![]() | The Global Greenhouse Regime. Who Pays? (UNU, 1993, 382 p.) |
![]() | ![]() | Part III National greenhouse gas reduction cost curves |
![]() | ![]() | 10 Abatement of carbon dioxide emissions in Brazil |
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Energy sector use and transformation
Electricity generation
Electricity generation in Brazil is
dominated by hydropower (94 per cent). As already noted, we assume that
hydropower generates zero net CO2 emissions. We expect that this
share will fall by 2000. In the official SNE scenarios, the share falls from 94
to 85-88 per cent (ELETROBRAS 1990). Here we assume a moderate shift to thermal
generation such that hydropower falls to 90 per cent of total generation by the
year 2000. By then, 20 per cent of newly available generating capacity coming
on-line would be thermal (of which 10 per cent would be coal-fired; 40 per cent
would be natural-gas-fired; 30 per cent would be fuel-oil- and refinery
residues-fired; and 20 per cent would be biomass-fired). We estimate that
generating 1 GWhe would result in 37.2 TC emissions in Brazil in 2000, an
increase from today's 9 TC/GWhe. This coefficient would be very low by
international standards. The analysis also assumes that 16 per cent of total
generated electricity is lost in transmission and distribution losses incurred
in delivering power to the residential, commercial and public illumination
sectors.
The shift to greater thermal generation is a response to a series of problems faced by the power sector. These include: a profound financial crisis (hydropower is capital intensive); the large market uncertainty confronting supply planning (larger hydropower has long lead times); and the need to attract more private sector investment in generation, which tends to favour thermal power plants. A more hydropower-intensive scenario is conceivable but we have not reviewed this possibility as it would require extensive, system-level analysis beyond the scope of this chapter. It is noteworthy, however, that Brazil's thermal electrical sector would not be very carbon-intensive.
Other energy transformation
This end use includes all energy
inputs to extract and process fuel oil rigs, refineries, sugar plantations, etc.
Half of the sectoral carbon emissions are due to the conversion of fuelwood to
charcoal. As is generally the case with biomass fuels used in industry, the
production of charcoal is inefficient. This inefficiency can be greatly reduced;
this must be done in any case to ensure that fuelwood from sustainably managed
forests for charcoal manufacture is economically viable. Reducing conversion
waste in the charcoal fuel cycle will deliver the biggest abatement of carbon
emission in the subsector. Although less dramatic, incremental improvements in
efficiency are also available in most industries. These small but pervasive
gains would accumulate into significant reductions of fossil fuel usage and
carbon emissions.
Electricity final demand
Electricity generation will remain a relatively small source of CO2 emissions for many years in Brazil. Yet it is still desirable to reduce these emissions by demand side management. Many of these opportunities to increase efficiency have a large 'negative cost.' exploiting these opportunities will also relieve the financial pressures felt by the electrical sector in Brazil.
Residential sector
The residential sector consumes about 22 per
cent of total electricity and contributes 30-37 per cent of the electricity
evening peak. We have considered a range of technical options that could be
implemented in this sector up to 2000. For each of the following final uses, we
estimated the carbon abatement that can be obtained by improving electricity
end-use efficiency: lighting, water heating, refrigeration and air conditioning.
In Table 10.7, we show the technical and economic specifications for the new
technologies and those being replaced; the amount of carbon abated per year per
unit of equipment; the levellized annual cost of the new technology; and, in the
last column, the net costs when the annual value of the electricity saved is
deducted from the levelized costs.) A negative figure means that the new
technology brings economic savings, even before considering carbon credits.
