Figure. 1 POPULATION
In the period 1960/90 the world's energy
requirement has risen considerably.In 1960 the world used 3,3 Gtoe of energy
and in 1990 used 8,7 Gtoe,or an increase of 164 % with average increase
of 3,3 % p.a.Two main forces driving energy demand have been :population
growth and economic development.Thus between 1960 and 1990 world population
rose nearly 2,3 bilion,within the developing countries accounted for 87
% of this growth,increasing their share of world population from 68 % to
76 % in 1990(fig.1).
BILIONS
Figure. 1 POPULATION
But there are wide divergences in energy use.By far the largest energy consumers are industrialised countries-OECD and Central Eastern Europe.In 1990 these countries accounted for some 66 % of the world's energy consumption.Only one third of energy was consumed by the developing countries, as shown on fig.2. Also, energy use per capita is even more varied. At present the majority of the world' population uses less than 1,2 toe of energy per head(indeed many use less than a third of this);the developed countries use more than 7 toe per capita.
GToe
Figure 2 Energu requirement
We can see that the relative increase of wealth in the developing countries( the developing countrie's share of world economic output has grown from 26 % in 1960 to 34 % in 1990) has gone more into supporting population increase rather than into increasing the economic prosperity of individuals.The economic wealth per capita of the rich countries in 1960. was 7,2 times greater than that in the poor countries; by 1990 the ratio had increased to 7,5 to 10.In this sense the wealth gap between the rich and poor countries has widened.Looking ahead,population growth is likely to continue in the developing countries, although at a slower pace,form over 2,0 % p.a. in the 1960s down to 1,75 % in the 1980s.However,because the world' population has already passed the 5,4 bilion mark the actual growth of population will be the largest ever in a single 30-year period,despite declining fertility rates.Thus between 1990 and 2020 the UN anticipates 2,8 bilion more people and in period 2020 and 2050 a further 2,0 bilion people.UN forecasts are for a world population of some 10 bilion by 2050 and the figure could thereafter stabilise at somewhere 12 bilion by the second half of the 21 century.This will provide great chalenges,but also great opportunities for human imagination, adaptation and innovation.Given population growth,mainly concentrated in the developing countries,it will be dificult to increase rapidly the per capita use of energy.
Having in mind the development of world's population,the two fundamental challenges are crucial. Others exist, but the two appear to be:
- tbat the pathway to sustainable development still requires a universally accepted definition, and action is required to adapt to it, not only in the energy but also in many other sectors. The imperative priority remains for economic development, but the potential impact of such development on local and global environments equaily require honest and courageous protective action.
- ENVIRONMENTAL CONSTRAINTS TO ENERGY CONSUMPTION- Concern about the increase in greenhouse gases and potential global warming is verry intense today, with many studies of causes, impacts, responses and costs.It isn't expected that developed countries, much less the developing countries, will agree to limit significantly the consumption of fossil fuels (or the rate of deforestation) during the next one-two decade. It does seem likely that there will begin to develop some consensus on prospective impacts, responses and costs - as well as some consensus on how difficult it is to establish, by political means, the rates at which greenhouse gases are to be added to, or removed from the atmosphere.
- CESSATION OF OPEC DOMINATION-Today OPEC supply world energy market less than 40 %.It had been more than 60 % in the 70s.
- INTENSIVE RESEARCH OF ENERGY POTENTIALS
AND NEW TECHNOLOGIES - Techology is a potent weapon for achieving a transition
to a sustainable future.Much can be done to reduce the environmental impacts
of energy use.The technological efforts in the energy field are made in
three directions:to improve the efficiency with which we produce,transport
and use energy;to develop completely new energy systems and to reduce the
adverse environmental impacts of energy use. Commercial fossil fuels supplied
over three quarters of the world' total energy requirements in 1990,and
even though non fosill energy sources are expected to increase their share,fossil
fuel supplies will continue to meet the bulk of the world's energy requirement
for a long time to come.That's why we are in time of intensive research
of energy potentials. In the table 1 and 2 we have the world and OECD countries
energy potentials on the basis of World Energy Council estimates in 1990:
Fuel type Proven reserves Potentials Total
Convetional liquid fuel 150 145 295
Non-convetional liquid fuel 193 332 525
Total liquid fuels 343 477 820
Natural gas 141 279 420
Coal 606 2794 3400
Total fossil fuels 1090 3550 4640
URANIUM:
In thermal reactors 57 203 260
In fast reactors
3390
12150 15540
On a global basis, there appears to
be adequate energy supplies in useful forms at acceptable prices. Problems
will continue to arise because of the distribution and control of those
resources as compared with geographical patterns of use. There are also
difficulties in transport for oil and, to a lesser extent, for gas and
coal.
Table 2. Energy reserves and static life cycle in OECD countries
-----------------------------------------------------------------------------------------------
Fuel type
Proven reserves Compared
to world Static cycle
Gten
%
god
-----------------------------------------------------------------------------------------------
Coal 164,7 28,7 208
Oil 7,2 5,3 10
Natural gas 11,4 11 16
----------------------------------------------------------------------------------------------
WORLD ENERGY DEVELOPMENT UNTIL
THE YEAR 2020 AND THE YEAR 2050:
First let us remind ourselves of the basic analysis derived from the WEC Commission report "'Energy for Tomorrow's World" with its retained horizon year of 2020. Global population be that year will rise from today's 5.4 billion people to 8.0 billion (UN medium estimate) and global economic development will run at between 1.6% and 2.4% annual growth.
The four planning scenarios built into the Commission show increased energy demand of between 65 % and 95 % by 2020.What will this mean?
- It means that coal output will double to about 7 bilion tonnes per annum,more than twice th UK's or Canada's known total reserves.
- It means that gas demand will more than double, to reach some 4 trillion cubic metres, almost as much as the USA's current total gas reserves.
- It means that more electricity generating capacity will be built over the next 25 years than in the previous century.
- It means that 90% of this energy growth will take place in the currently defined developing countries particularly in Asia and in Latin America.
- It means that those developing countries wliich today consume 30% of the world's total energy will consume 50% by 2020 and probably 70% by 2100.
- It also means that by 2020 those same developing countries will emited more CO2 from fossil fuel burning than the CO2 emitrted by the whole of the industrialised world in 1990.
ENERGY IN THE YEAR 2050: why do
we need to look so far ahead?
We need to look ahead,to energy in the
the year 2050,for four reasons:
o world population will grow from 5.3
billion people today to something in the order of 10 billion by the middle
of the next century,
o meeting concern about climate warming
requires a time horizon reflecting the strategic nature of this problem.
o we need to decide on our research
and development strategies; and finally
o the decisions we wll take in the 1990s will largely determine our longer-term strategic responses well into the 21 st century.
From a policy point of view the requirement
is to ensure that actions which are developed for the short and medium
term are indeed coherent with longer term needs. The current energy system
does not always lend itself to prompt and flexible responses. But the continuation
of current trends in energy supply and use is not sustainable in the long
run. Three objectives, generally related to welfare, are critical to the
outlook for energy:
o economic growth
o affordable energy services
o environmental protection.
