| Experiences and results from a wind resource exploring campaign 2003- in west
Greenland.
Like many other countries, Greenland is trying to reduce its dependency of fossil fuel by
implementing renewable energy. The main challenge is that the people live on the coast in
scattered settlements, without power infrastructure. Based on this a wind power
potential project was established in 2002, funded by the Greenlandic government and
the Technical University of Denmark. We present results and experiences of the
campaign.
1 Field campaign
There were only a few climate stations in or close to settlements and due to their positioning
and instrumentation, they were not usable for wind resource estimation. To establish met
stations in Arctic areas with complex topography, there are some challenges to face; mast
positioning in complex terrain, severe weather conditions, instrumentation, data handling,
installation and maintenance budget.
The terrain in the ice free and populated part, mainly consists of mountains of different
heights and shapes, separated by deep fjords going from the ice cap to the sea. With a
generally low wind resource the focus was on the most exposed positions close to the
settlements. Data from the nearest existing climate stations was studied for background
estimations of predominant wind directions and extreme wind speeds, and based on that the
first 10m masts were erected in 2003.
2 Instruments
The first installations used standard NRG systems with low cost NRG instruments. For most
of the sites this low cost setup did a good job, but there were some problems with the first
design, including instrument and boom strains. In subsequent years, the systems were
updated several times to be able to operate in the extreme conditions. Different types of
instruments, data logger and boom systems were tested to get better data quality and
reliability. Today 11 stations with heights ranging from 10-50m are installed and equipped
according to the IEC standard.
During the first years, the influence of instrument icing was not considered, but recently
one of the sites was equipped with an ice rate sensor and a heated ultrasonic anemometer to
study the ice influence.
3 Results
The predominant wind direction for most sites is away from the ice cap at the center of the
continent, but for some coastal sites it is north or south. The north-south wind pattern is
expected from the synoptic patterns and the barrier effect of the ice cap. The sites
where the predominant wind direction is away from the inland ice are dominated
by katabatic wind systems from the ice cap and form valley systems. These sites
also seem to have the highest wind resource and will be studied further. A good
example of the influence of katabatic and thermal wind systems can be seen in the
measurement data from Sarfannguit and Nanortalik 66 and 60 degrees northern latitude
respectively.
In future work, these katabatic flows and their impact on the wind resource will be studied
using mesoscale modelling and microscale downscaling. |