Table 10.7 Residential sector technologies to limit CO2 emissions implementable by 2000
Old technology (1) | New technology (2) | Avoided C (kg/y/unit) (3) | Levelized annual cost ($/kg C) (4) | Annual cost of saved elec. ($/kg C )(5) | Net annual cost ($/kg C) (d) = (4-5) | Total C avoided (MTC/y) | Total net cost (million $/y) | |
Incandescent bulb (standard) | Efficient incandescent | 0.260 | 0.192 | 1.989 | -1.797 | 0.0385 | -69.26 | |
Lifetime (h) | 1000 | 1000 | ||||||
Power (W) | 60 | 54 | ||||||
Usage (h/y/lamp) | 1000 | 1000 | ||||||
Cost (US$/lamp) | 0.50 | 0.55 | ||||||
Incandescent bulb (standard) | Fluarescent (standard) | 1.560 | 0.485 | 1.989 | -1.504 | 0.1386 | -208.40 | |
Lifetime (h) | 1000 | 8000 | ||||||
Power (W) | 60 | 24 | ||||||
Usage (h/y/lamp) | 1000 | 1000 | ||||||
Cost (US$/lamp) | 0.50 | 7.00 | ||||||
Incandescent bulb (standard) | Compact fluorescent | 1.910 | 1.338 | 1.989 | -0.651 | 0.1129 | -224.50 | |
Lifetime (h) | 1000 | 8000 | ||||||
Power (W) | 60 | 16 | ||||||
Usage (h/y/lamp) | 1000 | 1000 | ||||||
Cost (US$/lamp) | 0.50 | 17.00 | ||||||
Electric shower | Solar shower | 17.350 | 4.146 | 1.989 | 2 157 | 0.2563 | 553.00 | |
Lifetime (y) | 15 | 15 | ||||||
Consumption (kWh/y) | 500 | 100 | ||||||
Cost (US$/unit) | 10.00 | 500.00 | ||||||
Refrigerator (standard) | Efficient refrigerator | 5.210 | 2.255 | 1.989 | 0.266 | 0.0857 | 22.80 | |
Lifetime (y) | 15 | 15 | ||||||
Consumption (kWh/y) | 600 | 480 | ||||||
Cost (US$/unit) | 200 | 280.00 | ||||||
Air conditioner (standard) | Efficient air conditioner | 7.460 | 1.297 | 1.989 | -0.692 | 0.0170 | -11.80 | |
Lifetime (y) | 12 | 12 | ||||||
Consumption (kWh/y) | 860 | 688 | ||||||
Cost (US$/unit) | 490.00 | 550.00 |
Lighting
Based on the present stock of residential lamps (220 million
incandescent lamps and eight million fluorescents), we estimate the stock in
2000. We assume that 50 per cent of old, inefficient incandescents will be
replaced by efficient incandescents; 30 per cent by fluorescents; and 20 per
cent by compact fluorescents. Such a programme would reduce carbon emissions by
0.29/MTC in 2000, providing a total net annual levelized benefit of US$502
million.
Water heating
In 1987,75 per cent of Brazil's 26.3 million electrified
households had electric showers. Assuming that the number of showers increases
by 2.1 per cent per year up to 2000 and further, that solar water heaters
achieve a 50 per cent penetration level in that year, we estimate that another
0.256 MTC can be conserved at an annual net cost of US$553 million.
Refrigeration
Refrigeration accounts for about 33 per cent of total
residential electricity use and is very wasteful (Jannuzzi and Schipper 1991;
Geller 1991). We projected the stock of refrigerators in the year 2000 based on
today's stock of 27 million. Assuming that 50 per cent of the stock in 2000 is
efficient, we estimated that 0.086 MTC can be abated at a total net cost in that
year of US$22.8 million.
