Ion Paraschivoiu’s book on Wind Turbine Design with emphasis on the Darrieus concept is the standard work on Darrieus wind turbines. I have it on my bookshelf, refer to it often and ordered it for our university library where students can access it.
— Brian Kirke,Adjunct Senior Research Fellow University of South Australia, Australia Division of Information Technology, Engineering and the Environment
In the recent 10 years in China, many companies and people saw the potential of the VAWT in wind industry. After we meet and talked with Professor Ion Paraschivoiu in Canada, all the problems were gone. Nothing is impossible! Professor Ion Paraschivoiu use his professional knowledge and 30 years of experiences in VAWT to make true our dream. Now ENGGA is building the world largest and highest 2x2 MW VAWT turbine based on Professor Ion Paraschivoiu’s suggestions and IOPARA’s professional consulting reports. Now the next step for ENGGA is to design the 2x6 MW VAWT, also cooperating with Professor Ion Paraschivoiu and IOPARA. Professor Ion revealed the nature of VAWT with is DMSV model, and also showed us the potential of VAWT.

If you are have dreams on VAWT, or you have problems on VAWT, please contact with Professor Ion Paraschivoiu and IOPARA immediately.
— Creo Sun, Project Engineer Guangzhou ENGGA Generators Co. Ltd, China
Professor Paraschivoiu stayed at Tottori University in Japan from October, 2004 to May, 2005 during his study leave. In his stay, we had precious time by taking his lectures and conducting a joint research with him about small VAWTs. Triggered by this joint research, I had the honor of being one of the translators to the Japanese version of his book “Wind Turbine Design”. This book has been very useful for Japanese researchers, engineers, and students, as the first full-dress review book of VAWTs. I hope Professor Paraschivoiu’s health and his further successful evolution in study and business.
— Yutaka Hara, Associate Professor Applied Mathematics and Physics Course Dept. of Mechanical and Aerospace Engineering Graduate School of Engineering, Tottori University
Many aerodynamic consulting companies have the competence to design blades for traditional wind turbines; however, we found only one company that has the mindset, staff and proficiency required to design the blades for Vinci-Tech innovating wind turbine, that company is IOPARA.
— Stefano Mangano, President & Founder of Vinci-Tech Inc. Vinci-Tech Inc., USA
Our project involved the development of an upgraded VAWT that was operating in very unique wind conditions and using non-conventional rotor designs. The IOPARA software and libraries were customized to give us an excellent overview of the rotor performance and important design criteria. The simulations provided were pivotal in understanding how to achieve optimum performance. In our opinion, this level of process simulation and team open-mindedness is an essential tool in designing solutions for applications in the field of fluid dynamics.
— Frederick Churchill, P. Eng., President & Founder of OrganoWorld OrganoWorld, Canada
We only have positive experience with our work with IOPARA, fast accurate and a very good dialogue during the entire process.
— Kent Thoresen, Technical director & Founder of Norwegian Ocean Power AS, Norwegian Ocean Power AS, Norway
One of our wind turbine clients tasked Engenuity with the development of the aerodynamic and structural design of two different classes of VAWT’s prior to Certification testing. It was recognised at a very early stage that the success of the projects would be largely determined by the accuracy of the aerodynamic models, since aerodynamics is the key to VAWT performance. After a search it became evident that only one company had the track record in VAWT performance prediction that we required. We enlisted the services of IOPARA Inc to generate the aerodynamic characteristics of both turbines using the CARDAAV Code. The predictions were instrumental in helping us reconstruct the aerodynamic performance maps in areas which we were not able to derive from wind tunnel or field testing. Following the initial work we have gone further with IOPARA Inc and this has enabled us to validate our own turbine code, the WTETM (Wind Turbine Emulator) which uses CARDAAV derived, or field test derived, aerodynamic performance maps to predict the transient response of turbines when subjected to any wind gust. The WTETM is focused on the most important aspects of any wind turbine - Safety and Energy Yield through the optimisation of the Turbine Control System. The predicted response is then fed back in to our structural dynamic codes to provide evidence for structural integrity requirements.

