feature article & competition

The Ventos Story

Sites with complex topography and forest can be a major problem for developers, wind farm operators and manufacturers alike.

Always on the lookout for better ways to serve our clients, Natural Power has a joint venture agreement with CEsA, Centre for Wind Energy and Atmospheric Flow, based in the Faculty of Engineering of Porto University. This has brought into our toolkit the suite of tools known as VENTOS (Portuguese for wind).

VENTOS belongs to the family of computational fluid dynamics (or CFD) solvers. Put simply, CFD models solve fluid flow over complex geometries by breaking the flow domain into manageable chunks, or volumes, where each volume is related to its neighbours. The best CFD models will, however, always be complex to operate - requiring expert engineers to ensure optimum results.

So what makes VENTOS different? We believe it is easily the best CFD code due to its provenance as the most rigorously validated, designed for wind energy model with the least simplifications - indeed it needs a substantial computer cluster to run efficiently.

To ensure the best results from VENTOS, all our operators have university degrees in CFD modelling and take Ventos specific training at CEsA.

Ventos began life in 1995, as part of a PhD thesis by Fernando Aristides Castro, supervised by Professor José Laginha Palma. It was, and continues to be, a research platform for CEsA.

Over the years, an enormous amount of validation effort has put by CEsA - a difficult and time-consuming task which is the gateway to acceptance by the scientific and engineering community. This gave rise to several additional PhD theses and papers in peer-reviewed journals, underlining the seriousness of the work which has gone into developing this code and the theory behind it. A full list of academic references can be found on our website: www.naturalpower.com/VENTOS

"VENTOS allows us to identify siting issues before they become a liability rather than afterwards" noted the Director of Ostwind, a company who are specialised in developing successful projects and implementing high yield wind farms in France. "With Natural Power we have the assurance that the CFD code is being used in the correct conditions".

Further development has concentrated on adapting the model to cope with a forest canopy - technically a very difficult problem. This resulted in one of the first effective canopy models, and the best validated, to be used in the wind industry.

CEsA's belief is that effective use of CFD is only possible when combined with experienced use and scientific rigour. This defines our approach and methodology; aware of the model's strengths and weaknesses, our clients are assured of getting the best that the technology can offer. Within Natural Power this experience was brought in-house with the acquisition in 2007, of Ventec, a consultancy based in Strasbourg.

VENTOS is now routinely used by Natural Power to solve complex problems for our clients. These range from informed micrositing to energy prediction and asset management - for example exploring reasons for underperformance by better understanding wind flow across the site.

VENTOS, true to its role as a research platform, is very much alive and further exciting developments are ongoing. Natural Power stays closely involved with the group, and is delighted to have the benefits of working with such an experienced team.

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Competition Time!

This month's competition is a simple ‘guess the object’. The object below has some relationship to the wind industry but can you guess what it actually is or might be used for? There will be two prizes available - quickest correct entry, and most humorous / original entry.

Simply email your answers to sayhello@naturalpower.com including your contact details:

And this edition's prize is an eco-friendly wind up radio (courtesy of www.naturalcollection.com):

Entries must be received by 20th February 2007 and winners will be announced in the next edition of natural news, along with full details of the origination of the image. This competition is not available to any Natural Power employees, or their families.

Good luck!

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