Table 10.8 Commercial and public sector technologies to limit CO2 emission* implementable by 2000
Old technology(1) | New technology(2) | Avoided C (kg/y/unit)(3) | Levelized annual cost ($/kg C) (4) | Annual cost of saved elec. ($/kg C) (5) | Net annual cost($/kgC) (6) = (4-5) | Total C avoided (MTC/y) | Total net cost (million $/y) | |
Incandescent bulb (standard) | Efficient incandescent | 0.830 | 0.229 | 2.690 | -2.461 | 0.0053 | -12.95 | |
Lifetime (h) | 1000 | 1000 | ||||||
Power (W) | 100 | 48 | ||||||
Usage (h/y/lamp) | 1920 | 1920 | ||||||
Cost (US$/lamp) | 0.80 | 0.90 | ||||||
Incandescent bulb (standard) | Fluorescent (standard) | 4.330 | 1.309 | 2.690 | -1.381 | 0.0618 | -111.16 | |
Lifetime (h) | 1000 | 8000 | ||||||
Power (W) | 100 | 48 | ||||||
Usage (h/y/lamp) | 1920 | 1920 | ||||||
Cost (US$/lamp) | 0.50 | 22.50c | ||||||
Incandescent bulb (standard) | Compact fluorescent | 2.290 | 1.345 | 2.690 | -1.345 | 0.0485 | -96.26 | |
Lifetime (h) | 1000 | 8000 | ||||||
Power (W) | 60 | 16 | ||||||
Usage (h/y/lamp) | 1200 | 1200 | ||||||
Cost (US$/lamp) | 0.50 | 17.00 | ||||||
Fluorescent (standard) | Efficient fluorescent | 1.000 | 0.990 | 2.690 | -1.700 | 0.0645 | -109.68 | |
Lifetime (h) | 8000 | 8000 | ||||||
Power (W) | 48 | 36 | ||||||
Usage (h/y/lamp) | 1920 | 1920 | ||||||
Cost (US$/lamp) | 7.00 | 10.00 | ||||||
Incandescent bulg (standard) | Mercury/sodium | 15.050 | 1.928 | 1.548 | 0.380 | 0.015 | 5.74 | |
Lifetime (h) | 1000 | 12000 | ||||||
Power (W) | 175 | 80 | ||||||
Usage (h/y/lamp) | 3650 | 3650 | ||||||
Cost (US$/lamp) | 1.00 | 80.00b |
a Includes lamp (8000h), ballast (12000h) and light fixture (20000h).
b
Average cost of mercury and sodium package with 80% mercury lamps.
Air conditioning
We assumed that 2.85 million air conditioners will be in
use in residences in the year 2000. Of this total, 80 per cent will be installed
after 1990. We further assumed that all will be energy saving units. On this
basis, 0.017 MTC can be conserved in 2000 at a total net benefit of US$11.8
million per year.
Commercial, service sector and public lighting
Total energy
consumption of the commercial and services sectors has increased threefold
during the past fifteen years, and electricity accounts for more than 90 per
cent of the increase. We considered only opportunities to increase the
efficiency of lighting. In Table 10.8. we present the technical and economic
data for the new and old technologies, and quantities and costs of carbon
abatement. We assumed the current tariff for commercial electricity of
US$0.10/kWhe. (In the future, we would prefer to use an estimate of the economic
cost of electricity). We also assumed that 26 million incandescent and 48
million fluorescent lamps were used in these two sectors in 1990 (Jannuzzi et al
1991). We postulated a 2 per cent annual growth rate for incandescent sales and
3 per cent for fluorescents (taken as 40W lamps). We estimate that all the
incandescent lamps could be replaced in the year 2000 as follows: 20 per cent by
krypton-filled bulbs; 45 per cent by standard fluorescents; and 35 per cent by
compact fluorescents. This substitution would conserve 0.116 MTC of emissions
and increase total net benefits that year by US$220 million. Replacing all
fluorescents of 40W with more efficient 32W units with electronic ballasts would
conserve another 0.064 MTC, and increase total net benefits by US$110 million.
In Table 10.8, we also present results for improvements in public illumination. If 800,000 incandescent lamps are replaced by mercury lamps and 200,000 by sodium lamps, then 0.015 MTC could be conserved at an annual cost of US$5.7 million.
