Photovoltaic is the direct conversion of
sunlight into electricity using devices made of thin semiconductors layers;
these devices are called solar cells and a PV module consists of a number of
cells connected together. The peak output power of a module, defined as the
power delivered at an irradiation of 1000 W/m2 at 25° C, ranges from 30 to 120
W. The PV modules can form PV systems when they are connected together.
PV modules concentrates the incident light
onto photovoltaic cells. The cells can be divided in crystalline or thin film.
Unfortunately, the investment cost restricts
the application in large stations and individual or grid connected systems have
generally a nominal power between 50 Wp and 10 kWp. Thanks to a national policy,
French overseas department developed a lot of installation.
Active solar thermal energy systems of low
temperature use an energy collector, especially suitable for heating water for
human use and heating. The main components are the solar collector, a storage
system and the distribution or consumption system.
The basic element, the collector, contains an
absorber which converts the incident solar radiation into collected energy;
later on, the energy is transferred to the water for transport directly to the
load or to isolated tanks for later use.
A family consisting in four members uses 200
litres. of hot water a day. In Crete island and Cyprus these systems are very
used and equipped each house and building.
The machines that transform wind energy in a
usable one are called wind turbines or generators, and its power ranges from a
few watts to megawatts. The main generated energy is mechanical, but it can be
transformed to electrical with a gearbox and an electrical generator.
Wind systems available commercially at present
are reliable intermediate size two or three blades horizontal axis turbines,
with rotors diameters in the range of 30 to 60 meters and with power ratings in
the range 300 to 1 500 kW. They are cost competitive if operated under the most
suitable wind regime.
In areas where both environmental conditions
meet (plenty of hours of sunshine and high wind speed), a hybrid plant could be
made, assuring a better performance during more time.
A backup conventional system should be
supplemented to meet daily loads during periods without sunshine or under bad
weather conditions.
In the case that a hotel or urbanisation
decides to make the investment on their own, there is no need of a backup
system, as the energy in extreme cases will be supplied by the grid.
When the energy generation exceeds the needs
of the tourists lodged in the building, the extra energy generated will be sold
to the electric company.
Biomass is the organic part that comes from
animal, vegetal and micro organism wastes, that can be converted in usable
energy or products for other purposes.
Considering biomass as an energy source, the
one produced by photosynthetic organisms capable of transforming solar in
chemical energy is very interesting.
The most used resources for biomass production
in Europe are agricultural wastes. In overseas islands, the "bagasse"
waste of the sugar cane is often used.
Nowadays, wave energy is being investigated
and developed in a major way in Europe. The usage of a proved technology and the
advantages of natural resources make the use of wave energy profitable,
specially in energetically isolated areas.
Several plants are now working in several
countries. The generated energy is converted in electric and potential energy or
high pressures for seawater desalination, depending on the demand.
The costs of obtaining energy will be reduced
to a minimum by using the places with a maximum wave surge concentration,
setting systems in breakwaters and taking advantage of the existing
infrastructure.
There are places in our planet where huge
steam accumulation at a high temperature happens, and it would allow the
movement of steam turbines for electrical production.
There is a thermal station in Laderello (Italy)
that produces a third of the energy generated by a power station. There are
other plants in places like New Zealand and France with La Réunion overseas
department.
For centuries, the sails of windmills caught
the wind that guaranteed fertility in most of Mediterranean islands. These same
winds also helped to pump water to create abundance and brought the sea inland
and, thus, with the aid of the sun, helped to crystallise the salt, bringing
fame to islands as flourishing centres on the powerful salt route. Small
waterfalls were widely harnessed in remote areas to guarantee the survival of
the local people.
This is just an idea of the long adventure of
survival that islands have lived, cleverly harnessing their few and fragile
resources. Throughout time, all over the world, island peoples have always had
to develop ingenious ways of harnessing the sun, the wind and the water at their
disposal.