But there can be stresses between these
objectives.Two scenarios illustrate the nature of these stresses.Today
commercial energy consumption is in the order ot 8 billion tonnes of oil
equivalent (Gtoe) per year. lf energy eficiency improvements and changes
in the energy supply mix are effective then we might look to a world in
60 years' time consuming about 15 Gtoe, with most of the growth coming
from developing countries (table 3). However, continuing to implement current
approaches to those problems would lead us to a world consuming over 20
Gtoe.
These two illustrative energy futures
imply differing global priorities for these objectives, especcially between
regions. A conflict of aims is nowhere more likely, than in developing
countries where the continuing growth in population will mean an increasing
need for more and better services that require energy.Without such services,
economic and social development will suffer.
Any conceivable increase in energy efficiency will be offset by the growth in population and energy consumption per person in developing countries. Our own efforts in Europe to reduce C02 emissions will be overshadowed by the increase in developing countries.
The leading question is how to get into a sustainable growth path that reconciles the social and economic aspirations of the world's peoples for higher welfare while at the same time meeting concern for a cleaner environment and avoiding the dangers of global warming.
Table 3. The egological projections of world energy consumption
Fuel 1960 1990 2020 2050
Coal 1,4 2,3 (29) 3,0 (24) 4,0-5,0 (23-33)
Oil 1,0 2,8 (35) 3,8 (30) 3,0 (20)
N. gas 0,35 1,7 (21) 3,7 (29) 3,0 (20)
Nuclear e. 0,0 0,4 (5) 0,7 (6) 1,0-1,5 (7-10)
Hydro 0,15 0,5 (6) 0,8 (8) 1,0 (7)
New renew. 0,0 0,2 (3) 0,6 (4) 3,0-1,5 (20-10)
--------------------------------------------------------------------------------------------
Total 2,9 7,9 (100) 12,6 (100) 15,0 (100)
--------------------------------------------------------------------------------------------
|
Figure 3. Projections of world energy consumption
From a global perspective coal and other fossil fuel resources are still plentiful. Applying a less restrictive reserve concept,the physical availabilities of fossil energy resources are unlikely to emerge as the limiting factor during most of the 21st century.
Over the next century,the contribution
of fossil fuels to total energy supplies will largely depend on abilitv
to meet energy service demands in an environmentally acceptable way.Cleanness,
comfort and quality of service,rather than simple availability,will become
the benchmarks for coal and other fossil fuels.
COAL:
Global coal reserves are reasonably
well defined and ample as compared with oil and gas. Market prices for
coal (and gas) will continue to be related to the world price of crude
oil. Transport cost and provision of shipping facilities will become less
constraining on the use of coal internationally. However, even as "clean
coal" programs bear fruit,coal utilization will incresingly raise environmental
concerns. Notwithstanding, newer methods of mining and burning coal are
leading to enhanced safety and significantly reduced environmental impact.
Coal will further retreat from decentralised
uses in the industrial and commercial sectors. Electricity and district
heat production may remain a domain for coal as long as regional-scale
environmental disturbances can be avoided. Add-on scrubber and catalytic
conversion technologies have demonstrated that coal combustion processes
can be adequately cleaned up and that smog and sulphur dioxide emissions
can thus largely be avoided.
Perhaps with the exception of CO2 removal,
coal-fired
electricitv and cogeneration production capacity of the 21st century will
not rely on scrubbers and similar abatement technologies. Rather. stripping
pyrolitic sulphur and other impurities from high sulphur coals will occur
during the benefaction stage prior to combustion.
The low sulphur coal would then be burnt
in pressurised fluidised-bed combustors (PFC) or integrated coal-gasification
combined cycle (IGCC) systems.
Several other new coal conversion technologies also crack coal into its major elementar components, carbon and hydrogen,before any further processing occurs. As with IGCC plants, the synthesis gas can be used either for electricity and/or heat generation, hydrogen production, or for further chemical processing and synthesis of methane (CH4) or methanol (CH30H). Although substantially cleaner on a regional scale, these approaches do not reduce CO2 emissions beyond those resulting from the efficiency improvements.
Work is in progress to design and develop
processes which would produce separate streams of pure hydrocarbon and
CO2 or pure carbon.
Electrochemical processes including
gasification and/or hydrogenation with the activation energy, for the reaction
coming from electricity offer one possibility, for the pure CO2 approach.
These and similar processes are in an
early design stage and are currently far from technological feasibility.
Still, over the coming few decades such processes may well reach engineering
maturity and thus maintain a window for coal use throughout the 21st century.
OIL:
Oil will continue to be the dominant
energy resource used throughout the decade and well into the first half
of 21 century.Free markets, free trade, and market pricing are seen as
likely to work in accomplishing the matching of demand and supply -- most
of the time. Notwithstanding, there will be increased acceptance of managed
oil markets. Supply security, stability, and predictability of crude oil
prices will continue to be important to those nations which do not have
adequate indigenous energy resources, as well as to whose marginal cost
of production is higher than that in the Middle East. Japan is representative
of the former; the United States of the latter.
New technologies will continue to be
explored to assure availability at acceptable prices of liquid hydrocarbons
from such non-conventional sources as tar sands, very heavy oil, shales,
and ultimately coal. Since these sources greatly exceed those of conventional
crude oil and are located in quite different geographic locations, they
provide reasonable assurances that liquid hydrocarbons could be available
(at some price) for uses such as transport fuels well into the 21st century
and beyond.
From a global perspective, oil will
remain a leading energy source up to the middle of the 21st century. The
attractive properties of oil and its products are storability,transportability,
high energy density by volume and weight, as well as versatility of use.
Moveover, the relatively, low investments required in infrastructure and
end-use technology make it an attractive option for the growing energy
needs of many developing and newly industrialised countries.
The long-term future of oil in the industrialised
world will be highly dependent on a number of demand-side factors:
o the capacity of the automotive industry
to decrease automotive consumption further and to develop improved technical
solutions to meet local air qualitv standards;
o the ability of the oil industry to
develop cleaner fuels;
o the development and improvement of
new generations of car technologies based on electrochemical conversion
such as batteries and fuel cells, the latter fuelled by hydrogen. This
of course will require safe and economical hydrogen production lines and
infrastructures;
o consumer choices between old and new
transport arrangements and technologies.
The potential oil markets of the future
will increasingly be linked to the transport and chemical feedstock sectors.
In both sectors oil is difficult to replace in the medium term. Electric
transport will be improved along new lines: in the early stages battery
power will be important, but in the longer term hydrogen and fuel cells
could be developed.
Looking at the supply side, crude oil
is certainly a finite resource but not all of the world's reserves have
yet been located. In addition to 150 billion tonnes of proven reserves,
there is thought to be about the same amount in the uncertain or yet-to-be-found
categories. In the long term,operating experience and technology development
will allow more oil to be recovered than originally thought likely. Conventional
crude oil could last for at least 80 years even at current rates of consumption.
