponent and leading organization) is working with specialized partners on the KG Stem project for the development of a 3MW tropospheric wind generator.

Sequoia Automation is an industrial engineering firm specializing in the design of software and electrical/electronic, control and mechanical systems. It has conducted numerous research and development activities in the past and has also managed European funded research projects. Its involvement in numerous activities in the field of energy has given it a profound knowledge of the industry. These include: control and synchronization of gas turbine generators, robotic maintenance of high voltage lines, autonomous energy systems, supercapacitors, inertial platforms and energy regeneration systems in vehicles. Moreover, as a company operating at the service of KiteGen, Sequoia has the advantage of forty years of experience as a mechatronics and R&D design firm. It has accumulated the extensive multidisciplinary knowledge required for the design and construction of next-generation systems that integrate various fields of expertise. The company’s assets include artificial intelligence systems, physics and fluid dynamics engines, inertial platforms, electric vehicles and nonlinear multi-predictive numerical controls, parallel kinematic robots and supercapacitors.

Since 2008, Sequoia has been almost exclusively managing the ambitious and complex KiteGen® project centred on tropospheric wind power. It has adopted this as a mission as a result of meetings at the highest levels of European research and with key historical figures in Italian electrical energy, who expressed their support for Sequoia’s commitment as an entity certainly capable of meeting the challenge. The objective has gone beyond a mere corporate project to become a profoundly ethical and collective mission. With this attitude, Sequoia has invested several million euros over time in the industrial training of hundreds of candidates and interns, with the conviction of being able to develop around them the professional offer necessary for the project. The success of this strategy surpassed all expectations, generating hundreds of business initiatives worldwide that are ready to collaborate in a multinational initiative. 

The activity conducted so far has produced a substantial “technology package” describing the innovation in detail, which has gained significant value from the addition of the physical and experimental validation of all the steps leading to the distillation of the knowledge. This has made possible the industrialization and production of the generators in their final form, with a predeterminable time to market, a result that has changed the current corporate mission.

Other industrial companies specialized in complementary fields have recently joined Sequoia.

These include a composite materials company with twenty years’ experience in the field of advanced composites for the aeronautics sector. Throughout its years of activity, the company has experienced continuous growth in terms of turnover and staff. This has been possible thanks to investments in equipment and facilities that have enabled it to gain important contracts in the aeronautical sector and become a supplier for large aircraft manufacturers, such as Boeing.

Thanks to its elevated skills and experience in the field of advanced composites, it has acquired new contracts in both the aerospace and the industrial sector, where structures and components that were once made of metal are now being replaced with much lighter and more durable composite parts. The markets it serves ranges from the aeronautic and automotive sectors to automation, printing, packaging, railways and energy.

The scope of the specialist composite company is to support, produce and industrialize products that require improvement in terms of technology and performance. This can be achieved by replacing traditional materials with advanced composite materials, or by designing components made with these new technologies. The KiteGen wing, which is a completely new and extreme object, can reap the benefits of this extensive experience, as well as the specialized equipment designed for working on large monolithic composites.




With the exception of hydroelectric power, which is, however, limited in its application due to the relative scarcity of sites and viable conditions, humanity has not yet managed to identify new sources of renewable energy that are not dependent on subsidies. These contribute to the deterioration of the economic downturn, reducing consumptions and driving away various industrial initiatives from the country, together with the respective jobs, due to their distorting effect on energy prices. Within the energy sector, the project’s objective is the industrialization and management of the production of wind generators that can extract energy from the troposphere. This extends up to about 9,000m above sea level and has been shown by comparative analyses to be the cleanest, most concentrated and most abundant natural energy resource. For this purpose, our research has examined technological methods to make use of this mechanical energy resource, equivalent to over 200 times the current basic needs of human kind. The work has focused on architecture, technologies and materials for the development of these wind machines, and solutions have emerged with dramatic improvements in performance compared to existing methods. These take advantage of the wide availability of new mechatronic intelligence in order to exploit the kinetic energy of high altitude winds.

This produces the following advantages:

* Particular lightness and dematerialization of the generators (only 20 tons as compared to 1,500 tons for an equivalent wind turbine), thus greatly facilitating production, installation and maintenance logistics.

* Access to substantially larger wind front areas compared to traditional wind turbines, allowing a much greater quantity of energy to be harvested, even with winds considered not very productive.

* Access to altitudes where the wind has greater intensity and consistency than that available to wind turbines.

* Modulable (non-intermittent) baseload behaviour that multiplies the intrinsic value of the energy produced.

The concepts developed to meet these requirements, and the respective physical and experimental validations, have led to the filing of 40 patent families acknowledged as innovative and industrially applicable, with over 3,000 extensions worldwide. This provides the knowledge base for a desirable and radical transformation of wind energy production processes and the entire wind energy sector, as well as a reduction in energy production costs by a factor of 10, with LCA studies showing an ERoEI 30 times greater than that of wind turbines.