We only have to look at any of the wide world
islands to realise that the traditional house is always an incredible compendium
of passive solutions adapted to the specific conditions of each location to
overcome the hardships of the climate and the isolation.
That is why we can talk of an island strategy
to promote renewable energy sources on the threshold of this third millennium,
and this strategy should be understood as a mere continuity of the inherent
tradition of each island.
The new technologies seem to have been
designed by islanders. The traditional limitations in the energy field like
distance from the major grids, small scale, distribution difficulties and the
lack of large conventional markets, are more than off-set by the extreme
abundance of renewable energy sources, and the incredible adaptability and
capacity of integration of renewable energy technologies; factors that are in
sharp contrast with the progressive inefficiency and high cost of conventional
energy systems in island regions.
In fact, we would go as far as to say that
islands have become genuine laboratories of the future of energy sustainability.
The weight of energy costs, along with the enormous social and environmental
implications of using energy in such vulnerable regions, is clearly tipping the
scales.
The area in question includes a population of
over thirteen million islanders and a surface area of almost 5% of the European
Union.
This view is of enormous importance at a time
when the Green Paper "Towards a European strategy for the security of
energy supply" is under discussion. In this context, the subject of the
islands will have to be addressed and tackled in accordance with its importance
and the new requirements that define the island factor and how it differentiates
islands from the mainland.
Nowadays, sustainable development for European
islands cannot be understood without relating energy aspects with tourism or
water production. The seasonal nature of tourism and the fact that it requires
services of this kind to be so much larger than those required by the resident
population, however adapted their development may be, represents a serious
headache for energy supply. More than fifty million Europeans choose island
destinations for their holidays, thus creating scenarios that were unthinkable
up until now. The data brings us face to face with a reality that cannot be
hidden. This reality can be summed up by saying that the Greek islands receive
more tourists than Portugal; the Balearic Islands has twice as many tourists as
Brazil and the Canary Islands receive twice as many tourists as South Africa,
the great emerging destination of Africa.
A report highlights the need for community
policy on island regions to help promote the rational use of energy, along with
a determined decision to opt for renewable, stressing the fact that tourism
distorts the energy balance of many islands by up to 600%.
This same equation can be seen in the
water-energy tandem. Limited water resources have forced many islands to make
the leap to desalination to quench their growing thirst. Islands have started to
measure water in terms of units of energy.
In this extremely variable framework, energy
options take on a fundamental strategic value for islands, especially with
regard to the aspects of supply costs, quality and security. If we add the
environmental dimension, where islands cannot afford the excessive externalities
of conventional systems, in areas where the environment and the landscape are
the principle factor of value added for their future survival, we come to the
conclusion that renewable energy sources are not an option, they are the only
reasonable path to follow in the future.
Islands have made a start. In the face of this
situation, overall European forecasts have been exceeded. Islands no longer talk
about 12% RES; they are starting to design 100% RES systems for the future. And
all of these solutions and designs are based on real projects and strategies.
European islands have, therefore, arrived at
an important moment in their evolution. Political will, technological
development and the terms of a sensible economic discourse based on sustainable
development make it advisable to open the gates wide to this great idea of
energy self-sufficiency for islands in the third millennium.
Photo TOTAL ENERGIE
A
large scale RES implementation towards 100%
The
global European RES policy
Institutions like the European
Commission, UNESCO,
the World Bank
etc. have a great role in promoting the harnessing of the natural resources for
the well-being of human society. Major initiatives have long been taken towards
this goal and great progress has been achieved in recent years.
In Europe it all started in 1996 with a Green
Paper followed by a White Paper and an action Plan for a Community strategy on
renewable energy sources. This paper contains a comprehensive set of measures to
attain the objective of 12% for the contribution of renewable sources to the EU
energy consumption by the year 2010.
A campaign for Take-off was launched as an
essential part of this action. The Commission believes that an early and visible
stimulus to the strategy would accelerate the necessary trend towards increased
investment in key renewable technologies.