NATURAL GAS:
Gas resources are relatively plentiful,
as compared with current rate of consumption, on a worldwide basis. Natural
gas reserves are higly concentrated in the former Soviet Union and Iran.
Large natural gas reserves are available in the United States and Canada,
as is the related transportation and distribution infrastructure.On a global
basis, price, availability and the costs of transport, as well as supply
security, will be major influences on decisions of consumers remote from
sources of gas supply. Gas will increasingly be seen as the fossil fuel
of choice, especially when considering environmental impacts. This status
will be tested in the global market as demand and price increase.
The resource base of natural gas is
large. Advances in the geosciences over past decades have led to a better
understanding of the magnitude of natural gas resources. The greater depth
of most gas reserves requires different and more advanced drilling techniques
as compared with oil production. By the early 21st century these technologies
will have matured,and as the disassociation of gas from oil progresses,
productivity will increase so as to make the production of methane from
fields other than conventional oil domains a commercially viable undertaking.
Furthermore, gas has repeatedly been
found in unlikely places. This suggests significantly that gas is more
widely distributed geographically than was traditionally thought to be
the case.
Natural gas exists as both "free" natural
gas in reservoirs, and below ocean depths and permafrost as solid gas hydrates
(methane inside a cage of water molecules(CH4.6H20). Gas hydrates are the
largest potential source of natural gas but are normally excluded from
gas reserves. The largest reserves are in the Arctic regions of Russia,
Canada and the USA. Other deposits exist in the Gulf of Mexico, Black Sea,
Caspian Sea and Peru Trough. Estimates of the extent of the hydrates vary
enormously but the data suggests that they may amount to over ten times
the reserves of conventional natural gas.
No commercial processes currently exist
to exploit these reserves. Heating, depressurisation and adding an antifreezing
agent have all been considered. Gas hydrates are a fascinating subject
for scientists and technicians but, some suggest, are unlikely to be a
significant source of natural gas until well into the next century.
ELECTRIC ENERGY:
Total energy use has become decoupled
from economic growth in the developed countries. However, electricity use
remains quite closely coupled with GNP growth. Electricity is increasingly
the choice of energy in end-use, in both developed and developing nations.
The mix of primary energy resources used to produce electricity will continue
in a state of flux: oil with limited appeal; coal as an economcally preferred
fuel where available; natural gas being favored in some nations as more
economically and environmentally acceptable - subject to supply, price
and transport considerations.However,nuclear power will continue to play
a strong role with timing dependent on regional demand for electricity
and the related availability and cost of both natural gas and coal, as
well as hydro and other resources.The option of using nuclear,which will
not be limited by its resource basis,should be kept open. However, the
commitment to the further use of nuclear power is somewhat precarious in
most nations.
While there are large undeveloped hydroelectric
power resources in the world, they are generally not in areas with enough
demand for power to make development economic. The transmission of electric
power will remain reiatively costly, even with bulk DC transmission.Environmental
concerns about hydroelectric development and associated transmission lines
will grow.
HYDROGEN:
Hydrogen and electricity are likely
to play major roles in the longer term energy system. Together they can
meet most energy service requirements. Hydrogen and electricity are the
only carriers that can, together, meet all energy service requirements
and do not contain the carbon atom. In addition, both carriers are truly
renewable. Electricity, which may be viewed as an electrical charge separation,
returns to a neutral charge when it is used. Hydrogen - by analogy water
separation - returns to water when it is used.
lt can be anticipated over the period
to 2050 that among the most important end-use technologies, we will witness
the decline of the internal combustion engine and all other combustion
technologies which close their fuel cycle of carbon oxidation through the
atmosphere. The carriers hydrogen and electricity will drive the electrochemical
energy conversion devices,catalytic energy converters, electric motors
and heat pumps of the future.
The fundamental key for the hydrogen
and electricity tandem is that they are blind to their sources, i.e., they
can be produced from a variety of non-fossil and fossil sources. Today's
sources and the technology routes used for hydrogen production are still
extremely limited, but the range of future options is very large.In the
light of the unknown impacts on global cliniate of a continued accumulation
of CO2 in the atmosphere, this source flexibility makes the twin carriers
hydrogen and electricity the ideal energy policy insurance. Thus, there
is no need to embark early on irreversible investment or policy decisions
which may foreclose future options.
Transporting hydrogen over large distances
is in principle cheaper than electricity transmission.Hydrogen therefore
offers not only a storage option for photovoltaic electricity,which is
obviously limited in availability to daylight hours, but also provides
a link between large-scale remote photovoltaic sites where conditios may
favour production costs and the centres of energy use.Moreover, solar hydrogen
opens markets other than traditional electric energy services,such as the
transportation sector.
On the other hand, hydrogen is a relatively
dangerous substance:It is the lightest of all elements. It is colourless,
odourless, tasteless and non-toxic. The probability of combustion from
a random ignition source is greater for hydrogen leakage into a confined
space than it is for other industrial flammable gases or gasoline.Also
hydrogen penetration through leakage paths such as porous materials, cracked
weldings, damaged seals, etc.. is higher than for other fuels.
In summary, industry knows the necessity
of recognising the unique properties of hydrogen and following the safety
codes conscientiously. If hydrogen were to be used on a large scale and
distributed through comprehensive networks the overheads and perhaps even
the technological feasibility of dealing with the increased hazards could
become a limiting factor, at least for a time.
NEW AND RENEWABLE ENERGY RESOURCES:
New and renewable energy sources are
generally defined to include hydropower,solar energy,wind,wave energy,biomass,geothermal
and oxygenated fuels(alcohols,etc.) and hydrogen.Except for hydroelectric
power, these are not likely to play a significant role in the decade ahead.
The principal issue for most alternate sources is that of economics, except
in unique applications.In those nations where such sources are appropriately
and economically competitive with other options, they will contribute to
energy supply.Many nations will continue to use biomass(wood,etc.) and
biogas to support their developing economies,supplementing them more conventional
energy supply in the long run.However,rapid depletion of fuel wood in many
regions is expected to create earlier demand for rural electrification.
While changing technologies and costs
offer some favorable prospects,don't count on breakthroughs in alternative
energy to eliminate the need for dealing broadly with the environmental
and safety issues raised by the current conventional sources of energy-for
a long time to come.
In the longer term,all renewables are
good
candidates for cost cuts by organisational learning which is particularly
inherent in small plants. The leading principle in terms of size and local
conditions should be "appropriate is best".
Renewable energy sources, combined with
a system of new technologies, can contribute to a considerable extent to
energy requirements in the time horizon beyond 2020. They can also contribute
to an energy future which will reconcile the need for economic growth with
environental concerns and energy security,without a significant increase
in costs - as compared with conventional fuels - and moreover without fundamental
technological breakthroughs.
Alcohol,ethylene, or methanol production
biomass in regions with surplus arable land or forestry may contribute
to the supply of transportation fuels. But with world population growing
and the enhanced use of fertilizers being under critical review,the diversion
of productive agricultural land to energy purposes loses attractiveness.Also,
growing plants require large amounts of water. Water itself is becoming
a scarce resource and thus could present another limiting factor to energy
-designated biomass production.