The system is composed of three main parts: a generator robot based on the ground, strong, lightweight cables of sufficient length to reach the typical operational altitudes (1,000-2,000 m), and an arched semi-rigid, tensile structural power wing large enough to provide a tensile force of 300 kN, with adequate efficiency to allow cross wind flight at 80 m/s. After extensive studies on the cable requirements, the fatigue behaviour induced by the winches and the properties of the most innovative fibres on the market, the choice fell on ultra-high-molecular-weight polyethylene (UHMWPE). This fibre fully meets the specifications for durability and strength. The generator on the ground has two lines of alternators that operate pulleys and winches on which the cables are wound, with the wing connected to the opposite ends by means of bridles. The generator robot has a pair of opening mobile arms with 2 degrees of freedom for the purpose of keeping the wing suspended. Takeoff can be performed by exerting sufficient traction on the cables or by rotating the arms to overcome stall speed through centrifugal force. During takeoff the wing moves away tracing figure 8 trajectories (lemniscate) and rises up until it finds sufficient wind (cut-in – about 4 m/s) to produce a nominal force of 150 kN on each cable. At this point the cables can unwind at a speed equal to the wind speed less the cut-in speed in order to maintain a constant nominal force. Thus there is a power on each cable of 150*v kW, reaching the nominal 3 MW when the unwinding speed v equals 10 m/s (wind speed of 14 m/s). This mechanical power is transformed into electrical power by alternators connected to pulleys and reels. When the cables are completely unwound, the sideslip manoeuvre is performed (one of the innovations described in the patents), which allows the cables to be rewound differentially (one of the cables is kept a few dozen metres shorter than the other), causing the wing to assume the shape of a flag (thanks to its articulated rigidity) and lose its aerodynamic properties to minimize resistance during the recovery of the cables.

During this phase the alternators act as motors, with an energy consumption of 1% of that produced in the active phase. Once the wing has returned to a minimum altitude (programmed based on wind conditions) the length and tension of the cables is rebalanced, the wing recovers its natural arc shape and aerodynamic properties, and once more provides the necessary nominal force and mechanical power to perform further cycles. The major innovation factors contained in the patents include devices designed to increase the flight stability and control, such as radio controlled ailerons and bridles with programmed elasticity to continuously optimize the wing’s angle of attack, as well as solutions to reduce the resistance of the cables, giving them an aerodynamic profile.

Other highly innovative aspects include the use of inertial platforms (an accelerometer, gyroscope, magnetometer and altimeter integrated into a miniaturized device). These devices, positioned on the wing and on the mobile parts of the ground-based generator and linked to the control unit via radio, allow the computer to create accurate real-time dynamic models of the mechanical and wing parts through the application of mathematical operators and Jacobian matrices, to predict their behaviour in real time and adjust stresses and propagation on the various parts. For example, a gust of wind that would cause a violent increase in the force transmitted by the wing through the cables, with the impulse propagated along the cables at the speed of sound, would be detected by the accelerometers and transmitted to the ground at the speed of light. This allows stability of control and dampening, e.g. prompt release of the cables to neutralize the incoming impulse.



The “Wings & Power” project, co-financed by the region of Piedmont with European funds (but reduced from the original €7 million to less than €3 million due to the institution’s financial needs) and successfully concluded in March 2016, contributed in part to the development of the technological solutions based on the inventive teaching of the patents and the consequent achievement of TRL7. Eighty components containing the main innovation elements featured in the patent portfolio have been designed, manufactured and validated (now grouped into 10 machine sub-assemblies). Recognition of this level of technological advancement was confirmed by the signing of an important contract with a chemical multinational for the purchase of hundreds of generators, subject to the subsequent achievement of TRL 9.

The steps to be taken in this respect are the establishment of a production line capable of manufacturing the product with industrial quality and of re-testing it in operational conditions to meet the conditions of the existing contract and other contracts, which in all likelihood will be easily obtained through with establishment of an energy production track record. It offers reliability, safety and economic sustainability only possible for a product with the highest industrial standards. The region of Piedmont has numerous other outstanding industrial realities capable of handling partial or entire sub-assemblies and providing the necessary quality for their production. The proposed initiative, in addition to distributing the innovations produced during the R&D phase among local companies, which can also have repercussions on various other products, together with the unprecedented performance of the generator, will help create linked activities and a subcontracting sector engaged in the production of thousands of machines per year for export all over the world, with the recruitment of tens of thousands of workers with the medium and high levels of specialization typical of the aerospace industry.




The project can be considered a fusion between mechatronics and aerospace. This combination often encounters a cognitive bias that tends to raise or relegate it to the sphere of basic research, although efforts to provide information and updates soon lead to recognition of its industrial significance and readiness. The basic research was completed thanks to intense collaboration between Sequoia, some hi-tech companies, and researchers and interns from the Universities of Turin, Milan, Leuven, Stuttgart, Delft, Wuppertal, Stanford, etc., and initially catalysed by research funding from the region of Piedmont. In the event of its programmatic adoption, the impact of this new wind technology on the socio-economic system could be successfully replicated on international markets, providing a valuable response to the ongoing economic crisis and decline in employment, since energy, and only that with low production costs, is what ultimately drives human progress.