Industrial sector
To calculate industrial electricity demand in
2000, we assumed an average industrial economic growth of 3.5 per cent per year
(as suggested by the low growth 'tendencies' scenario) and the same energy
intensity (total energy/ GNP) as in 1988. We analysed electricity consumption
for each industrial subsector and factored in technological improvements
believed to be currently economic. We included the following measures:
housekeeping; efficient lighting; and more efficient electric motors, variable
speed electric motors, electric ovens, and electrolytic processes. We priced
industrial electricity at an average US$0.0581kWhe. In Table 10.9, we list
technical and economic data for these improvements.
Table 10.9 Industrial sector technologies to limit CO, emissions, implementable by 2000
(1) | (2) | (3) | (4)=(2)-(3) | |
Avoided carbon (MTC/y) | Levelized annual cost (US$/TC) | Annual cost of saved electricity (US$/TC) | Net annual cost (US$/TC) | |
Housekeeping measures | 0.32 | 409 | 1560 | -1151 |
Lighting | 0.02 | 988 | 1 560 | -572 |
High efficiency motor | 0.115 | 383 | 1560 | -11 77 |
Variable speed drivers | 0.197 | 357 | 1560 | -1203 |
Electric ovens and boilers | 0.152 | 197 | 1560 | -1363 |
Electrolytic processes | 0.075 | 389 | 672 | -283 |
Housekeeping measures
From many evaluations performed by electric
utilities (CEMIG 1989; CESP 1990) it is clear that electricity demand can be
reduced by 10 per cent with better end-use management. These measures should
include:
a better choice of electric motor size, especially by avoiding oversized motors which are common (Latone e' al 1990);
appropriate design of the factory's internal electric distribution grid;
installation of small size transformers in parallel with the main one, to be used during idle factory periods;
correction of the load factor;
avoidance of short term peak demand (through the use of demand controllers); and
better mechanical coupling between electric motors and the equipment driven by them.
These actions would conserve 0.32 MTC for a total annual net benefit of US$368 million.
Lighting
The industrial sector contains about 14 million fluorescent 40
watt lamps. We assumed that this stock grows by 3.5 per cent per year and that
all new lights will be the 32 watt efficient type (with new ballast). These
steps would conserve 0.020 MTC/year yielding a total annual net benefit of
US$11.3 million.
High efficiency electric motors
These devices are available in Brazil and
offer an improved average efficiency of 7 per cent. We assumed that 60 per cent
of motors will be replaced by high efficiency models up to the year 2000. This
step would save 3.1 TWhe in that year (Geller 1991), saving Brazil US$135
million and avoiding 0.115 MTC emissions.
Variable speed electric motors
Variable speed motors can be run partly
loaded without decreasing energy efficiency. More important, in applications
such as refrigeration and air circulation, such motors can operate partly loaded
with less energy consumption than do fixed frequency motors that provide only
on/off cycles. About 30 per cent of the total motor market (measured in
kWhe/year) is used to drive variable loads. If half of this load is met by
variable speed motors, Brazil would reap a total annual net benefit of US$237
millions and conserve 0.197 MTC.
Electric ovens and boilers
At least 10 per cent of the electricity used
in electric ovens and electric boilers can be avoided by recycling the exhaust
heat or by installing more efficient equipment (Geller 1991). We expect that the
retrofit rate will be low. Nonetheless, one third of the potential saving could
be achieved by the year 2000. We estimate that the total annual net savings that
year would be US$207 million, thereby conserving 0.152 MTC.
Electrolytic processes
Studies on electricity intensive industries (CNE
1989) have shown that improvements in electrolytic processes can reduce
electricity consumption by 7 per cent in metallurgical industries and by 10 per
cent in chemical industries. Brazil could avoid generating 2 TWhe by this means
in 2000, saving a total annual net benefit of US$21.2 million and reducing
carbon emissions by 0.075 MTC.