Direct solar radiation energy is often
considered as the ultimate source for electricity and subsequent hydrogen
production. Technologies harvesting solar energy directly fall into two
categories: central and decentralised.
Central or solal thermal electricity
generating technologies are based on reflective solar collectors that track
the sun and concentrate the heat into a heat exchange fluid. The most promising
concepts to date operate as hybrid systems, i.e.. in combination with a
fossil back-up system to augment the solar heat as needed.
Decentralised solar technologies include
solar panels for low temperature heat generation, usually for space heating
or hot water purposes. Because solar heating systems in moderate climate
areas still depend on a conventional back-up system or extensive heat storage
systems,their future role will depend on adequate passive and active building
designs and insulation standards.
Probably the most important solar energy
technology ,the application of which is independent of scale,is photovoltaic
electricity generation. Photovoltaic cells generate electricity with no
pollution, noise or moving parts.Because there is no working fluid involved
they are independent of water availability and thus ideal to operate in
remote suny and arid locations with minimum maintenance.
lt is premature to project which photovoltaic
technology will eventually dominate. But over a time horizon of fify or
more years, it seems highly likely that photovoltaics will have positioned
themselves as a viable electricity production option. For practical applications
under typical conditions efficiencies of 20 % to 25 % are expected to be
reached in the not so distant future. There will be marked regional variations
in scale and application.
Solar electricity, combined with its
storability as hydrogen,could thus overcome its present disadvantages and
be capable of playing an important role in overall energy supply world-wide.
Hydraulic and wind sources are unevenly
distributed geographically, which limits hydrogen and electricity production
from these sources to regions with sufficient hvdraulic and wind availability.
Since wind-generated electricity represents an intermittent source of energy,.
hydrogen conversion may help flatten the discontinuities and thus help
improve the overall performance of wind converters. One should note, though,
that the ever-increasing physical dimensions and accompanying disturbance
of hydro power and wind energy projects can cause local environmental concerns
to some degree.
Today, among all new and renewable sources
of energy, geothermal energy is the most important producer of thermal
and electric energy following hydroenergy and biomass as the "classic"
renewable sources. Continuous availablity of geothermal sources not depending
on weather conditions, with reliable supply and possible storage represent
a great advantage of geothermal energy in comparison with other NRSE.
An enthusiastic wiew has been expressed
in a recent UN report which suggests that using technology already on the
market or at the advanced engineering testing stage,by the middle of the
next century renewable sources (including solar, wind, hydro and biomass)
could account for 60 % of the world's electricity market and 40 % of the
market for fuels used directly.The report argues that this could be achieved
competitively at energy prices lower than are expected in conventional
price forecasts, with the result that C02 emissions could be reduced 25%
relative to 1985 levels,while the world economy might be eight times as
large as at present.In addition to the expected benefits for reducing air
pollution and global warming, the authors argue that a "renewables" scenario
would:
o improve energy security by increasing
fuel supply diversity;
o match social and economic development
aspirations in rural areas of the world through the use particularly of
biomass;
o the opportunities for growing biomass
for energy on degraded land can of themselves provide the incentives
and the financing needed to restore such lands.
In summary, if the relative position
of technologies in their respective technology life cycles is taken into
account, they offer considerable promise for future performance improvements.In
particular, this means that present achievements at the laboratory level
can be transferred to the field.
CONCLUSIONS:
We can make a number of fundamental conclusions. Let me list the most important ones:
- Energy subsidies must be phased out in order for all consumers to understand the implications of the real costs of energy.It was recognised that in many regions this process will take many years. The corollary, if no such action is taken, is that governements, if they subsidise energy, will gradually reduce their financial ability to supply commercial energy, with the subsequent risks of economic regression and increased environmental degradation.It must be advocated the adoption of full cost pricing in order to achieve ultimate sustainability.
- Extending its reasoning further, the interesting point is that many of the facts about the energy sector which today are believed by end use consumers are wrong - and they are wrong because the signals about supply availability, costs and prices, the existing degree of environmental degradation and the state of current institutions which handle such matters, are themselves inconsistent and confused. Institutional changes in a number of key areas, of which finance is one, were strongly advocated. The world will require some US$ 30 trillion over the next 25 years (in 1992 money) with which to develop energy projects. This equates to 50 % more than the entire 1990 world GDP. If such finance is to become available, many radical changes need to be implemented to secure it, particularly with regard to mobilising local capital markets.
- And finally,improvements to be made
to the transparency and general understanding of energy,and what its "sustainable
supply and use" mean. Common action to be taken to increase access to commercial
energy for the deprived. This is a basic moral responsibility for all countries
and nations.
- Status of energy potentials,production and consumption in Yugoslavia.
- Trends of development of energy in
Yugoslavia up to 2020.
Owing to its socio-political and economic
development after Second World War Yugoslavia grew from an underdeveloped
country into a medium-industrialised country.The dynamic economic growth
required an equally dynamic development of energy production and use.Dynamic
growth of our country requires ever larger quantities of energy to meet
predominantly,the needs of industrial,transportation and households consumption.
The main characteristics of the Yugoslav energetics in year 1990,before the disintegration of SFRY and the beginning of the international blockade and economic sanctions,are:
- Very intensive development of production of secondary energy , especially the highly intensified production of electric power in the thermal power stations(more than 80 % of coal consumption),also intensified production of oil products from imported and domestic crude oil and very fast development of district heating sistems in the towns;
- Inadequate reaction on "energy crisis" in the 70's by very high rate of consumption,without supstitution imported fuels;
- The primary energy consumption totalled
about 18 Mtoe with the import dependence of 40 %.The per capita consumption
rate of primary energy in Yugoslavia,1,8 toe/cap,was among the lowest in
Europe,but the aggregate energy intensity rate in Yugoslavia was among
the highest ones because of a relatively low social product;
Figure 5. Total primary energy consumption
Figure 6. Final energy consumption
- Very high dependence of imported energy,covering up to 40 % of the total energy consumption,especially in crude oil and natural gas;
- Very intensive investments in energy capacities.Only in electric power industry in the period of 1975...1990 are invested 15 billion USD.
- There were frequent changes in control
policies and mechanisms of energy prices.
Besides that, in the period of sanctions
and economic blockade,in addition to agriculture, the energetics of Yugoslavia
behaved the largest load in maintenance of our economy and society.Energetics,as
a main infrastructure branch,in previous SFRJ has been optimised on the
level of state and before the economic sanctions,the consequences of disintegration
first exerted influences on energy industry.In 1991 has stoped to work
Yugoslav oil pipeline Krk-Pancevo and interrupted the network of the electric
power suply system of Yugoslavia and the connection with the West European
UCPTE interconnection.The second blow on Yugoslav energetics has been on
May 1992 with economic blockade.