The EU Parliament in particular, took a
spectacular initiative at the end of 1998, in favour of Renewable Energy
Technologies by assigning 60% of the 1999 RD budget inside the 5th Framework
Programme to the renewable energy sector.
Additional sources of funding, necessary to
reach the objectives of the White Paper, should come from national energy
programmes and schemes as well as from private sources.
The islands context
and application
In recent decades, the foundations for
inter-island co-operation have been laid at many different levels. New island
options must be clearly and independently defined within the framework of
globalisation, based on the premise that safeguarding our natural heritage and
the natural and cultural diversity of islands is a basic asset in the
construction of the future.
The island world encompasses territories that
are characterised by their extreme diversity and complexity. Remote archipelagos
or islands that lie close to the mainland, some with just a few dozen square
kilometres of land to the largest islands, but all with one common denominator:
In the area of energy, and indeed in many other areas, islands have an enormous
variety of circumstances. Their extreme diversity and singular nature are what
differentiate them in a world wide context.
In this context, it is a major milestone for
reinforcing a common policy to promote energy sustainability in island regions.
In the Minorca Conference, island
representatives stated unequivocally that "All energy sources, other than
renewable energies, should be considered as provisional solutions for solving
the energy problems of the islands in the long term. "No other regional or
world wide forum has ever mooted such a daring alternative as this. And that is
precisely what the island factor is; we have different conditions and resources,
our problems are very different and, therefore, we need specific strategies to
tackle them.
The option of using renewable energy sources
to the maximum is presently a real objective for islands, but, there is a clear
determination to put the theory into practise. Sustainable energy in the islands
already has well defined strategies and actions. Islands are in a position to
promote a clean and distinct energy strategy, based on the features that
distinguish them from the mainland and its real potential for change.
Distinguishing features
of the island energy factor
The external dependence of islands in energy
matters, is a factor that determines the basic aspects of their development. In
most cases, especially in small and medium-sized islands, energy products
account for over 15% of all island imports. The cost of electricity production
in islands can soar above the same cost in other regions.
Small and medium-sized islands encounter costs
that are between four and twenty times greater than on the mainland, in cases
where there is no cable or gas pipe line connections with the mainland. But it
is not just electricity production that is excessively expensive, in many
places, energy consumption by the transport sector alone can account for over
60% of the energy balance. These figures in themselves explain shortages of
supplies in many small islands, or the fact that they have to bear an
unacceptable financial burden to survive.
At best, excessive specialisation of most
island economies often forces them to install over-sized energy capacity, as
there are other determining factors like acute seasonal peaks and troughs in
consumption, abrupt changes in demand or greater territorial fragmentation than
in other regions.
The environmental impacts produced by
conventional energy sources and technologies are more far reaching than on the
mainland, due to the fragile and vulnerable nature of island regions.
Concerning energy efficiency, the systematic
import of rigid mainland models of production and consumption generally adapt
very poorly to the energy sources used. Islands cannot support conventional
energy models in either physical or economic terms, and we should not forget
that this kind of mistake has caused really serious problems in the past, in
fact part of the work we face in the next few years is to solve these problems.
Arguments in favour
of island energy sustainability
Most islands have excellent renewable energy
resources available in sufficient abundance to guarantee very often, a large
degree of self-sufficiency in energy terms. These are currently under exploited
in comparison with their real potential.
Much of the energy forecasting and planning
work done in recent years in island regions indicate that potential energy
sustainability is highly feasible. The example of wind energy shows that, in an
international context, the largest growth in wind farms has taken place in
islands.
The scale of islands allows for highly
modulated energy planning, with renewable energies accounting for a large
proportion, a factor that must be considered as a value added aspect. It is
hardly surprising, therefore, that projects with a heavy bias in favour of RES
are implemented in islands, giving rise to the first initiatives promoting 100%
renewable energy. This is a possibility that would have been unthinkable a few
years ago, but which has been favoured by technological advances and by a firm
will to change the existing model. But, along with the rediscovery of the great
potential of RES, one of the main challenges for islands is achieving an
acceptable level of energy efficiency in practically the entire range of domains
and activities.