Final electricity demand summary
Modern technologies can improve
end-use electricity efficiency, although their cumulative impact on carbon
emissions is small in a country like Brazil where most of the electricity is
provided by hydroelectric power plants. We estimate that the potential to
conserve carbon in the residential, commercial, service, public illumination and
industrial sectors in 2000 is about 1.7 MTC - or only about 3.2 per cent of the
total fossil fuel carbon emissions of 1990. This result follows from the
predominance of hydroelectricity supply in Brazil. Nonetheless, these
technologies should be promoted in any case because most bring net economic
benefits. The few which involve net costs today should become cheaper as the
technology is accepted more widely and economies of scale are achieved. The only
high cost technology where this trend may not hold is solar heating to replace
electric showers.
Final fuel demand
The final consumption of fuels is the predominant source of CO2 emissions in Brazil (see Table 10.3). We focus on the transport sector in this section because it is the largest source of fossil CO2 emissions.
Transport
Transport is central to the achievement of carbon
emission abatement. In Brazil, this sector is responsible for 44 per cent of
fossil carbon dioxide emissions. Most (82 per cent) of these emissions come from
road transport (SNE 1991b). Transport-related carbon emissions result from three
broad factors: the carbon emission coefficient of the fuel used; the efficiency
with which different energy forms are used in different modes and markets; and
the demand for transport services in different markets and different modes that
serve these markets.
In this section, we review the measures which influence these three determining factors in the transport sector. Fuel substitution can modify the first factor, the carbon emission coefficient. Vehicle efficiency affects the second. 'Structural charges' influence both the demand for different modes of transport; and the performance of the vehicles operating within them, that is, the second and the third factors listed above. These first two classes of measures are dominated by energy sector objectives and priorities. The economics of the third, the category of 'structural charges,' is determined by non-energy societal benefits. Consequently, economic analysis of the third factor is more complex than for the first two.
Fuel substitution
The emergence of CO2 emissions as an
issue will have a profound effect on the development of substitutes for
petroleum derivatives in the long run. The only large scale commercial
substitutes in the world which reduce rather than increase emissions are ethanol
from sugarcane (the production of which is concentrated in Brazil) and
compressed natural gas.
Alcohol
Brazil's well-known alcohol programme (PROALCOOL) now fuels
nearly five million Brazilian cars with pure (hydrated) ethanol. The rest use a
gasoline-alcohol mixture. PROALCOOL is now in a difficult situation due to the
collapse of oil prices in 1986. Some have suggested that alcohol output should
be reduced gradually (World Bank 1990). We have not calculated the societal cost
of maintaining current output, nor the cost of increasing the output level. Such
an estimate should include the impact on sugar prices of reducing alcohol output
(Borrel 1991) and on employment - especially in the Northeast where the
sugarcane industry is in crisis. However, the net cost of merely maintaining the
output of alcohol should be lower than for expanding it (see Table 10.10).
The 'alternative' SNE scenario projected moderate growth of 2.1 million of tonnes of oil equivalent (MTOE) or 37 per cent by 2000, thereby increasing the market share of ethanol from 17 per cent to 19 per cent of total transport fuel. We adopted this estimate in our own scenario. This substitution would conserve about 1.5 MTC (see Table 10.10), even allowing for fossil fuel inputs for alcohol production. The net cost of this expansion is heavily influenced by assumptions as to gasoline prices. At a gasoline price of US$25 per barrel, we estimated the net cost of expansion to be US$2301TC. Changes in alcohol production technology may also substantially reduce costs by improving the utilization of the residues of sugarcane processing in the cogeneration of electricity. In Brazil, conventional steam turbine technology does not offer much hope of reducing alcohol production costs. But the new gasification/gas turbine (BIG/GT) technology could reduce costs significantly (Ogden et al 1990). Table 10.10 illustrates this possibility. Such major reductions are likely to be commercially proven only by the end of the decade.