The shortage of imported fuels and the
impacts of the international blockade contributed that domestic production
of energy have been obliged to preserve high level of production (practically
only of yugoslav industrial branches) to supply industry and households.In
that period the energy supply sector of Yugoslavia was suffering very much
resulting in the following:reduction and discontinuation of prospecting
for energy raw materials,difficult economic position resulting from a non-economic
prices of energy sources, deteriorated reliability od production fiacilities
and supply to consumers, discontinued investment in energy sector,personel
losses,etc.The consequences of sanctions will have very high price for
the energy industry and will be felt for many years to come and to be in
the position it have been in the beginning of 90's.
The sanctions exerted influeces on change
of the structure of final energy consumption.In the period of economic
blockade,because of high imoport dependence of oil and gas industry (about
4/5 of quantity),and the structure of energy consumption in our country
has been changed (Table 1) :
Table 1. The level and structure final
energy consumption in Yugoslavia
| Sort |
|
|
95/90 |
||
|
|
|
|
|
||
| solid fuel |
|
|
|
|
|
| oil products |
|
|
|
|
|
| natural gas |
|
|
|
|
|
| electric power |
|
|
|
|
|
| total | 11809 | 100,0 | 6496 | 100,0 |
|
In this table is obvious that in 1990 the participation of oil and natural gas in the structure of energy final consumption was 64,3 %,, the same as in western countries.But after the economic blockade it have been 45,7 % or very low percent.The oil and natural gas have been supstutute by domestic source,electric power,very cheap energy source, without any possibility to improve energy efficiency or to use other energy source.
In the period of 1995 and 1996,in the
time of the influence of economic blockade,was finished the "Strategy
of Development of the Energetics in the FR of Yugoslavia until the Year
2020 with a Vision of the Period to 2050" .The STRATEGY was prepared
for the purpose of showing,on the basis of an appraisal of the long-term
needs and a systemation of all resources,the direction to be taken towards
a lasting harmonious and tenable development of the Yugoslav energetics.
Although,after the end of economic blockade
and sanctions of UN Security Council ,the state of energetics became better,it
is very complex too.In the past two years became evident that the STRATEGY
and also the Middle-term plans of Public Energy Entreprises didn't realized
.Today the economic situation in the field of energy is very heavy, the
prices of energy is not high enough to cover the cost of normal operation.Also
the development of economy and industry is verry slow.
The development in 90's and present
state of energetics of Yugoslavia, before the war and bombing, must be
defined by some main characteristics:
1.The structure of domestic energy resources
is a uniform one to a large extent.The energy resources of Yugoslavia are
mostly in the lignite reserve(about 80 % og geological reserves) and much
less in hydroenergy,cryde oil,gas,uranium ,oil shale,etc.The geological
reserves are more than 4 billion tonnes oil equivalent (toe=42 GJ), in
which the share of the coal is 85 %,of crude oil and natural gas 1,5 %,oil
shales 4,8 %,hydropower 5,7 % and uranium 2,7 %.More unpleasant situation
is in proven reserves, where the share of coal is 99 %(lignite more than
92 %) .But the abundance in lignite reserve and the fact that 90 % of reserves
is located in four big basins (Kosovo,Kolubara,Kostolac,Metohija) makes
it possible to maintain the country's exixting energy self-sufficiency
degree and possibly increase it.According to what is known at present,the
total usable hydroenergy amounts to about 27 000 GWh,of which only about
12 000 GWh have been activated so far.The big difference between estimated
geological and proven reserves of crude oil and natural gas shows that
they haven't been prospected for enough,particularly in Republic of Montenegro.With
the development of commercial technologies,greater importance could be
attached in the future also to the oil shale and uranium reserves.The potentials
of the new and renewable energy sources are considerable and important
for FR Yugoslavia because there are favorable conditions for their use
taking into account the availability of the resources,but it is still uneconomically
in many fields od aplication.
2.The production of coal (Table 2) is
enough for the prodction of electric power in thermal power stations,but
it is evident the problem of shortage of the high-quality coals for industrial
and general purposes and all quantities of coke.The existing reserves will
not be a limiting factor for a bigger production.The consumption will be
,more than 80 %,in thermal power stations for producing electric energy.
The production of crude oil and natural gas covered just a little more
than 20 % of total needs .The maintenance of the existing level of self-sufficiency
and its possible improvements call for an intensification of exploration
in the country and concession-based linking on the basis of long-term arrangements
in the country and abroad,which could cut the direct import dependence.
Table 2.The production of primary energy
,000 toe
| Sort |
|
|
|
|
|
|
|
|
|
|
||||||
| Hydropower |
814
|
1053
|
1250
|
1098
|
980
|
1,29
|
1,20
|
| Coal |
8329
|
7515
|
7200
|
8007
|
8068
|
0,90
|
0,97
|
| Oil |
1074
|
1067
|
1027
|
992
|
992
|
0,99
|
0,92
|
| Natural gas |
564
|
739
|
556
|
592
|
598
|
1,31
|
1,06
|
| Total |
10781
|
10374
|
10033
|
10689
|
10638
|
0,96
|
0,99
|
* tone oil equivalent (toe = 42 GJ)
** plan
3.The capacity of the facilities for
the generation of electric power is about 10 000 MW,of which about 6000
MW is accounted for by the coal-fired thermal power stations,with the possibility
to produce about 40000 GWh per year.In the table 3 is shown the data about
the production of electric power(neto) in the period 1990..1998.The available
primary energy potentials are such that it will be possible to expand the
production of electric power also in decades to come on the basis of the
country's own resources-lignite and hydropower.
Table 3.The production of electric power
in Yugoslavia, GWh
| Sort |
|
|
|
|
|
|
|
|
|
|
||||||
| Hydropower plant |
9372
|
12200
|
14540
|
12762
|
11394
|
1,30
|
1,26
|
| Therm.power plant |
28910
|
22282
|
20718
|
24664
|
25789
|
0,77
|
0,89
|
| Total |
38282
|
34482
|
35258
|
37426
|
37183
|
0,90
|
0,97
|
| EPS |
35268
|
3306
|
|
35246
|
34702
|
0,94
|
0,98
|
| EPCG |
3014
|
1476
|
2984
|
2180
|
2481
|
0,49
|
0,82
|
*plan
The capacity of the facilities for the
primary processing of crude oil is about 7,8 milion tonnes and ,with the
modernisation,are enough for the future.The capacity of the facilities
for the production of dried lignite is about 2 million tonnes.
4.The basic network of the electric
power supply system of Yugoslavia is linked with the systems of the countries
in Yugoslavia's neighbourhood by 400 kV lines.The powerful electrical transmission
network enable quite reliable and economic operation of the electric power
system in Yugoslavia globally having created opportunities for more intense
usage of the domestic sources of energy.The gas pipe line system connects
all the gas fields in Vojvodina with the consumers. It also makes possible
the imports of gas from Russia through Hungary and transit of gas to the
former Yugoslav Republic of Bosnia and Herzegovina. The total length of
the system is 1669 km, of which 624 km of supply lines and 627 km regional
lines. The capacity is 3.8 billion cu.m. in Vojvodina and 1.715 billion
cu.m. in central Serbia.
5.The primary consumption of energy in the period after the end of economic blockade and sanctions of UN Security Council had very intensive growth (fig.7), that in this year is about 90 % of the consumption in 1990.This is not in harmony with the projections in the STRATEGY /1/ because is much more than the level of consumption in medium variant and close to optimistic variant.
