How much does the wind blow in your future offshore wind project?

There is absolute consensus within the wind industry, that wind resource is a key input parameter for the initial evaluation of any seabed area for the potential development of an offshore wind project – there is no doubt of its importance, in fact, if we look at the physics behind what matters to extract Power from wind speed, we know that averaged wind resource on site counts to the power of 3! 

In other words, having a site with 1 m/s more in average wind speed could lead to turbines extracting double the amount of power. Therefore, it is crucial to have wind resource data under control for any offshore wind project development.

 Wind Power Output versus Wins Speed (ResearchGate)

The range of data quality, hence the uncertainty, varies tremendously depending on the stage of your project. You can find low resolution wind data sources and upgrade them to well postprocessed acquired measurements, depending on the phase of your project when you are performing bankability yield assessments. 

In this article we, will dive into the project origination phases and therefore we want to describe the most popular wind resource data available. 

ERA5 Link to Copernicus 

ERA5 dataset from the European Centre for Medium-Range Weather Forecasts (ECMWF). The data is acquired from global satellites and ground-based, airborne, and seaborne measurement systems, together with a very strict quality assessment to ensure high availability and coherence. The industry uses most commonly the “100 m u/v-component of wind” channel, which provides you with wind speed time series with 1h timestamps for more than 30 years for a specific location. You should be aware that this database covers the entire world, but with a resolution of 32 km, which means you have data available in one location and then the closest next data point is 32 km further on, in the 4 main directions. Using the statistical values of this data source is a good start, but its low resolution makes it challenging to trust for a specific project site. Imagine you are checking a future site close to shore, and the wind speed data you are checking from the closest ERA5 location is actually on land! Not representative at all! In this case, you would need a service provider such as Vortex that can provide datasets downscaled to the location of interest.

MERRA-2 

This dataset could be described as the cousin of ERA5, but developed and maintained by GMAO, (Global Modelling and Assimilation Office), who makes wide usage of NASA's satellite observations. In this case though, the grid resolution of the data points is lower than the ERA5 one, being approximately 50km.  

Global Wind Atlas 

DTU Wind Energy, in Denmark, with support from the World Bank and Vortex for the current version, took the ERA5 datasets to a new level, increasing the resolution from 32 km to 3 km with a reanalysis and mesoscale method!  DTU then also introduced a local wind climate for every 250 m at five heights, so on a 250 m grid, there is a local wind climate estimate for every node.  

This new paradigm in available wind resource datasets is based on 10 years of mesoscale time-series model simulation from the latest ERA5 data from 2008-2017. 

Global Wind Atlas

New European Wind Atlas 

The New European Wind Atlas provides a mesoscale model that covers the entire EU plus Turkey and 100 km offshore, as well as the complete North and Baltic Seas. The grid is at a 3km resolution and covers 30 years of ERA5 data, or from 1989-2018. The methodology of the microscale modelling to end up at a 3km resolution is similar to that of the Global Wind Atlas, except a finer grid of 50m spacing is used. For the datasets provided, there is also data available for local temperature and air density.

The New European Wind Atlas (NEWA) is an ERANET+ project, that is funded by the European Commission.

With NEWA, it is also possible to download time series for a given location.  

European Offshore Wind Atlas (ResearchGate)

Vortex Map 

Despite having played a crucial role in developing the latest versions of the Global Wind Atlas, Vortex has also developed a more accurate map as an entry door to all their commercial premium wind resource datasets.

This map is available for Vortex as well as Youwind users and provides statistical wind resource data at the best possible resolution, spanning 20 years of ERA5 data: 1 km! 

Youwind recommends using the Vortex map and products when doing the initial screening and layout design, as the maps have been calibrated for any given location with local measurements. The product, therefore, is the one that shows the least uncertainty with mesoscale models, which is why Youwind uses the Vortex map in the platform. The Youwind and Vortex platforms are also integrated with an API so that users of premium datasets such as FARM, SERIES, LES, or others can use them directly in Youwind to provide an accurate and the lowest uncertainty dataset for analysis purposes.  

 Vortex  map integrated into Youwind platform (Youwind)

Are these the only free sources to proceed with the first wind resource checks?

Definitely not, as many countries, such as Australia, the US, Norway, the Netherlands, or France, have developed their own national wind atlases. However, this article provides you with some clarity about which are the most popular and freely available wind resource data sources, you can start checking out if you are entering this industry, and therefore the ones that have the fastest acceptance when global teams work together in the offshore wind industry.