Islands are also excellent laboratories for
researching and developing appropriate, clean and low impact energy models. The
scale of islands makes it possible to introduce and test new solutions within an
acceptable time scale.
Overcoming island
barriers
One of the main lessons to have been learned
from the past is that the barriers impeding the development of sustainable
island energy are not exactly of a technological nature. The obstacles impeding
the implementation of renewable energies are political, financial, legal and
training barriers that must be overcome in order to create a favourable and
technical and social – economic climate, especially in the area of comparing
them with conventional energy sources.
The lack of differentiated energy policies for
island regions at all the main levels of decision making: local, national and
international, is another major handicap. Sustainable energy strategies for
island states and regions must go beyond merely introducing conventional energy
policies. One of the main pillars of island energy policies must be to establish
incentive mechanisms and instruments to foster energy saving and
rationalisation. Specific frameworks that create favourable conditions for
overcoming these shortages must also be promoted. In this work, the
international agencies involved can make a powerful contribution toward this
essential change.
It is also surprising to see the enormous
deficit that exists in differentiated market strategies and initiatives, making
it impossible to convert the islands into one of the greatest real niches in the
renewable market. Individually, islands generally do not achieve an acceptable
critical mass, but as a whole, they are the largest current gateways to the
great RES market of this XXI century.
Current trends in energy policy are basically
aimed at achieving greater competitive plan. A consensus must be reached in the
long term however, on the essential outlines of a common energy strategy for the
EU that also considers other factors: respect for the environment, job creation
and assuring supply. One can not forget the commitments the EU assumed in Kyoto,
with regard to reducing greenhouse gas emissions. Energy efficiency and
renewable energies represent one of the few really effective options for
reducing CO2 emissions.
State
of art on RES using and application in island territories
Introduction
The growth of the population during the last
decade has created a debate about the possibility of maintaining the development
and the quantity of natural resources available in our planet. The problems
caused by the increase in the consumption are basically related to the
settlement of cities and tourist areas, which have produced other consequences
involving pollution, lack of natural resources, a bigger density of population
and many more concerns.
The degradation of nature has been caused by
the systematic exploitation of the natural resources and the use of
non-renewable sources such as petroleum and coal. That type of energy has
clearly contributed to degrade the planet plus originating energy dependence.
Moreover, these conventional sources are finite, as explained in the following
table:
DURATION OF KNOWN RESERVES
DURATION OF TOTAL (KNOW AND UNKNOWN)
RESERVES
OIL
49 Years
72 Years
NATURAL GAS
68 Years
134 Years
COAL
262 Years
617 Years
URANIUM
60 Years
230 Years
A closer look at this table reveals that
actual consumption habits will deplete all reserves in the near future. The main
result will be an increase of energy cost, thus fast impoverishment and a higher
pressure on the environment.
As a fact, all these considerations are even
greater when applied to island regions, due to their fragile ecosystems and lack
of conventional energy sources. Their specific economy usually focussed on
particular sectors (like agriculture or tourism) increase their vulnerability to
the consequences of energy consumption related to the use of fossil fuels. The
development of renewable energy sources using and desalination systems are the
only way to guarantee a sustainable future for insular systems.
Island specific
needs
Water
Several European and Mediterranean Countries
have water problems, but it gets worse when referring to southern islands and
municipalities, mainly devoted to tourism. The problem there is worst, because
tourism demands an endless supply and, because of the leisure facilities, such
as swimming pools, golf courses and greens, even when there is enough water,
there are high losses in mains supply, which is often polluted or salted.
For all these reasons, there is a growing
necessity for the utilisation of desalination plants, due to the increase of the
consumption and the lack of water that central and southern countries suffer
originated not only by the inhabitants but by tourists; the prospects for the
use of product water as an energy storage system along with the rising
introduction of renewable energies make it easier to implement systems to cover
the urgent necessity of fresh water. Moreover, the energy for water supply in
Mediterranean countries is very expensive, and most of the time it depends on
fossil fuels, increasing pollution and dependence from the exterior. Pollution
should be avoided, as tourism may escape to other unexplored targets once the
environment is harmed.
