Coas al P ocesses
111
1 5
Spa ial a iabili y
o
wa e ene gy esou ces
a ound he Cana y Islands
H.
Chi i,
M.
Pacheco &
G.
Rod íguez
De
pa am
en o de
Fí
sic
a,
Uni e s
idad
de
las
Palma
s
de
G an
C
ana ia
, Spain
Abs ac
Spa ial a iabili y
o
wa e ene gy esou ce a ound he coas al wa e s
o
he
Cana y A chipelago
is
assessed
by
using a long- e m da a se de i ed
by
means
o
hindcas ing echniques. Resul s e ea(
he
exis ence
o
la ge di e ences
in
he
ene ge ic con en a ailable
in
di e en zones
o
he a chipelago, mainly du ing
sp ing
and
au umn. A eas wi h a highe wa e powe
le e(
a e he no h edge
o
Lanza o e, wes e n side
o
Lanza o e
and
Fue e en u a, no h
and
no hwes
in
La
Palma
and
El
Hie o,
as
well
as
he no h coas
o
Tene i e. The a ailable
ene gy po en ial sligh ly dec eases
in
he no h side
o
G an
Cana ia
and
La
Gome a.
In
gene al, only no h
and
wes edges
o
he a chipelago du ing win e
and
au umn show p ac ica( in e es
o
he
use
o
exis ing wa e ene gy
con e sion de ices.
Keywo
d
s:
wa e ene
gy,
spa ial a iabi/i
y,
wa e hindcas in
g,
Cana1
y /s and
s.
1 In oduc ion
The sea ch
o
enewable ene gy sou ces o e ing clean al ema i es
o
scan y,
expensi e,
and
en i onmen ally p oblema ic ossil
uels
ep esen s a i al
challenge
o
humankind. The esea ch
in
his
ield
ha
s
been
du ing a long ime
almos exclusi ely ocused
on
he de elopmen
o
sola
and
wind sou ces.
Howe e , sola ene gy
is
s o ed
in
he sea
as
wa es, cu en s,
and
hea . Tha i
s,
ene gy
in
he ocean
is
much
mo e concen a ed han
in
h
e di ec sola adia ion
and
in
he wind.
Small islands and a chipelagos
in
he wo ld a e almos o ally dependen
on
ossil uels
o
mee hei ene ge ic needs. Ne e heless,
in
gene al, islands ha e a
unique po en ial o enewable ene gy (i.e
.,
Jensen [ 1
]).
Tha
is
, a compe i i e
•
WIT T ansac ions on Ecology and
h
e En i onme
n
, Vol 169,
www
.wi p ess.com, ISSN 1743-354 1 (on-line)
doi: 10.2495/
CP
I 30021
2013 WIT P ess
1 6 Coas al P ocesses
111
economic si ua ion o enewable ene gy echnologies, good enewable ene gy
esou ces, posi i e a i ude owa ds enewable ene gy. Fu he mo e, he e
is
a
need o demons a e easibili y
o
enewable ene gy
in
a la ge-scale, in eg a ed
and o ganised o m. The e o e islands a e e y impo an and in e es ing o he
p omo ion
o
enewable ene gy wo ld-wide and almos all
o
he ma u e
enewable ene gy echnologies, mainly sola and wind, ha e been u ilised o
elec ici y p oduc ion
in
hese a eas.
Wind-gene a ed g a i y wa es
in
he sea su ace cons i u e he highes ene gy
densi y
o
all enewable ene gy esou ces (i.e., Clemen e
al.
[2]). This ac has
led scien is s and enginee s o de elop a wide a ie y
o
de ices o hamess his
esou ce by means
o
i s con e sion in o elec ical ene gy. An up- o-da e e iew
o
he s a e-o - he-a
in
his challenging a ea
is
p o ided by C uz
(3]
.
Nowadays, his echnology
is
no s ill a an ad anced s age
o
de elopmen .