The power wing is the focus of the collaboration with our composite manufacturing partner company. In the economy of the generators, this is a consumable material, like the cables, with an envisaged annual rate of replacement. These circumstances and opportunities outline a synergistic future, where the robot generators are installed in production sites and the periodic supply of wings links the power generation companies operating in the local area with the firms manufacturing the machines and the wings. A business model can be envisaged that includes maintenance and the supply of consumables.



In terms of publications, KiteGen has given rise to over 300 documents and active collaboration with dozens of academic institutions. Istituto Sant’Anna of Pisa and the University of Bologna have prepared an orientation document:

Airborne Wind Energy Systems: A review of the technologies

    Antonello Cherubini(a), Andrea Papini(a), Rocco Vertechy(b), Marco Fontana(a),

    a) PERCRO SEES, TeCIP Institute, Scuola Superiore Sant׳Anna, Pisa, Italy

    b) Department of Industrial Engineering, University of Bologna, Italy

KiteGen undoubtedly represents a new development in the field of energy, with a feasibility, scalability and merit factor that can be calculated and assessed in advance with great reliability, as can the steps and investments required to implement it as an energy support at the service of the community, with analytical data already available in sufficient detail from KiteGen. Unfortunately, due to the totally new and multidisciplinary nature of the system, the institutions cannot provide the necessary and comprehensive competences for its systematic adoption, both in terms of investment and of research. This makes it difficult to establish a complete supply chain and the procurement of human resources capable of acquiring the necessary knowledge and determination. From a close analysis of the underlying dynamics, three types of obstacles can be seen that delay the emergence of the technology, which in the light of the current and not-so-bright scenario of typical renewable sources remains an obvious and essential source.

The first obstacle is undoubtedly due to the particular interests of certain economic sectors, which are opposing the KiteGen concept while they can, with a considerable financial commitment. Surprisingly, these are parties involved with sources currently considered as renewable and that benefit from support policies for their deployment. KiteGen is the first ever source which, once the initial technological learning phase is completed, will no longer need aid but will itself become a powerful economic engine, dramatically abandoning the subsidy policy.

The second obstacle that involves KiteGen is connected with politics and ideological organizations. Surprisingly, these are groups related to scaremongering over climate, the environment, overpopulation and dwindling resources. Knowing KiteGen very well, they should be supporting it instead of opposing it and feeding on the consensus that comes from an alarmist and superstitious attitude. They become increasingly pervasive, getting considerable power and economic benefits, as long as the various alarms remain without effective solutions, and KiteGen undoubtedly represents a threat to these privileges.

The third one has already been mentioned, namely the difficulty of grasping a highly multidisciplinary and unfamiliar concept.  KiteGen would be able to address these difficulties effectively if attitudes more open to dialogue could be established between the evaluation sessions and the project. To this end, a review is provided below for better prior clarification of the main points confirming the project’s technical feasibility, which, from our experience, tend to disorient those unfamiliar with the design and sizing of the generating machines and the wing in the light of the design specifications:

Lift, flight speed and axial load of the arched semi-rigid wing

Although this is the topic most developed at the level of scientific literature, with substantial formalization and numerical examples, the difficulty normally remains of distinguishing the behaviour of a load-bearing wing from a mere parachute, leading to misunderstandings that are difficult to resolve. The axial force propagated on the cables depends mainly on the wing’s flight speed squared and only in a linear direction from the surface of the wing. The flight speeds are in the order of 80m/s.

The forces generated amount to tens of tons of traction and have been specifically studied due to their relevance to the production of energy.



Duration, repeatability and reliability of flight

This appears to be another thorny issue, and is extremely debated in the numerous online communities where KiteGen is discussed. Here we can state emphatically that the flight is extremely safe and reliable. It should be borne in mind that the wind seen from the wing is always stabilized by the strategy of unwinding the cables, so that even a sudden and total absence of natural wind would not change the wing’s flight parameters as the system can retract the cables, thereby creating the necessary wind for the manoeuvres. Obviously, when there is prolonged absence of natural wind the wing has to be taken down in order not to unnecessarily consume the energy required to keep it in flight.


Take off and handling of the wing on the ground

The take off function has been brilliantly resolved by KiteGen, with an extremely reliable procedure that can also be interrupted or aborted after takeoff without causing damage to the wing or to the robot. Takeoff of the large power wing, which is rightly considered the most complex and risky manoeuvre, is one of the issues that have been successfully resolved, although in this case KiteGen has suspended the normal disclosure of its discoveries to the international scientific community. Its role as a first mover and prime innovator in the industry is not given the recognition and respect it duly merits. This has led us to resume the natural and customary privacy procedure regarding confidential information.

Tensile structural strength and durability of the wing

The wing chord length is currently 4 metres; by identifying the various sections and materials that compose the wing, it has been possible to validate its strength, providing a safety factor aligned along the entire kinematic chain, which includes the cable hooks, reinforcement patches, hinges on the flexible joint segments and wing sections.


Strength and durability of the UHMWPE cables

The ultra-high-molecular-weight polyethylene has been extensively tested in conditions of use, with measures taken to extend its service life. The results are in line with the theoretical predictions and indicate over a year of use before scheduled replacement.