Table 10. 10 Transport sector opportunities to limit CO, emissions by 2000, preliminary
Avoided CO2 (MTC)a | Net cost/TC (US$)a | |
FUEL SUBSTITUTION | ||
Alcohol: maintain existing output | 4.2 | not availableb |
Alcohol: expand output | ||
Current technology at $25/b gasoline | 1.5e | 230c |
Current technology at $35/b gasoline | 1.5e | 115c |
New technology at $25/b gasoline | very small | 75d |
New technology at $35/b gasoline | very small | -35d |
Natural gas | 0.2f | near zero (+,-) |
VEHICLE EFFICIENCY | ||
Improvement in automobiles | 1.9-2.5k | -135i |
Diesel engine | 0.9h | -30/-40 |
STRUCTURAL CHANGE | ||
Highway system recovery | 2.4g | 800g |
Improved urban transportation | 0.4-0.8l | near zero (+,-) |
a Includes rough estimates of fossil fuel inputs for alcohol production (15%
of alcohol output) and of refinery efficiency for gasoline (95%). Elsewhere in
column a 95% refinery efficiency is assumed.
b Estimated to be lower than
increasing alcohol output. Baseline scenario assumes maintenance of existing
output.
c Assumes a litre of hydrated alcohol is equivalent to 0.7 litres
of gasoline (small efficiency credit).
Cost of good exiting distillery is
$0.20 per litre. Allows for refinery efficiency of 95% in gasoline production
and fossil fuel inputs equivalent to 15% of alcohol production.
d Assumes
alcohol production cost of $0.14 litre, only available by end of the decode.
e Based on 'alternative' scenario relative to 1990 (see text).
f Based
on 'alternative' relative to 'tendencies' scenario.
g Assumes baseline of 14
MTOE diesel consumption and 3.7 MTOE gasoline in 2000 compatible
with
'tendencies' scenario assuming same proportion of total diesel and gasoline
transport use
as today. Assumes an average 15% improvement for all vehicles.
While up to 40% improvement
is possible from worst to best conditions, not
all of the roods needing improvement, about 50%
of the roads are in the
'worst' category.
h Assumes 25% of market of 21.4 MTOE in 'tendencies'
scenario shifted to this engine type.
i Assumes conservatively average
vehicle use at 45,000 km per year with 3-year engine lifetime,
engine 25%
mare expensive and average efficiency improved by 15%.
j Assumes existing
gasoline price ($0.26 per litre). Average cost of measures is $0.17 per
litre,
adjusting cast estimates of Ledbetter and Ross (1990), for 12%
discount rate.
k Ledbetter and Ross (1990) estimate US average fleet fuel
economy could increase 25% by
2000. Assume here that in 'tendencies'
baseline average Brazilian fuel economy increases to existing US level
(estimated at 9.2 km/litre).
l See text. This is the least defined case. It
helps to illustrate the impact of a relatively small effort to improve urban
transportation.
Natural gas
Natural gas is promoted as a substitute for diesel, primarily in public transport. The main goal is to reduce atmospheric pollution (NOx, SOx, particulates) in metropolitan areas. Several cities aim to replace all diesel in vehicle fleets by around 2000. The 'alternative' scenario estimates that 0.9 MTOE of natural gas may be used in this fashion which would conserve O2 MTC. Some of this gas may displace gasoline instead of diesel, since this is more lucrative at current relative prices. The cost of the measure (excluding environmental benefits) is near zero. That is, the natural gas option roughly breaks even with diesel at today's prices.
Road transport vehicle efficiency
Significant improvements in
vehicular fuel economy are possible. The rate of improvement will be determined
primarily by technological innovation in the automotive industry in the
industrialized countries and secondarily, by the pace that these changes
penetrate the Brazilian market.
Light vehicle efficiency
The current Brazilian automobile averages about
7.5 km/l (gasoline equivalent). The SNE 'tendencies' scenario projected an
increase of 30 per cent in light vehicle (basically automobile) fuel consumption
to 17 MTOE, incorporating modest improvements in fuel economy. We extrapolated
from US data on trends in automobile fuel efficiency (Ledbetter and Ross 1990),
and considered only measures that cost less when operated at the consumer retail
price of gasoline today. On this basis, we estimated that the average fuel use
of the automobile fleet could be decreased by 20-25 per cent relative to the
'tendencies' scenario, saving 3.4-4.3 MTOE of fuel per year.) The associated
carbon abatement depends on whether these savings cut gasoline rather than
alcohol usage. If we assume that two-thirds of the fuel saving is gasoline, then
carbon emissions would fall by 1.9-2.5 MTC. Based on US costs, the average cost
of these measures would be negative (see Table 10.10) - even if we ignore the
likely benefits of reducing the emissions of other local pollutants. Our
projected large fuel saving contrasts strikingly with that of the SNE official
'alternative' scenario, which projected that only 0.4 MTOE could be saved by
increasing automotive fuel efficiency.