Howe e , i has a ac ed inc easing in e es
o
esea che s du ing he pas ew
decades as a po en ial ene gy esou ce o small islands.
ln
pa icula , since he
pionee ing wo k
o
Mollison (4], Cana y a chipelago, as well as Azo es and
Madei a, ha e been conside ed as an in e es ing zone o exploi wa e ene gy as a
easible al ema i e o con en ional ene gy esou ces. Thus, se e al au ho s ha e
conduc ed s udies o assess he po en ial wa e ene gy a ailable o so ne speci ic
islands
(i
.
e.
, Rod íguez e
al
. [5], Iglesias and Ca ballo
(6
,
7]
, Sie a (8]).
The main goal
o he
p esen s udy
is
o ex end he assessmen
o he
po en ial
a ailabili y
o
wa e ene gy o all he islands
o
he Cana y a chipelago, wi h
special emphasis on he spa ial a iabili y
o his
esou ce.
The pape
is
s uc u ed as ollows. The s udy a ea and he da a base used
in
he s udy a e p esen ed
in
sec ion 2. Gene al no ions on he me hodology o
es ima e he wa e ene gy lux a e b ie ly ou lined
in
sec ion 3. Nex ,
in
sec ion 4,
he discussion
o
esul s de i ed om he analysis
o
he da a se
is
p esen ed.
Conclusions d awn om esul s a e summa ised
in
sec ion 5.
2 S udy
a ea
and
da a
se
The Cana y !s ands a e an a chipelago
o
se en majo olcanic islands
in
he
A lan ic Ocean, loca ed abou 100
Km
o he
A ican coas (27.5° N - 29.5º N,
13º
W-18
.5º W) (Fig. 1 ). G an Cana ia and Tene i e ep esen he wo mos
popula ed islands, adding oge he mo e han 80%
o
o al inhabi an s. The es
o
he esiden s a e mainly concen a ed
in
Fue e en u a, Lanza o e and La
Palma, while he mino islands
o
El
Hie o and La Gome a a e ba ely popula ed.
A quick look a Figu e 1 e eals he complex geome y
o he
islands coas , he
p oximi y be ween hem, and o he A ican con inen . Ano he impo an ac o
o conside
is
he al i ude
o
he islands. The al i ude
in
i e
o
he se en islands
is
o e l 500m, wi h 3700m
in
Tene i e, while Lanza o e and Fue e en u a a e
conside ably la .
The es ima ion
o
he wa e ene gy po en ial a ound Cana y lslands has been
ca ied ou by using ime se ies
o
cha ac e is ic wa e pa ame e s ob ained by
means
o
a hindcas ing app oach. The W AM nume ical model p o ides he
WIT T ansac
io
ns on Ecology and
h
e En i
o
nm
e
n
, Vol 169,
www.
wi
p ess.com, ISSN 1
743
-354 1 (on-line) 2013 WIT P ess
Coas al P ocesses
111
1 7
29
.
s~~--~--~--~--~~-~--~~-~--~---~__,o-_.___,
___
~-~
29
-8
28.5
:§
:'i
27
.5 ,_
..
- 19
Figu e 1:
-•
--
!
--:
--
·
·---··--··
-18
-
17
-
16
-
15
-1 4
-1J
Long
i u
de
(º)
Map
o he
Cana y lslands and loca ion
o he
hindcas poin s.
di ec ional spec um a each
one
o
he poin s ma ked
in
Fig.
1.
F om hese,
cha ac e is ic pa ame e s o e alua e
wa e
powe
esou ce can be de i ed.
The
WAM
model is a
3'd
gene a ion spec al
wa e
model which sol es he
spec al
wa e
ac ion balance equa ion wi hou any a p io i assump ion on he
wa e spec um
shape
by using a ini e-di e ence scheme. The wa e ield is
desc ibed by he wo-dimensional
wa e
ac ion densi y spec um, N(w,{J), whe e
w
is
he angula
wa e
equency and
()
is
he wa e di ec ion. The model uses
wa e ac ion densi y spec um because ac ion densi y
is
conse ed in he p esence
o
cu en s.