We would like to thank Ion and his Team for their very useful advice provided during the course of the projects and the professional service which we received from IOPARA Inc. throughout the course of the works.
— Owen Kenning, Lead CFD Analyst Engenuity Ltd, UK
The book ‘Wind Turbine design’ is a great reference for those wanting to better understand the aerodynamics driving the design and performance of vertical axis wind turbines. It proved to be a useful resource throughout the design process for a client’s unique wind energy project.
— John Winkler, Ph.D., Chief Aerodynamicist Swift Engineering Inc., USA
In the past, we studied several papers of Prof. Paraschivoiu’s about vertical axis wind turbines and their simulation models. Now, it is wonderful to find most of those subjects included in the Prof. Paraschivoiu’s book “Wind Turbine Design”. The book covers the most important issues about wind turbines and a very detailed treatment of dynamic stall phenomena. The book is very pleasant to read and it is a veritable mine of numerical and experimental data, useful for research and professional work. So, it is a very pleasure that Prof. Paraschivoiu is now cooperating with Politecnico di Bari, Italy, during his sabbatical leave.
— Bernardo Fortunato, Full Professor, Sergio Camporeale, Associate Professor, Marco Torresi, Researcher Department of Mechanical and Industrial Engineering Polytechnic University of Bari via Orabona 4, Italy
Professor Paraschivoiu book, ‘Wind Turbine Design: With Emphasis on Darrieus Concept’ has allowed me and my companies to use his expertise in the development of the Windspire 1kW system and the larger 1MW SweptWind both vertical axis wind turbines. His theories and practical explanation of the technology used in VAWT design far exceeds that which has been implemented in the market to date.
— Mike Hess, Co-Founder of Windspire Energy Inc. (formely known as Mariah Power Inc.) Windspire Energy Inc., USA
I am writing to express my gratitude for your excellent design services and technical support you provided in development of Mariah Power’s wind turbines.

We found you through purchasing your book, “Wind Turbine Design”, which well-explained the concepts of vertical axis wind turbine technology. Subsequent hiring of IOPARA was instrumental in our development of first through follow on sized wind turbines, called the Windspire. The modelling results provided were very detailed and they always closely matched our later field test results.

I would strongly recommend any companies working on vertical axis wind turbine design to consider contracting IOPARA to improve their turbines.
— Chris Gabrys, Ph.D. Chief Technology Officer Mariah Power Inc., USA
Wind Turbine Design With Emphasis on Darrieus Concept has become the standard reference for researchers seeking to build on past work and further the development of vertical axis wind turbine (VAWT) concepts. Ion was a key collaborator with the VAWT team at Sandia National Laboratories in the heyday of VAWT research in the 80’s and 90’s and has managed to capture that history exceptionally well in this book. Those who launch into this area without a thorough understanding of what Ion clearly presents in his book do so at their own peril.
— Paul Veers Chief Engineer for NREL's National Wind Technology Center Past Distinguished Member of the Technical Staff at Sandia National Laboratories Editor of the journal "Wind Energy"
Dr. Ion Paraschivoiu’s ‘Wind Turbine Design’ text is very comprehensive and useful in VAWT design.
Iopara, with their CARDAAV and CFD, 2D aerodynamic VAWT analysis computer programs have provided valuable parametric design evaluations of our VAWT systems. They are a valuable technical resource.
— Robert N. Thomas, CEO of Wind Harvest International (WHI) Wind Harvest International Inc., USA
I started working with Ion shortly after I started working with the Sandia National Laboratories Wind Energy Group in 1980 on the analysis and design of Vertical-Axis Wind Turbines (VAWTs). We at Sandia adopted his CARDAA code and we continued to use variations of that code as one of our primary design tools for the next 15 years (for both aerodynamic performance predictions and to provide aerodynamic loads information for our structural analysis codes), until we quit working on VAWTs in 1995. During those years we worked closely with Ion on a number of VAWT-related projects and I developed a great deal of respect for Ion and his work. I continue to receive inquiries about VAWTs and codes for predicting their performance, and I always suggest that Ion’s “Wind Turbine Design...” is an excellent resource for learning some of the history of VAWT development and for gaining an understanding of the various analysis codes. Anytime I receive an inquiry about finding someone to provide consulting work on VAWT technology, I recommend Ion and his consulting group. In my opinion, Ion is one of the world’s leading experts on VAWT technology.
— Dale E. Berg, Ph.D. Retired from Sandia National Laboratories in December, 2011 after working in the field of wind energy for 32 years
Thanks to their advantages (no need for a wind orientation mechanism, low sensitivity to turbulence, low noise, ease of installation and maintenance, reduced manufacturing costs, etc.), vertical axis wind turbines have known a growing interest. For many years, Professor Ion Paraschivoiu has been involved with the optimization of Darrieus-type vertical axis wind turbines and in the development, design and promotion of vertical axis wind turbines. 

In this field, Professor Ion Paraschivoiu’s book “Wind Turbine Design - with Emphasis on Darrieus Concept” represents an important contribution. Featuring the fundamentals of vertical axis rotor calculations and basic criteria for the design and operation of vertical axis wind turbines, this book is a masterpiece for scientists and engineers worldwide. The translation of this book in Japanese and Chinese demonstrates the growing interest of specialists for these turbines. 

Our collaboration with Prof. Ion Paraschivoiu has last for over 10 years. With some uncertainties in vertical axis turbines, we have greatly benefited from valuable consultations on rotor optimization from Professor Ion Paraschivoiu. I also participated in the development of research projects on wind energy conversion systems and micro hydrokinetic turbine. Currently Professor Ion Paraschivoiu is on Sabbatical leave at the Technical University of Moldova.
— Valeriu Dulgheru, Ph.D., Dr.Sc.Prof. Head of Department Theory of Mechanisms and Parts of Machines Technical University of Moldova, Republic of Moldova