Aerodynamic drag of the cables during flight

This point has undergone a recent theoretical evolution that has been very positive for the project, as the scientific literature has always simplified the aerodynamic model, combining the drag of the ropes and that of the wing to arrive at a particularly unfavourable overall parameter, which, however, was not validated in real tests. A complete and comprehensive mathematical model has allowed us to provide a usable theoretical validation and to document a further advantage of the KiteGen solutions, in that the use of the double cable provides a higher safety standard than a redundant system without any significant drawbacks.

Functions and load of the stem

KiteGen, having exposed the technology and opportunities to the public, is often subjected to baseless criticism, such as the misinterpretation of the function of the robot arms. These arms perform the function of supporting the wing on the ground, as it weighs about 300 kg, and are never involved in the operational forces of the system in flight, as the arms always remain collinear to the cables, imparting at most a normal force required for cable measurement and tension control operations, and thus in reality the arms are sensors.

Load on the first idler pulley

All the load of the cables is conveyed through the stem to the first pulley, which is positioned in a central position to the fifth wheel so that the loads from the cables do not place any stress on the structure due to variations in wind direction or flight altitude.

Angle of wrap and load on the pulley train

This is already a more enlightened and informed exception, raised by only a few of our interlocutors. This aspect is particularly developed in KiteGen and has led to the filing of two new patents for high-efficiency pulleys. The function of the pulleys fitted to the alternators is to transfer the flow and offload the tension of the cables, transforming it into motor torque.

Generating and rewinding power, duty cycle

As the wind speed varies, so does the productive duty cycle. Since the rewinding speed has been sized to 20m/s and the maximum unwinding speed in the production phase to 10m/s, it can be calculated that the duty or pumping cycle from one extreme is divided into one third of the time for rewinding and 2 thirds for traction. The power required for retrieving the wing in sideslip is 50 kW.

Efficiency of the conversion of the mechanical power into electricity

The mechanical power conveyed by the cables is converted by multipolar alternators with torque control and feedback on speed and combined position.

Flight control.

The control system is divided into a HAL (hardware abstraction layer) and a high-level procedure that decides the path of the wing through the airspace. The calculation methods are all based on quaternions, which are not susceptible to gimbal lock, eliminate singularities and possible ambiguities in the geometric interpretation of the signals and trace orientations up to ± 4π.

The high-level procedure was created with two simultaneous settings, the first is an analytical control provided with artificial intelligence and the second an intensive calculation approach with real-time physics and fluid dynamic engines, which implement a non-linear control based on multiple models, called predictive agents.



The previous activity has been carried out by and for KiteGen with the following results:

* The first HAWP (high altitude wind power) initiative worldwide to produce abundant electrical energy through this novel method, already in 2006, through a research prototype developed internally and then shared with Polytechnic of Turin as the experimental and study base for dozens of master’s and doctoral degree theses.

* The first initiative in the world to have completed the particularly efficient yoyo or pumping kite cycle with sideslip, selected after testing the alternatives and the implementation and cycle time.

* The first in the world to create an algorithmic control based on artificial intelligence and an inference engine demonstrating automatic piloting.

* The first worldwide to create a high computational intensity control based on parallel computing and physics/fluid dynamic engines in real time to implement and demonstrate non-linear and multi-predictive control.

* The first to demonstrate automatic piloting of the wing solely through the sensitivity of the ground-based stem to the direction of the cables, which has become a redundancy support in sensor fusion.

* The first worldwide to achieve totally instrumental take-off and landing without any human intervention.

* The first and only initiative to have collected and validated sufficient system specifications and to conclude the basic research stage in favour of industrialization on a utility scale.

* The first and only initiative to design, build and validate a large-scale, high-efficiency composite power wing suitable for energy production, in line with and derived from the high specialization in aerospace in the local region.

* The first and only initiative to have completed its final designs at a level sufficient to launch batch production of systems and wings of industrial quality and reliability.

* The sole intellectual property owner of the various HAWP concepts and the key technologies for their implementation.

* The sole owner of the KG-Carousel concept, which offers the GW scale generators.

Nevertheless, the following issues still need to be addressed: broadening of awareness and understanding of the technology, introduction of the technological learning curve and the tropicalization of the machines, and further scalability, both towards greater power levels and in terms of making the system more compact.  



With KiteGen we have documented certainty of finally having the most precious gift for mankind: an abundant, economical and sustainable source of energy.

The proposed technology has the capacity to fully meet the needs of the global electricity market, guaranteed by a natural “field” with a potential hundreds of times greater than human needs, with no adverse affect on weather patterns and global climate (ref. Ken Caldeira Stanford University). The low capital cost of the generator and the fact that the maintenance cost is proportional to the energy produced is a hopeful sign that the technology will have a beneficial dampening effect on energy prices for industrial needs in the short term and on retail electricity prices in the medium term. This would favour restoration of the industrial ecosystem and the creation of new businesses, which are currently held back by high energy costs and would benefit from the sustainability offered by this unprecedented source of abundant clean energy.

The low cost of energy would give access to markets other than that of electrical energy, such as transport and civil and industrial heating, now dominated by hydrocarbons, and the respective industrial sectors.