The
spec al ac ion balance equa ion eads
aN
+ a(CgxN) +
a(CgyN)
+ a(CwN) +
a(C9N)
=
~
(1)
a
ax
ay
aw
ae
w
The
i s e n on
he
le -hand side ep esen s
he
local a e
o
change
o
wa e
ac ion densi y
in
ime
;
he
second and hi d e ns s and o he p opaga ion
o
wa e ac ion
o e
geog aphical space, wi h p opaga ion eloci ies C
g.
•·
C
KY>
C
a
C8
in
he geog aphical and spec al space, espec i ely.
The
e n
a
he igh hand
side
is
he sou ce unc ion, including he e ec s
o
gene a ion, dissipa ion, non-
linea in e ac ions, and bo om ic ion dissipa ion. De ails abou
WAM
can be
ound
in
Komen e
al.
[9].
The
WAM
model
was
used o p o ide
he
44-yea
hindcas wa e clima e
da abase ( 1958-2001) om he Eu opean HIPOCAS p ojec (see
Guedes
Soa es
[ 1
O]).
The
model
was
o ced by
he
ou pu
o
a high- esolu ion a mosphe ic
model
(REMO
egional a mosphe ic model).
The
HIPOCAS da abase was
gene a ed by unning
he
models on a g id co e ing he No h A lan ic wi h a
esolu ion
o
0.5° x 0.5° a om he coas and 0.25° x 0.25° close o his.
Tempo al esolu ion
is
3 hou s. De ails on he me hodology used o ob ain wa e
condi ions a any g id do a e gi en
in
Pila e al. [ 11]. Figu e 1 indica es he
posi ion
o he
65 poin s conside ed
in
he s udy, indica ed as ed do s.
3 Wa e ene gy lux es ima ion
The
wa e
ene gy lux,
powe
densi y,
pe
me e
o wa e
c es
is
gi en by
2
Joo
P =
pg
Jo
2
C
9
( ,
h)S( ,
8)d
d(}
•
WIT T ansac ions on Ecology and he En i onmen , Vol 169,
www.
wi
p ess.com, ISSN 1743-354 1 (on-line) 2013 WIT P ess
(1)
Coas al P oces
se
s
111
1 9
cons i u e a hi d kind
o
a ea, wi h he lowes alues
o
wa e powe , no
exceeding
12
kW/
n.
Yalues
o
a e age wa e powe o each cli na ic season a e shown
in
Figs 3-
6.
Du ing he sp ing (Fig. 3) he a eas wi h highe ene gy powe a ailable
a e no h and wes s ips
o
he a chipelago, pa icula ly he no h edge
o
Lanza o e and La Palma islands. The gene al dis ibu ion ollows he sa ne
pa em han ha
o
he annual a e age alues, wi h e y low alues
o
powe
in
he sou h and sou heas
o
he nain pa
o
he islands
(3-9
kW/ n), and
in e nedia e alues
in
he e naining a eas.
Figu e 4 illus a es he a e age wa e powe du ing su n ne . l e eals a
signi ican educ ion
o
he wa e ene gy po en ial
in
he en i e a chipelago.
A eas wi h la ge ene gy a ailabili y emain he same, bu now alues a e lowe
han
10
kW/
n.
Ene gy le els co esponding o au umn a e depic ed
in
Fig. 5. Du ing his
season, ene gy le els a e simila o hose es ima ed o he annual pe iod.
Howe e , powe alues
in
he a eas wi h a highe exposu e deg ee o wa e ields
app oaching om he N- NW di ec ional sec o a e compa a i ely highe .
In
he
no h and wes
o
La
Palma, as well as
in
he no h
o
Lanza o e wa e powe
le el eaches alues be ween 24 and 27 kW/m.
