Energiforsyning i Arktis – hvilken vej vælger Grønland? - Artek ...

can be estimated for a given wind turbine
when can be the estimated wind resource for a is given known. wind turbine
when the wind resource is known.
The energy extracted from a wind turbine
comes The energy from extracted extracting from some a of wind the turbine kinetic
energy comes from contained extracting in the some wind. of Imaging the kinetic an
area, energy A, contained perpendicular in the to wind. the wind Imaging velocity an
as area, shown A, perpendicular in Figure 1 to the wind velocity
as shown in Figure 1
Figure 1: Volume of air that has travelled
through Figure 1: the Volume area, A, of with air that a speed has travelled of Vo in
time through Δt. the area, A, with a speed of Vo in
time Δt.
The mass flow [kg/s ], that travel through
this The area mass with flow a speed [kg/s of ], Vo that is travel through
this area with a speed of Vo is
(1)
(1)
where ρ denotes the air density slightly
depending on temperature and atmospheric
pressure but approximately 1.2 kg/m 3 where ρ denotes the air density slightly
depending on temperature and atmospheric
pressure but approximately 1.2 kg/m
. For a
large wind turbine rotor with a diameter of
90 m and wind speed of 10 m/s the mass
flow is around 76 tons/s. The kinetic
energy, , contained in the air volume
shown in Figure 1 is
(2)
and thus the available power (provided that
the wind speed could be reduced to 0 m/s)
3 . For a
large wind turbine rotor with a diameter of
90 m and wind speed of 10 m/s the mass
flow is around 76 tons/s. The kinetic
energy, , contained in the air volume
shown in Figure 1 is
(2)
and thus the available power (provided that
the wind speed could be reduced to 0 m/s)
(3)
(3)
Equation (3) is very important since it tells
us Equation that (3) the is available very important energy since per it time tells
depends us that on the the available third power energy of per the wind time
speed. depends As on an example the third a power site where of the wind
speed speed. is As 80% an example of a neighbouring a site where place the wind will
produce speed is only 80% 50% of a of neighbouring that neighbouring place site. will
Therefore produce only the 50% economy of that of neighbouring a potential wind site.
turbine Therefore depends the economy strongly of a on potential the wind
resource. turbine depends strongly on the wind
resource.
8
The available wind resources in 5
settlements The available and in wind Sisimiut resources was estimated in in 5
the settlements previously and in mentioned Sisimiut was two estimated projects, in
Fyrtårnsbygd-083 the previously mentioned Sarfannguaq two [1] projects, and
Projekt Fyrtårnsbygd-083 Vind- og Solenergi Sarfannguaq i Uummannaq [1] and [2]
by Projekt buying Vind- and og Solenergi installing i Uummannaq meteorological [2]
masts by buying at the and six sites installing shown in meteorological
Figure 2. In
a masts report at the from six the sites Danish shown in Meteorological
Figure 2. In
Institute a report DMI from [3] the a general Danish Meteorological
description of
the Institute climate DMI in [3] Greenland a general including description wind of is
given. the climate The in southern Greenland part including of Greenland wind is
touches given. The the southern westerlies part of Greenland located
approximately touches the between westerlies 35 and 65 degrees located
latitude. approximately The remaining between part 35 and of Greenland, 65 degrees is
located latitude. in The a remaining much calmer part of wind Greenland, climate. is
However, located in local a much phenomena, calmer wind such climate. as e.g.
catabatic However, winds local phenomena, and complex such topography as e.g.
also catabatic results winds in sites and with complex higher wind topography speeds.
Local also results experience in sites was with used higher when wind deciding speeds.
the Local location experience of the was six met used masts. when deciding
the location of the six met masts.
Figure 2: Placement of 6 10 m met masts
from Figure NRG. 2: Placement of 6 10 m met masts
from NRG.
The results from collecting data from the six
masts, The results see from [4], collecting is that data only from Sisimiut,
the six
masts, see [4], is that only Sisimiut,