The type of innovation is mechatronics/aerospace and the most innovative element with respect to the state of the art is certainly the wing. The availability of an instrumented and implemented power wing is the principal enabling and exclusivity factor for large-scale generation of cheap energy from tropospheric wind. The concept of a wing of such great power is totally new. The laboratories around the world that have successfully reproduced the KiteGen tropospheric wind generator have shown an energy production and limit of a few dozen kW due to use of inadequate sport kites. KiteGen conducted an investigation on the wing at a very early stage, which seemed essential in order to reach utility scale, achieving a performance at least one hundred times that of small-scale systems, which produce expensive energy and find no path towards incremental scalability.

KiteGen therefore represents a leap in quality to give birth to the economic sector of tropospheric wind energy, made possible by megawatt class generators. Moreover, the modular design or, more simply, the kite wind farm concept, could even be scaled to the gigawatt class, i.e. to compete with the broader segment of the fossil fuel energy market.



KiteGen is well advanced in the research and experimentation of the High Altitude Wind Power (HAWP) concept. The innovations and results have continued at a considerable pace, with less attention paid to common perception and possible comprehension, albeit unintentionally, as this would have been an unsustainable cost and commitment. This has resulted in a widening of the cognitive gap and noticeable cognitive blocks, both in academic theoretical progress and in many scientific publications on the emerging science of KiteGen.

One goal of the project is to create and broaden understanding of the project scenario in order to establish or recompose a critical mass of players that can creatively guide the industrial initiative and the strategic relationships required for its foreseeable status as a large industry. There is therefore an essential need for effective training support, which should be provided by the institutions in the region. The stakes are high, the energy market is virtually untapped, abundant and very receptive, and the current objective is also one of organization, as the project can now pass from the hands of the scientists, designers and prototype builders to those of the technicians who optimize production, including production line equipment. From this perspective, collaboration with industrial partners, like that with our composite manufacturer, is of strategic importance in order to address the issue in the area of know-how with the very high quality standards required.

In order to justify the path taken by the project, which was arbitrary only in appearance, we can affirm that we have discovered and documented that it is subject to thresholds of scalability, which reside mainly in the design sizing of the power-to-weight ratio of the wing:

•             Up to 80kW nominal power, implementation of the technology is simple and many laboratories have successfully reproduced and confirmed experiences very similar to Mobilegen, our first 40 kW KiteGen generator, which only required a few weeks of work for its construction and functional operation, using wings designed for sports purposes. All possible evolutions have already been explored at this power level, including the production cycle and automatic flight with multi-predictive control software.


•             In the 80kW - 3MW range we have tried various solutions: if the wing is large and made from cloth (dacron sail fabric), it gives way under stress and/or performs inadequately; if it is rigid and made from composite material, it is too fast and control intensive and requires more wind for takeoff, as well as a generator robot with a long enough arm to provide sufficient space for the necessary manoeuvres.


• Finally, a sizing of 3MW (or above) has enabled us to show that a large composite wing of 130 m2 begins to support itself when flying at 14m/s and with 2 m/s of natural wind, which is already quite manageable in terms of the take-off. However, the manoeuvring robot permits no approximations, as we are talking in safety terms of a sizing of over 40 tons of cable pull and a double arm to support the wing at rest in an unfolded configuration.

The general design rule that the tests of the various KiteGen prototypes have highlighted is that as the wing becomes larger and more efficient, and simpler in technological and operational terms, the ground robot becomes decidedly much more demanding, with much greater performance requirements. Obviously, the robot is simply a special machine that has to respond to clear specifications, and therefore only requires sound engineering practices, without involving design uncertainties. The solution to the problem of scalability, which necessarily must tend towards very large versions, both in terms of size and of power, was based on physical/aerodynamic issues rather than strategic choice. This step has been similarly encountered and confirmed by all the laboratories around the world that have replicated the KiteGen experiences with similar success.

As might be expected, the KiteGen project is beginning to become known and recognized by stakeholders. We are also the only Cleantech “100 to watch” company from Italy and the only one in the world dealing with renewable energy. Nevertheless, we often encounter criticisms in the social media, some very agitated and others accusing us of an attitude that can be described as “megalomania”.  This is certainly an opportunity to explain that the main reasons for the disproportionate sizes are the global energy problem and the undeniable magnitude of the untapped field that KiteGen seeks to exploit. KiteGen is merely a light, enabling technology that allows effective utilization of this field.

In a similar way to KiteGen, the phenomenon of “horizontal drilling”, which has revolutionized the hydrocarbon sector, was not understood immediately. The mere invention of a technological support cannot be accused of being disproportionate, although the results are known and highly relevant.

Put another way, the invention of the fishing rod bears no responsibility for the large amount of fish in the sea, but fishing rods can feed an entire population.

Consequently, it can be clearly understood that if we are speaking of exaggeration, this does not apply to KiteGen. However, the evident incapacity of the institutions to relate appropriately with KiteGen in order to verify the programme’s undoubted strategic importance, which KiteGen has highlighted and is offering to the country, is unjustified. Yet important events in the energy sector always involve the direct participation of the institutions and governments of the world.