Nowadays, PV systems are quite expensive in
larger plants compared to conventional energy sources and other renewable, like
wind energy. Nevertheless, it perfectly fits small applications of no more than
2 kW, making it the adequate power supply for direct distillation systems in
small and local applications.
On the other hand, wind energy is a high
competitive form of producing energy, even in islands with a low average wind
speed. The usage of wind turbines to power medium sized desalination plants is
perfect, and several pilot plants are being developed under the framework of
some European programs, as well as hybrid systems using PV panels and wind
generators to produce fresh water.
Finally, these desalination plants could also
be connected to the grid, which is the easiest approach. Anyway, in order to
avoid pollution, a parallel solution consisting in the installation of RES
generation systems connected directly to the grid should be applied.
Desalination plants
Because of the lack of water, islands should
take advantage of their natural resources. With this resolution, together with
the installation of desalination plants, the quantity of water available will be
increased and the pollution caused by fossil fuels reduced. Desalination
is the separation of dissolved impurities from water. Part of that water is
recovered in a product stream in a purer form.
Desalination processes can be divided into two
large groups: Distillation and membrane systems. Distillation is used almost
exclusively for seawater desalination. Membrane systems include Electro dialysis
(brackish water) and reverse osmosis (both brackish and sea water)
As the lack of water and its impurity is a
problem that is affecting people already, desalination systems will be of
significant importance in the near future. Reverse Osmosis (RO) in particular
will be of special interest on islands and coastal sites, because of the
availability of sea water and the avoidance of costs that a well and a pumping
system will take, in case that there is a brackish water available.
The RES solution on
islands
General
considerations
The fear of a polluted environment is not
exclusive of a specific sector of society. Many organisations and groups have
expressed their concern on these matters, as well as their belief that renewable
energies are the solution for a sustainable development.
Besides, the percentage of the Gross Domestic
Product used for Primal Energy Supply, considering a fixed price of 20$ per
barrel of crude, has been decreasing from 5% in 1970 to 3,8% in 1995; it is
expected to follow this trend, reaching 3% in 2020. This reduction is mainly due
to the change in the economy towards the service sector.
Two alternatives are suitable for islands to
be applied: the first one is the installation of large Renewable Energy Plants
to centralise the distribution and generation of energy, working together with
the traditional stations already working. The other one will be the local and
individual application in buildings and dwellings.
If a compromise is made with decision makers,
involving all sectors, 100% of the energy demand could be covered with RES.
In the other hand, the rational use of energy
is a complementary and necessary action in phase with users. Instead of using
the traditional bulb lights, low consume ones (20% of the normal consumption) or
halogen lamps will be used. It saves 0,5 ton of CO2 to be emitted to the
atmosphere to change a 100 w. traditional light for a low consume. Photoelectric
controls switch off unnecessary lights when not required, producing a saving
between 10 and 80%.
Main findings
Around the world, a few islands already have
taken the decision to become 100% RES community in a near future , Samsoe
and Aero from Denmark, Gotland
from Suede and others in the Caribbean region like the French island La Desirade.
Some of them produce already more than 50% of their electricity from RES like
Fiji and Pellworn (Germany).
Most of the southern islands are using solar
water heaters on a very large scale (i.e. Barbados and Cyprus).
Islands with very big utilisation of RES for
electricity production are mainly utilising hydropower and wind power. That is
true European islands are in the North Atlantic Ocean but the Mediterranean sea
and the Caribbean sea own also a few of overseas European island for PV
applications.