In
con as wi h he o he pe iods
o
he yea , du ing win e (Fig. 6) Cana y
lslands coas s ecei e a ela i ely heigh quan i y
o
wa e ene gy.
In
shel e ed
a eas by shadowing e ec s, le els
o
ene gy ollows been low, bu
in
he o he
pa s
o
he a chipelago he a ailable powe expe iences a conside able inc ease.
This
is
naximum he no hem and wes e n edges
o he
a chipelago, whe e wa e
powe alues inc eases be ween 75% and 80% wi h espec o he annual mean
alues. Zones wi h highe wa e ene gy powe a e loca ed no wes
o
La Palma,
wi h a powe le e( close o 40 kW/m, and o he no h
o
Lanza o e, whe e wa e
ene gy powe eaches alues
in
he ange
36-39
kW/
n
.
Resul s de i ed om he s udy e eals an app eciable spa ial a iabili y
in
he
wa e ene gy a ailabili y
in
he a chipelago. The easons o a so la ge a iabili y
a e di e se. A one hand, wa es can each he coas s
o
he islands o n any
di ec ion. Ne e heless, o a gi en di ec ion
o
app oach, wa es only i npac on
ha islands exposed o wa e ields co ning o n ha sec o and,
o
ha islands,
on
ly
he coas s o ien ed
in
he di ec ion
o
wa e a el. Tha
is
, so ne islands can
ac as a, pa ial
o
o al, ba ie agains so ne wa e condi ions o o he islands.
Fu he mo e, any island shel e s hei own coas s loca ed a he opposi e side
o
wa e app oaching. These e ec s
o
sel -blockage and nu ual-blockage depend
o a la ge ex en on he geo ne y and di nensions
o
each island. On he o he
hand, cha ac e is ics
o
wa e ields a eling owa d he islands depend
subs an ially
o he
di ec ional sec o o n which wa es app oach.
5 Concluding ema ks
Analysis
o
wa e ene gy po en ial a ound Cana y lslands e eals ha he e a e
la ge di e ences
in
he ene ge ic con en a ailable
in
di e en zones
o
he
iÍ
WIT T ansac
i
ons on Ecology and he En i onme
nl
, Vol 169,
www.wilp ess.com, ISSN 1
743
-35
41
(on-line) 2013 WIT P ess

•
~
~
~
=i
§.
~
~
~
""'
"' o
!'! =·
" o
o "
3 "'
• o
-"
~
gi
zo
-o
-.JOO
...
'<
Y'
"'
w"
"'
Q.
::
So
~"
o m
""
.!.. <
~
·
a
·
~::i
3
~
~
<
2.
°'
-'°
!El
"'
o
~
=i
~
2goN
28°N
27ºN
19"W 18"W
'!}
o
u
o '! i o
.,
lll
Palm3
'
¡;;,
· · · o o
o o o
(>
,.
o
,.,
e
'(
'
-
~
u " e
LA
n
Gom e
a
o
~
{
o o o (>
El
Hie o
o
(>
o
Figu e
2:
17"W
o o o
(>
Tene ·
i e
o
(>
o
o
o o
l
C.'l
na
i
a
16"W
o o
""
V
e
o o o
15"W
"''
"
Annual spa ial
di
s
i
bu
ion
o wa e
ene gy esou ce.
14"W
o o o
o
e
ue e e u a
k.Whn
1 3 - 6
6 - g
o g - 12
o 12 - 15
o
15
-
18
o 18 - 21
o 21 -
24
l<l
l
omel!! s
o 15
ll
!ll
N
J
:~
il
N
o
(")
o
~
~
"'O
o
(")
('O
"'
"'
('O
"'
•
~
~
~
-i
~
::;i
: :
Col
~
~
~
~
g g·
:;
~
• o
Vi
~
"'
o
zo
- o
.....JO::
....
'<
'-:'"
w =
"'
o.