The R&D work carried out by the proponent, also as part of the co-financed regional project “Wings & Power”, has led to an advanced stage of development and the achievement of TRL7, as recognized by ENEA (the Italian National Agency for New Technologies, Energy and Sustainable Economic Development) in the parliamentary audition dedicated to tropospheric wind technologies held on 08.01.2015 http://www.infoparlamento.eu/index.php?option=com_mtree&task=att_download&link_id=5774&cf_id=76.

Having achieved this goal, our activities have been focused on the industrialization of the technology through validation of the components and their specifications, in view of bringing most of them up to TRL 8. This proposal is therefore motivated by the need to accelerate the start of production and reduce the time to market. The public support required, far from significantly covering the costs of industrialization, which amount to €80 million, is mainly geared towards recognition and acceptance of the previous R&D work and the future industrial development, with its corollary of employment and attraction of new investments. This recognition is in itself an engine of trust and cooperation on the part of the numerous companies in the region which will be involved as suppliers.



Sequoia Automation, the proponent’s operational partner company, was created specifically (from the sales of a business unit in 2006) as an engineering research and study centre devoted entirely to the KiteGen project. Therefore the finalization of the project, with achievement of the industrialization of the product, is its prime and founding objective. The R&D activity has been part of a well-defined strategic plan, as is the validation and industrialization activity currently in progress. The public intervention received in support (the aforementioned “Wings & Power”) would also have permitted a corporate reorganization, necessary for shifting the focus of the personnel and facility from the R&D phase to that of industrialization, had it not been reduced from the original €7 million to less than €3 million, resulting in increased difficulty in recruiting, training and retaining the necessary highly skilled personnel. This reorganization is therefore still pending and increasingly urgent and necessary to avoid having to sell the technology as a whole, presumably to major foreign players.



Energy production from renewable sources has two available global markets. The first, which is worth US$500 billion a year in terms of investment based on COP21 and the Kyoto Protocol, includes a share for innovation and massive support for serial deployment of mature sources, mainly wind and solar power. The second is the far more important energy market, which includes fossil fuels. In the short and very short terms, if properly informed regarding the potential of KiteGen, the first market could divert significant proportions of its funding for the support of this innovation and the deployment of KiteGen. It is sufficient to mention the Breakthrough Energy Coalition established by Bill Gates, which aims to invest $2 billion in innovation and has already publicly mentioned KiteGen and the HAWP sector as projects worthy of attention.

After the project for the first industrial production batch, the partner companies will have acquired the expertise and capability to produce the most important parts of the system: the wing, sensors, light electronics and software. They will also have acquired the capacity to manage the logistical and technical coordination of a supply chain for all the other components, including mechanical and electromechanical parts, power electronics and cooling systems. This capacity will enable the subsequent production and installation of batches of generators in the order of hundreds of units per year. Putting the generators into production will require the establishment of companies dedicated to the maintenance, supervision and operation of the plants.

The competitive advantage acquired thanks to the intellectual property rights and industrial research will allow the implementation of a strategic plan for the expansion of the production capacity in the order of thousands of units per year. The direct employment of resources in Piedmont (including partner companies and linked activities) to enable the launch and operability of the initiative can be estimated initially at around 30 researchers for R&D activities, 10 administrative operators for human resources, administration and procurement activities, 10 sales managers for global wind farming start-up activities and 120 other workers including production operatives, maintenance technicians and product engineers for the manufacture of the KiteGen generators in the factory. The total initial employment will be at least 170 people at one year from the start of the initiative. By the second year, another 100 workers will be needed for the construction and the maintenance of the KiteGen generator fleet. Subsequent expansion of production to batches of thousands will result in an increase in employment to over 2,000 workers.



The project, if implemented, will guarantee an extremely high return of employment, plausibly in the order of hundreds of thousands of workers. This is because once the competitiveness of the energy produced with this technology has been verified, the market will expand in a predictable and calculable manner, justifying the promise. This return of employment may also be seen in the creation of an industrial chain ranging from the manufacture of the machines, wings and cables to the installation and management of tropospheric wind farms (wind farms), which can also lead to redevelopment of the areas most degraded in environmental terms and the possibility for local authorities to become energy autonomous and/or energy producers.

These more than reasonable certainties are based on:

1) An energy field of unimagined magnitude (the tropospheric wind harvestable from Italy amounts to at least 100 times the exports in equivalent energy by Saudi Arabia)

2) The ERoEI of KiteGen technology, which is 5 times that of the best crude oil during the economic boom of the 1950s (30 times that of traditional wind power, 90 times that of photovoltaic energy and 270 times that of CSP)

3) An incontrovertible theoretical basis: Google Scholar displays over 350 results on KiteGen

4) Great experience and architectural and technological clarity acquired by the proponent

5) Extensive indicative experimentation necessary for a breakthrough technology, which has also provided the “proof of concept” of the energy production cycle

6) Non-intermittent nature of the source.