The next chart indicates the level of RES
penetration for electricity production in a few European islands:
ISLAND
COUNTRY
% of electricity from RES
Type of RES
Area (km²)
Population
Density
LA DESIRADE
F
100
W
70
1600
23
SAMSOE
D
75
W
114
4400
39
PELLWORN
G
66
W/PV
37
900
24
REUNION
F
56
H/B
2512
653000
260
FLORES
P
43
H/B
142
4300
30
SAO MIGUEL
P
38
G/H
747
126000
169
FAEROE
D
35
H/W
1400
48000
34
MARIE GALANTE
F
30
W
158
13500
85
CORSE
F
40
H/W
8721
250000
29
MIQUELON
F
30
W
216
600
3
RARUTU
F
20
W
243
2000
8
MADEIRA
P
17
H/W
765
248300
325
ASCENSION
UK
16
W
82
1100
13
GOTLAND
S
15
W
3140
58000
18
ILE DES PINS
F
15
W
141
1700
12
ST HELENA
UK
13
W
122
5600
46
AEROE
D
13
W
90
7600
84
SAO JORGE
P
10
W
246
10200
41
GUADELOUPE
F
12
B/H/G/W/PV
1500
400000
267
FUERTEN VENTURA
S
9
W
1660
41600
25
GRACIOSA
P
7
W
61
5200
85
CRETE
GR
6
W/PV
8260
540000
65
LA PALMA
S
6
W/H
708
81500
115
PORTO SANTO
P
6
W
42
5000
119
EL HIERRO
S
5
W
269
8400
31
GRAND CANARY
S
4
W
1560
714000
458
LANZAROTE
S
4
W
846
77200
91
SANTA MARIA
P
3
W
97
6000
62
CARACAO
NL
2
W
444
144000
324
TENERIFE
S
2
W/H
2034
666000
327
FAIAL
P
1
H
170
15000
88
TOTAL OR AVERAGE
23%
36 597
4 140 700
113
RES codification: B Biomas, W Wind power, H
Hydropower, G Geothermal, PV photovoltaic
As conclusion, we can imagine that all these
European islands represent an only one imaginary country of 4 millions of
inhabitants on 40 thousand square meters with around 25% electricity production
coming from RES.
This fact proves how islands are a fertile
field for RES promotion and penetration but also that the promotion of RES can
boost the European Commission target of 100% sustainable communities.
RES
a strategic stake for insular territories
The problematic
The last few years has shown an increased
focus of RES on islands.
However in nearby all the islands around the
world, and specifically in the European area, the potential for RES is not yet
tapped.
For the majority of islands expensive and
environmentally problematic fossil fuels are still the only energy sources used.
Recent disasters (Galapagos, Sein, …) prove
if necessary how these fuel purchasing can be dangerous for the landscape and
its faun.
One of the reasons for the under exploitation
of RES is lack of knowledge, awareness and co-operation about the islands around
the world that today have actually substantial utilisation and experiences in
regard to RES using.
The very big potential of RES applications on
islands, the maturation of these appropriate technologies and their
competitiveness especially in the insular context, organisational models for
planning exchanges, implementation and financial schemes experimenting, … must
be boosted.
The answer
Consequently, one major objective of the RES
promotion is to boosted that RES on islands with the aim of 100% sustainability
is a feasible option in regard to environment, technology, organisation and
economy.
An other main objective is to engage global
co-operation and networking among RES most involved islands and interested ones,
with a strong ambition in regard to RES may significantly strengthen the role of
island population, utilities and administrative entities as global forerunners
for the RES.
Then, last but not least, it would be a
formidable tool for European
Union energy policy in order to reach the White Paper
objectives.
Today, nearly all islands in the world are
totally dependant on expensive and environmentally problematic fossil fuels for
their energy needs.
But they have an unique potential for RES:
A competitive economic situation
Good renewable energy resources thanks to the wind, the sun
or the sea
Generally positive attitude and awareness of its population
Highly visible laboratory for technology
They can be an example of organisational
methods or financing and serve as demonstration projects for nations.
At the same time, there is a need to
demonstrate RES in a large scale, integrated and organised form. This is not
possible on mainland, therefore the project can show a renewable energy world
wide promotion.