:::
:;.
-"
o
n
= =
.!.. <
~
-
a
·
~
=
~
~
<
!:<.
.
: ::
'"
o
,
_,
:;:
:::;
[
29"N
28ºN
27"N
19°W
18oW
17"W
,.
, A
V V
o
~
o o o
(>
u
Paln
~
.
.,
(>
o
(>
o
:JY
'i
-
~
~
' :
..
1.·
_: .
o o o
(>
~
••
· .,
~
.
(>
'
'
.
.,.
,.
·
,
~
.,
·'
'·
o " o o -,,
,.,._
...
..
Gome a., Tene i e .
º
~
·
·
/ º º
'El Hie o o (> o o "
o <> o
16"W
o
o
o o o
--~
:~
~
~
C'
-~
o
o
o o
o
o
15"W
"
"
-'
o
Figu e 3: Spa ial dis ibu ion
o
wa e ene gy esou ce du ing sp ing.
14"W
o o
o
o
k
:V
im N
3 - 6
~
6 - 9
o
9-
12
o 12 - 15
o 15 - 18
1
n
o
~
o 18 - 21
"'
§.
"O
l<ll
ome l! s
~1
..,
o
o
16
ll
8'.l
()
w w
"'
"'
"'
"'
"'
-
N
•
~
~
~
::;
.
-1
~
·
~
~
g;
"'
o
~
=·
8 g
3 "'
• o
-"
~
gi
zo
- o
~22
~
"'
o.
:::
:;.
~"
o
T1
I.
~
:;· :;·
" o
~o
3
"
·ª
2:
"'
·
'°
o
N
o
~
-1
l
29"N
28ºN
27°N
19'W
o
o
La
Paln'
o
~
~
(
IHi:.. o
o
18"W
17"W
o
(>
o
(> o
.
Gome a
Tene i e
Cana1i
a
16"W
15"W
{~
o
14"W
o o o
o
ue e e l u a
k
'
/m
<3
3 - 6
6 - 9
o
9-
12
..1
Dm l'U
N
J
015.xl
60
90
Figu e 4: Spa ial dis ibu ion
o wa e
ene gy esou ce du ing summe
.
N
N
(")
o
~
§.
'"O
a
n
o
V>
V>
o
V>
..
~
~
~
::¡
~
·
~
"'d::::
(11
g;
~
!l
n o·
o "
..
3
~
;
~
VI(')
za
- o
~ !.2
l¡J
:,,
w"
V>
Q.
~
=-
~"
o m
""
.!...
<
=·
:::;
·
" o
-"
3
"
·ª
~
_$
"'
o
w
~
::¡
l
19"W
29°N
,,.,
o
'-/
o
...
-::i~
~
-
-
·
i
~
La
Pa
ln
•1
< .;· , ;
(>
,
o
o
'()
o
0
4,
o
El
H
ie o
o
(>
o
27°N
18"W 17"W 16"W 15"W
"
._,
o o o o o o
o º
i
o
o
~
~
-,~;..
~
i
-
-
~
o
o o
<>
'
·,~
""°
(>
o o o o
;,.;;
4)8p·_
--
~~
•
'S
~.
J.~~
~
...
~
o .;¡
~)
'
...
,,
;'
~
;:,~
.
'l? !:.
~,
o o
Go
n
e n Te
ne
e
o o
(>
o o ( >
~
~
G an o o o
Cana
ia
o o
Figu e
5:
Spa ial dis ibu ion
o wa e
ene gy esou ce du ing au umn.
o o o
o , o
--
~
:_
·
:
~...,
e
1
kW/m
o
3-6
6-9
o 9 - 12
1 o
12
-15
o
15
-18
o
18
-
21
o
21
-24
o
24
-27
14
1omse s
o
15
ll
llO
14"W
N
j
~
QO
(")
o
el
[
'"'O
a
(')
<>
Vl
Vl
<>
Vl
N
w