Downstream of the project for the first industrial production batch, it will be necessary to expand the supply chain and linked activities, as the electricity sector worldwide requests the installation of 2 million KiteGen generators in 20 years. This results in an increase in the production capacity in the order of 10,000 times that implemented for the first batch. The light logistics and high added value of the mechatronic parts of the product eliminates the need for exasperated optimization of the production costs through outsourcing and leads to a hundred-fold increase in value, to the benefit of the host region, attracting investments in the order of tens of billions of euros.  Electricity production and showroom initiatives, such as the kite farm/campus in Giaveno, and an adequate expansion of current technological and public and private research centres will be required to provide the personnel training and R&D necessary to keep the product updated and competitive.



KiteGen is the worldwide owner of the best tropospheric wind energy technologies

The impact of tropospheric wind energy is disruptive because the electricity produced at the projected cost enters directly into competition with thermal sources and transport fuels. With an electricity cost of less than €15/MWh, synthetic diesels produced by capture of atmospheric CO2 and extraction of hydrogen from water become competitive with that obtained from fossil sources, thereby accessing a TAM (Total Available market) of $8,000 billion/year, i.e. the entire current energy market. It follows that the innovative effects of the proposal will also impact sectors other than electricity generation and radically affect their processes; for example, boosting heating/air conditioning in both summer and winter via high efficiency heat pumps (already cost-effective compared to retail electricity costs at below €90/MWh), electric cooking (e.g. induction cooking), the recovery of transport battery materials, jet fuel, electro-foundries, metal smelting, metal forming, silicon refining, desalination, fertilizers, etc., decisively stimulating the various related industries.




For the sake of brevity, assertive evaluations will follow. They can be documented and debated with due accuracy. KiteGen is always open to exchanges at the best competence tier of the sector. In fact, KiteGen worst hindrance is indeed the lack of forethoughts while establishing energy policies.


Generic innovations in energy


KiteGen concept arose in 1999 after an analytic research on possible future energy sources, lead by CESI (now RSE) and GRTN (now Terna), with a key contribution from professor Luigi Paris (father of Italian electric energy). The strict method used allows us, even as of today, to affirm with proof that KiteGen has a Q factor from 30 to 1000 times greater than the most notorious actors in this field, and is the one and only able to lead the transition from fossil fuels.

Following examples confirm what we just stated.

Sea power

Pelamis, WaveDragon, Oyster Acquamarine, Scotrenewables Tidal Power, Pewec di ENEA, OTEC

Wind power

Beatrice, AlfaVentus, London Array, El Hierro, Sandia 20MW HWT

Solar energy

Ouarzazate, Andasol, Topaz Solar Farm, IBM Sunflower, Ivanpha, Archimede

Nuclear and coal

ITER, CCS, IV generation reactors


HAWP competitors

KiteGen has been the pioneer of high altitude wind power, and kept on pushing to increase its theoretical and practical advantage over supposed competitors, having industrial-scale production as declared objective. As owner of international patents, KiteGen is also free to operate, while having the right to require overlapping operations (or right out counterfeiters) to cease operations. KiteGen concept is generally seen as the best in terms of feasibility and potential over present international competitors (Makani, Altaeros, Wind Lift, Skysail, SkyWind Power, Magenn, E-Kite, KPS, Ampix, Twind).



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The steps of KiteGen project through prototype testing and decision-making process


The three main operative and performing benefits of KiteGen system are:

1) The machine is about 100 times lighter than a corresponding wind turbine. This will have a significant effect on plant CAPEX and will greatly simplify installation logistics (transport, groundwork, infrastructures, ...).

2) The wing catches at least 40 hectares of wind front, while a corresponding wind turbine catches only 1 hectare. This allows KiteGen be less perturbing of wind flux, which is basically left undisturbed. Therefore, KiteGen can exploit the aerodynamic advantage of natural wind speed unlike the optimized interaction of a classic wind turbine (Betz's law). This means KiteGen is 4 times more productive, active aerodynamic surface area and wind speed being equal.

3) Wind is much faster at high altitude. Wind at an altitude of 1000 metres blows usually twice as strong compared to traditional wind turbines operating heights. This translates in a further increase of productivity by 8 times.

We are facing a theoretical performance improvement (or cost reduction) compound factor of 3200 times compared to wind turbines, being aerodynamic conditions equal.

Life-cycle analyses confirm these figures. In our practical industrial design, this huge performance increase is exploited not to reach high power peaks instead to increase energy availability through the year, avoiding significant power fluctuations. In this way, generator production gets near to a baseload-type performance, almost solving intermittency issues.

This production target obviously implies a mature system, nurtured by substantial investments aimed at technology development. The improvement we can nowadays esteem for our prototypes is 16-fold. Definitely remarkable, yet dragged down by some limiting factors like machinery heat balance, issue not yet tackled and completely solved. 

These are the promises of high altitude wind power, and they have already been proved true. But we need to overcome a hurdle to make them happen, that is joining with the natural technology-learning process without relying on an incentive system, let alone public funding. This means that in order for the machines to have a future they must be competitive against fossil energy sources, also in terms of energy costs, from the very beginning.
This among other reasons is why we decided to design wings and machines fitting the job, with a nominal power of 3 MW, thus forsaking the development of the smaller 40kW ones.
If only we could have hoped for a slight support for a few years, even the first experimental machines could have generated sufficient revenues to keep up development and industrial processes; we were unfortunately denied this as our peculiar approach rendered us atypical players in renewable energies.