Figure 7. The consumption of primary energy
6.In the same period the structural changes in the final consumption of energy have been evident.Under economic blockade and sanctions of UN Security Council,without possibilities to import high quality coal,crude oil and natural gas and in period very low prices of energy sources ,the industry and households have used much more the domestic sources of energy,especially electric power(figure 8).
Figure 8. The consumption of electric power
But after the period of economic blockade,
the using of energy in Yugoslavia didn't changed.In households used electric
power for heating purposes as much as possible,and in the same time was
very high import of crude oil and natural gas and verry high final consumption
of energy (Table 4).It isn't in the corelation with the projections in
the STRATEGY/1/.
Tabela 4. Growth of final consumption of energy in Yugoslavia
Indeks 1990 = 100
| Sort/Year |
|
|
|
|
|
| Electric power |
|
|
|
|
|
| Oil products |
|
|
|
|
|
| Naural gas |
|
|
|
|
|
The projections of the future needs
in energy have been prepared by using a multi modular model.The model is
based on an energy-technological aproach,in line with the volume of physical
activities and energy-economic or energy-technological indicators and potentials
of energy saving.
The total final consumption of energy(fig.9) will reach the 1990 level (12 Mtoe) around the year 2005 and by 2020 it will reach 18 Mtoe,which is by 50 % more thab in 1990.In 2020 the energy intensity,measured on the basis of final consumption will be by 18 % lower than in 1990,as a cumulative result of risen efficiency and restructuring of the national economy.
Figure 9. Final energy consumption by sectors
The chief long-term movements in the
structure of final energy consumption (fig.9.) should go towards : a decrease
in the share of liquid fuels,an increase in the shared of gas,a decrease
in the shared of solid fuels,a gradual decrease in the currently very high
share of electricity and gradual introduction of new and renewable sources
of energy.
According to the projected final consumption and its structure,the total consumption of primary energy will be about 26,6 Mtoe in 2020,which is by about 46% more than in 1990 (Table 5).
The per capita energy consumption rate
will be about 2,3 toe in 2020,which is about 75 % of the average consumption
in developed countries in 1990.The share of coal will still prevail in
the structure of the total primary energy production,and the share of gas
will increase significantly (fig.10).Together with the concession-based
production,the import dependence would be about 42 %.
Figure 10. Total primary
energy consumption
DEVELOPMENT OF ENERGY SUPPLY SECTORS
Solid fuels
The estimated consumption in the period ending in 2020(fig.11) will call for the development of facilities for an output of about 65 millions tonnes a year,for which the existing reserves will not be a limiting factor.This consumption will be ,more than 80 %,in thermal power stations for producing electric energy.
Figure 11. Solid fuels consumption
Oil
It has estimated that in 2020 the consumption of liquid fuels will be about 7,5 milion tonnes(fig.12) or about 660 kg per capita( 50 % of the average of OECD ).This is about the existing capacity of oil refineries.The reserves of oil in country are low.The maintenance of the existing level of self-sufficiency and its possible improvements call for an intensification of exploration in the country and concession-based linking on the basis of long-term arrangements in the country and abroad,which could cut the direct import dependence (fig.12)
Figure 12. Liquid fuels consumption
Natural gas
An increase in the share of natural gas in covering the needs in energy was set earlier as a strategic options in the development of the energy supply industry.The consumption of gas (fig.13) should increase at the highest rate as the result of substitution of other fuels and increased demand,and by 2020,it should reach about 6,2 billion m3 and cover the total energy demand by 20 %.Most of that consumption will be imported.The future domestic production will be afected by the naturally diminishing production in the gas fields currently in use.
Figure 13. Natural gas consumption
Electric power
According to the projections,the 2020
output in electric power will be about 47 TWh while the required output,including
transmission and distribution loses will be about 54 TWh.In terms of specific
electric consumption,Yugoslavia is much closer to developed countries than
in the case of other energy sources.The available primary energy potentials
are such that it will be possible to expand the production of electric
power also in decades to come on the basis of the country's own resources-lignite
and hydropower.It woul be necessary to strive for a greater application
of new and ecologically better coal utilisation technology,such as fluidised
bed combustion and combinaed cycles.The relative abundance in lignite reserves
makes it possible for a part of such reserves to serve as the basis for
the construction and operation of thermal power stations together with
foreign partners.
New and renewable energy sources
Most of the NRES are stil in the phase of development and industrial research.The chief objective is their greater utilisation for autonomous and local purposes,for the needs of the "small scale power industrie",to meet the demand in low temperature heat in the first place.
Their importance will be increased in
FR Yugoslavia too along with the development of economical technologies
for their use which is expected in the next century when high-temperature
energy needs and electric energy production are concerned.
CONCLUSIONS
The transition to a sustainable energy
system requires more than just marginal adjustments or the replacement
of certain energy sources. The transition must proceed from the level of
energy services and end-use technologies.The long-term policy target for
energy system development must be to encourage the transition to energy
systems in which the fluxes to and from the system are coherent with nature's
fluxes and do not perturb nature's equilibria. Only then will it be possible
to provide for economic growth without environmental costs undermining
the gains.
THE GEOTHERMAL ENERGY IN FR OF YUGOSLAVIA
New and renewable sources of energy
(NRSE) are specially important for FR of Yugoslavia because there are favorable
conditions for their use taking into account the availability of the resources.
Even though their research has already started twenty years ago, the results
obtained until now demonstrate clearly that although many optimistic expectations
were not accomplished, owing to favorable local conditions in Yugoslavia,
the NRSE have already been used to meet various low-temperature energy
needs (particularly solar and geothermal energy). But with the exception
of hydroenergy and the most frequent conventional renewable resources (biomass
and agricultural wastes), it is not possible to speak about a real energy
balance of those resources because their usage is verry small.
New and renewable sources of energy
will have more importance in the next century because they will enable
fulfillment of energy needs without considerable ecological problems; they
will also enable a greater substitution of conventional fuels, particularly
oil and gas. It is of a special interest for our country because as already
stated, we have considerable potentials of NRSE and we do not have sufficient
high quality sources of energy.
It is generally known that Yugoslavia,
especially Serbia, lies in the zone with favourable geothermal conditions
. This zone starts from Hungary on the North , expanding to the areas of
Greece and Turkey and further up to the East. But Yugoslavia is one of
the few European countries in which systematical measurements of the essential
geothermal parameter- the terrestrial heat flow, have not been carried
out. Thus, for the purpose of evaluating the geothermal energy potentials
in Yugoslavia and, also, in Serbia, the estimates of these values are given
on the basis of general geological and geotectonic data, minor measurements,
results obtained by hydrogeological explorations and the results of geothermal
investigations in neighbouring countries. Generally speaking, the explorations
rates are still very low and further geological, hydrogeological and geophysical
explorations, including deep well drilling, will be necessary.