Reference description of depicted key phases:

ref. 1) A technological idea has no value until validated by a solid theoretical evaluation. Intuitive physics alone doesn't cut it, on the contrary calculations and high-detail simulations are needed to outline the architectural hypotheses and guide next design phases.
For KiteGen this had been a recursive task, which was considered accomplished when evaluation of architectural options and their respective performance became solid and clear.    
ref. 2) The first test that confirmed a critical section of theoretical validation: the possibility to operate a flying wing with a servo-assisted system. The test was devised to validate a modular subset of Carousel, namely the kite unit. Positive results during this phase surely allowed the project to advance forward in its path.

ref. 3) Technical successes and research are not backed up by public and private stakeholders, Carousel has been generally criticised for its big size, disregarding the fact it could generate as much power as a nuclear plant at a fraction of the cost. 
After the "wing-slip" intuition, the generator design with the single kite driving unit was introduced, producing energy with a yo-yo cycle. Every step of the cycle got validated during 2008, allowing a thorough exploration of possible limits and faults to overcome during next phases.


ref. 4) Industrial property is paramount to change a product idea into something marketable during negotiations. We have been granted our first patent in 2009, followed by many others, establishing our worldwide priority on high altitude wind exploitation. 

ref. 5) KiteGen's technical success pushed many laboratories worldwide to reproduce and repeat our experience of high altitude energy generation based on wings.
Many of them managed to obtain similar results, confirming KiteGen operations: Delft University, Festo, WindLift, Skysail, Makani Power, Swisskitepower, etc.
On Ted, Damon Vander from Makani shows their test to verify our approach, while making up a pretty weak reason to avoid admitting that it is our industrial property.

ref. 6) KiteGen's initial concept did not consider the stronger and steadier wind at high altitude while evaluating its competitive benefits. Our evaluation was only based on the huge weight reduction and much wider intercepted wind front.
The first article describing wind speed increase, besides the notorious effect described by Hellsman's exponent used for wind turbines, was published in 2007, followed by a work from CESI (now RSE), and finally the publication of Ken Caldeira e Cristina Archer.
These works also established the independency of wind abundance from specific areas, basically stating that any two locations might give roughly the same production results. That was a pretty interesting piece of information, in the light of which we identified a number of possible sites on which restriction on flying conditions are already in effect.
In the meanwhile we also dealt with administrative tasks to obtain authorisations, which we got, even if this activity was not crucial as our machine's logistics are pretty agile.

ref. 7) Inertial sensors and position sensors are fundamental to allow automatic flight. They can be installed on the wing, but they are also useful on the ground, especially on the "Stem" (Science Technology Electronics & Mechanics), which is the generator's mechanical arm, used as a flight-direction and rope-traction sensor. Wing position can be easily calculated combining vector information with rope's length. This allowed us to successfully test various automatic flight session of arbitrary length. This milestone has been brightly passed and documented, but the opposite wouldn't have stopped the project as manual control would still be profitable and appreciated, and it has already been required by some international partners.

ref. 8) From this point on, every theoretical and practical test on the generator and the research prototypes got positive results, thus the project went into its industrialization phase with the decision to scale the project to a 3 MW machine. This was done in a commercial perspective to achieve competitiveness for energy feeding into the grid.

ref. 9) The "Stem" performed extremely well as a sensor, yet the project requires inertial sensors on board of the wing to overcome possible ambiguities and improve data accuracy and completeness. In this phase we tackled the on-board electricity supply issue and radio communication of data gathered during flight.

ref. 10) We recently improved wing design both theoretically and physically. It is an object of utter resilience and lightness, with a semi-rigid behaviour well suiting the generator's yo-yo flight cycle. After our inquiries at various international possible suppliers and partners did not receive satisfactory answers because of the unprecedented and unique specifics required, KiteGen chose to manufacture this core component in-house.

ref. 11) Take-off methods. Soon we will be able to illustrate the details of this activity. We identified seven possible take-off procedures, most of which have already been tested.

ref. 12) Machinery and components must be manufactured in batches to ensure high productive and manufacturing quality standards. This requires organisational and financial investments on supplies. We agree with the many who say that to invent seems easier than begin production.

ref. 13) High altitude wind power has the potential and all it takes to be considered the power source that will replace fossil fuels. We would appreciate if the institutions helped us bear the responsibility of a development, which could turn out to be, and will likely be, the solution to the perfect storm (economy, resources, environment) raging on us.
Surveys and diligences could establish how likely it will be so, and considered how high are the stakes, even a medium/low rating of success chance would account for institutional support, not only financial, but spanning from training to proposal of industrial sites to convert and employ for the new energy device. It's clear that in our eyes delays are troubling, for working and producing limits, but the success of the concept itself is certain and beyond every reasonable doubt. The burdensome diligence we daily spend on technological issues perhaps made us neglect public relationships and communication, but with KiteGen Venture we are at a turning point.