The principal indications of a possible
geothermal energy source are temperature and heat flux which depend on
the origin and distribution of terrestrial heat sources in the earth's
crust. According to our present knowledge, the most probable causes of
the positive terrestrial heat flux values in Yugoslavia are the heat emanating
from young neogenic igneous intrusions, heat conducted from the lower depths
of Earth and heat generated by the radioaktive elements decaying in acid
igneous intrusions. Studies of the thickness of the Earth's crust by deep
seismic methods show that in Yugoslavia the crust is from 25 to 40 km thick.
Acordingly, it can be considered that the average values of regional heat
flow due to heat conduction from the Moho Discontinuity will amount to
about 80-100 mWm-2 , much more that the values for Europe (Europe cca 60
mWm-2). Also, some parts of the Earth's crust in the territory of Serbia
underwent intensive magmatic activation in the Tertiary, and particularly
in the Neogene, and numerous granitic rock intrusions were formed. According
to the results obtained so far the area of Tertiary magmatism and particularly
of Neogene magmatic activation, appears to be the most promising for the
geothermal energy use in Yugoslavia, In this areas heat flow values can
be several times higher the average (up to 200 mWm-2 ). It is realistic
to assume that the terrestrial conductive heat flux averages, are no less
than 100 mWm-2 ,in 30% of Serbia's territory and that these regions thus
qualify for thorough exploration conducive to future economical use of
their geothermal potential. The conductive heat, i.e. energy reaching the
surface, totals 50.10 15 J. Temperature measurements are also still rare
even during geophysical logging. That is why it is possible to make just
an estimate of the potential and even that only individual areas rather
than for Yugoslavia as a whole.
The relatively low level of investigation
of Yugoslavia's territory, notwithstanding the results of various geological,
geophysical and hydrogeological investigations, initial geothermal investigations
and data available on natural thermal springs, make it possible to assess
Yugoslavia's geothermal energy . It is confirmed by the fact that in our
country there are numerous spas and natural springs with water temperatures
over 300 K (fig.1.).The hottest are the thermal springs at Vranjska spa
: with 94 oC these are also the hottest natural springs in Europe.
Systematic research in Vojvodina started
in 1969 when the first hydrothermal hole was bored - Subotica S-l, and
to date, 68 holes were bored with the average depth of 800 to 1200 m. Besides,
42 negative oil-gas holes were tested to ascertain possibilities of their
utilization as geothermal holes. Out of 110 tested hydrothermal, oil and
gas holes, only 24 are used today; only 11 holes are used for heating.
Based on the research activities to date, it has been concluded that a
larger part of Vojvodina is very promising for obtaining geothermal waters
up to the temperature level of about 363 K.
In the previous period, in the central
part of Serbia, mineral and thermal waters were registered at 241 localities
- over 90 % were natural and only 8,8 % were discovered by boring. 1080
natural and "artificial" springs of thermal waters were registered in these
localities. Out of 241 localities, hydrothermal research was carried out
on 128; on 89 localities exploitation boring was done. From 1965 to 1992
the total of more than 300 hydrothermal holes was bored. Besides, thermal
waters were registered in 40 oil-geological holes and 37 other purpose
bored holes. All springs with temperatures over 20 oC yield on the average
about 1800 lit/sec,i,e. over 155.000 m 3/day whereas the yield of springs
with water over 30 oC exceeds 60,000 m3 /day: this means that the geothermal
energy surfacing from those springs totals about 3.10 15 J per anum.
The temperature, physical and chemical
composition, yield, place and flow of the above thermal and thermomineral
springs, the geological composition, hydrogeological and general geothermal
conditions of the cities and their environs show that there are major deposits
and sources of geothermal energy. This is the reason that until a few years
ago there were hydrogeological and geothermal investigations in the vicinity
of hydrogeothermal phenomena, aimed at increasing the capacity and temperature
of the existing natural hot springs. These investigations have been in
Vranjska, Ribarska, Lukovska, Prolom, Mataru{ka and Selters spas where
many wells were drilled. Also hydrogeological investigations were conducted
in Vrnja~ka, Sijerinska, Kur{umlijska, Ni{ka and other spas, with positive
results for the capacity and temperature. By virtue of the effektive financing
system once this objektive was successfully achieved, the investigations
would be discontinued and possibly resumed only when the relevant spa's
water consumption would reach the spring's operational capacity. This means
that no modern hydrogeothermal system in Yugoslavia has yet been studied
in its entirety and that exploratory drills seldom went below 1000 m.
It has been mentioned that only lately
we have become witness to some attempts to explore sites without visible
natural manifestations, where geothermal indications emerge from other
kinds of research. These investigations were in the vicinity of Prokuplje,
Lazarevac, Ljig,Beograd and the best results are achived in the region
of Macva. Hydrogeothermal investigation in Macva began in 1981, and in
the past years, although not completed, revealed large low temperature
hydrogeothermal resources of European , rather than national, importance.Neogene
sediments in Maeva have a thickness of 200-1500 metres, over Triassic karstified
limestiones and dolomites.Thermal waters are found by drilling in six localities,
so far from one to the other. The most signifikant occurrence was that
at Bogati}: discharge from the small-bore well was 37,5 l/s and water temperature
at the well head 75 oC. The highest expected temperature in the reservoir
is about 100 oC. Geothermal energy accumulated in thermal water in this
aquifer is estimated at 3.2.10 15 kJ.Natural conditions in Macva are favourable
for an intensive exploitation of geothermal energy. Also, the quality of
all water discharges was close to that of drinking water. While preliminary,
the given hydrogeothermal data suggest a very large geothermal resource
in Macva as an excellent source of economic geothermal energy production.
Based upon data obtained until now it
may be estimated that there are very promising regions in this part of
the country such as: parts of Panonian basin, Ma~va, Posavina, Tamnava
region, Pomoravlje and Podunavlje , the regions of Vranje and Toplice,
and many others. If the use of existing natural springs and holes in Serbia
up to 300 K is analyzed, which today is technically and economically justified,
the following values are obtained:
Table 1 - Geothermal resources in Serbia
-----------------------------------------------------------------------------------------------
Region Possible production Thermal power Energy saving
-----------------------------------------------------------------------------------------------
Central Serbia 688 90 20.000-40.000
Vojvodina 741 85 18.000-36.000
Kosmet 229 14 3.000-6.000
------------------------------------------------------------------------------------------------
TOTAL: 1658 189 41.000-82.000
-----------------------------------------------------------------------------------------------
Research of the geothermal energy for
its faster development in Serbia is a multidisciplinary activity and needs
huge financial investments. For this reason rational use of such financial
sources is iniportant for each phase of the exploration. First, we have
to start with measurements of the heat flow, as a background for further
investigations. Where we have an indication of geothermal anomalies, detailed
geological, hydrogeological and geophysical measurements have to be provided
before exploratorry driling. And also,the explorations which started in
Macva and other sites should be continued for determination of geothermal
energy resources.
Geothermal energy has been known for thousands of years now, although it has been used for balneological purposes. Today geothermal energy is basically used to supply heat energy, generate electric energy and for balneological and recreational purposes.
The investigations conducted so far
have not yet justified the expectations regarding high thermal fluid temperatures
alowing economical generation of electric energy, but showed that they
were quite adequate for the supply of heat (to heat houses and dwellings,
hot water, green-houses, hot-houses, stables and fishponds, air conditioning,
etc), i.e. they could meet the low temperature requirements in the major
part of Serbia.
In our country, thermal energy as the form of the geothermal energy is today applied at the most in recreation centers; in most of spas in our country the thermal energy is used for heating, preparation of hot running and basin water by which the electric energy and conventional fuels are considerably substituted.At present geothermal energy sources, chiefly, are exploited in 42 places in Serbia; of them, 4 served to built health and tourist resorts which now enjoy international prestige; 16 sites have been turned into modern regional health and recreational centres, and the remaining 16 are thermal springs used by the local population in a rather primitive way. Other natural or man-made hot springs are not exploited yet,although this would represent a major social advantage. In addition to its health and recreational application the water from thermal springs is only seldom used to supply consumers, far below their overall heat potential. For the heating purposes geothermal energy is used in many spas (Prigrevica,Melenci,Vranjska, Sijerinska,Jo{ani~ka, Ribarska, Ni{ka,Kur{umlijska,etc), but in much more spas and sites, where geothermal energy is occured, the projects for utilization are under way.
In other words, of the total amount
of water currently flowing from hot springs, about 15 % are put to properly
organized modern use, mostly in balneology, although the geothermal energy
possibilities are in reality much greater. But the problem of larger utilisation
of geothermal energy is the capital requirement. This cost is more than
most local organizations could possibly finance out of their own revenue
and profits. Because of that for further intensive utilization of geothermal
energy, some system solutions, especially concerning the financial problems,
are indispensable.
Today overheated, dry-saturated and
wet vapors and hot thermal waters are used for production of electric energy.
For us, particularly interesting are thermal models of using hot thermal
water for production of electric energy through binary cycle as until now
we do not have natural thermal springs of temperature over 400 K.
Although in Serbia the utilization of
geothermal energy is not yet practiced on a large scale, scientific research
institutes and faculties have developed many techmological schemes for
the utilization of geothermal energy for certain sectors of consumption
(agriculture, households, balneology and recreation, etc,). Many original
projects for the use of geothermal energy with various physical and chemical
properties of thermal waters have been elaborated, and the construction
of pilot plants to be used in agriculture, district heating and balneary
and recreation needs, are initiated. Special attention is paid to the geothermal
installations with heat pumps, because, when balancing the useful potential,
diferent values are obtained depending on whether the heat pumps are used
or not. Application of thermal pumps and use of low-temperature thermal
waters for heating, hot water and air-conditioning would contribute to
a greater use of geothermal energy; important experience has already been
obtained in our country with relation to the above use.
Having in mind importance of geothermal
energy in Yugoslavia intensive R/D work has been completed over the past
years and represents a good base for faster utilization of geothermal energy.
The application of geothermal energy in Yugoslavia can grow faster only
if low temperature requirements are satisfied to a greater extent. At present,
this would be technically and economically justified. Nonetheless, if such
plans are to become operational, it is necessary not only to find financial
resources which are always lacking, but also to mobilize and organize the
society towards this goal. Relevant agencies should adopt regulations bearing
on all matters concerning investigation, exploitation and use of the geothermal
energy including estimates of reserves, resources and their potential.
Prospecting for geothermal energy is a high-risk activity, much more so
than the investigation of other energy fuels and requires larger funds.To
mobilize the society for broader geothermal energy utilization, it is necessary
to exploit the already investigated geothermal springs without delay, especially
the region of Ma~va, and incorporate them in Yugoslavia's energy balance
and thus substitute conventional fuels.
Previous results of research and use
of geothermal energy contributed to its greater application within the
bigger part of our country. Taking into account that only a smaller part
of the available geothermal capacities is used today (in Vojvodina only
about 9 %, and similar in the central part of Serbia) the realistic estimates
are that if the available capacities are used, it will be possible to substitute
oil from 80.000 to 120.000 tons per year, already around the year 2005.
All the more so because many towns have favorable local conditions for
centralized use of geothermal energy and the most promising geothermal
sources are located in the agricultural regions (Vojvodina, Ma~va, Podunavlje,
Pomoravlje, Stig, etc.) where it is possible to construct greenhouses,
hot flower beds, or fish ponds.
Prof. dr Nenad Djajic
Born at Po`ega 31.07.1941; matriculated
in Belgrade 1960; graduated from the Mechanical Engineering Faculty, Department
of Thermal Engineering in 1965; Master's degree at Faculty for Applied
Chemistry and Metallurgy, Department of Chemical Engineering in 1974;Ph.D.of
technical science-Energy Management at the Faculty of Mining and Geology,all
in Belgrade,in 1976.After graduation, worked and headed on Department of
centralized heat and gas supply at the Mining Institute in Belgrade. From
1970, teaching "Thermodynamics" and "Heat Engines and Energy Plants" at
the Faculty of Mining and Geology as the Assistant, Assistant Professor
(1976). Associate Profesor (1982) and Full Professor (1988). From 1976,
Head of Centre for Energy, Faculty of Mining and Geology. Participated
and headed work on more than 150 studies and projects related to energy
management, new and renewable sources of energy, oil and gas supply,rational
use of energy, thermal engineering, centralized heat and gas supply and
ecology. Published more than 355 papers in journals, proceedings and symposias
(55 submitted to international meetings and journals ) autonomously or
as a co-author.Author of three University books:"Heat Engines" ,"The Machines
and Equipment for Drilling and Oil Production" and "Energy Sources and
Plants"and two monographies "The Measure and Regulation of Natural Gas"
and "The Production and Utilization of Geothermal Energy".Was present at
the most of the World Energy Conferences, Oil and Gas Congresses.Has been
in U.S.A., Canada, Poland, France, Great Britain, Germany, Austria, USSR
and Hungary at specializations and study visits.
Present: Full University Professor,Head
of Mechanical Department on Faculty of Mining and Geology,Belgrade;the
full member of Yugoslav Academy of Engineering; the member of Energy Board
of the Serbian Academy of Science and Art;the deputy secretary of Technical
Depertment of the Serbian Society of Science;the Vice Chairman of the Yugoslav
National Committee of the World Energy Council;the member of Federal Commission
for Strategy of Energy FRY; the Chairman of Union of Mechanical and Electrical
Engineers of Serbia.
Former: the member of the Executive
Council and Chairman of Energy Board of the City of Belgrade; the member
of the Committee for Energy and Industry of the Republic of Serbia;the
member of Republic Council for Rational Use of Energy;the member of Republic
Board for Energy Crisis;the member of the Scientific Council of Petroleum
Engineering Society of the Yugoslav Academy of Science and Art;the member
of the Federal Commission for New and Renewable sources of Energy and Federal
Council for Ecology; the member of Commission of WEC for "New Energy Perspectives
2000-2020", the member of the Rural Networks FAO; the Secretary General
of the Yugoslav National Committee of the WEC; the Chairman of the Serbian
Society for Solar Energy.