Heavy vehicle efficiency
We estimated heavy vehicular fuel use from
figures available for diesel consumed by Brazilian road vehicles. On this basis,
this end use in 1990 was 15.5 MTOE. The SNE 'tendencies' scenario projected that
it would increase to 21.5 MTOE. More efficient diesel engines offer substantial
fuel savings at a zero or slightly negative net cost (Cummins 1991). We assumed
that 15 per cent of the fuel can be saved in this sector. As the initial cost of
the engine is about 25 per cent greater than less efficient motors, the net cost
would be US$30-401TC conserved. If the more efficient motors achieved a 25 per
cent additional market share than in the SNE 'tendencies' scenario, then another
0.9 MTC would be conserved. Other measures can improve heavy vehicle fuel
economy, including improved maintenance and motor regulation and more
appropriate sizing of vehicles to their tasks.
Structural changes
In this section, we outline structural changes
that foster energy efficiency. These are: the re-paving and rehabilitation of
the existing highway system; and the reform of urban transport to improve public
transport and the overall productivity of urban transport infrastructure. Both
approaches entail large public sector investments in which non-energy costs and
benefits usually determine policy decisions. Broad rather than narrow economic
analysis must be used to estimate the economic feasibility of these changes.
Highway systems recovery
Brazil has an extensive, but badly deteriorated,
intercity highway system. Roughly half of its 130,000 km system requires intense
reconstruction. The economic cost of this decayed infrastructure is high in
terms of trip time and reliability, vehicle maintenance and lifetime, and
hazard. The poor system also reduces energy efficiency. For inter-urban trucks
and buses the loss may be as high as 40 per cent on poor quality paved roads
relative to well-maintained roads (GEIPOT 1989). Assuming an average fuel
economy gain of 15 per cent and a baseline interurban vehicle fuel consumption
consistent with the 'tendencies' scenario, CO2 emissions in 2000
could be reduced by about 2.4 MTC. The investments required are large and the
lifetime of the assets is as short as five years (Lee 1991). The cost (if fully
charged to carbon abatement) could exceed US$8001TC conserved (including only
fuel savings). Much - perhaps most - of this reconstruction is economically
justified without reference to carbon emissions. In that case, the energy
savings and carbon abatement can be treated as a by-product obtained at zero
marginal cost.
Improved urban transportation
Approximately one third of transport fuel
is consumed in the capital cities and larger metropolitan areas. Changes in the
structure and operation of the urban transport systems can influence the
evolution of fuel demand, though the evaluation of this potential is still in
its infancy. Measures are diverse and include land use control, disciplining the
automobile's use of road space, coordinating traffic flow and strengthening
collective transport (Poole et al 992).
The city of Curitiba has already addressed the problem of urban transport in a comprehensive manner. The city has coordinated urban land use, roadspace and collective transport policy for more than fifteen years, and has improved bus systems and traffic controls. Fuel consumption per car in Curitiba is about 30 per cent less than the average for other cities of its size in Brazil (Lerner 1989). This differential may indicate the potential impact of such measures if adopted widely in Brazil.
An aggressive programme to address urban transport imperatives might result in CO2 emissions savings of 5-10 per cent relative to the SNE 'tendencies' scenario for 2000. This potential could be realized in spite of the inertia of a decentralized system involving thousands, even millions of actors. If lower cost solutions are emphasized in the next decade, then this energy and carbon savings could be achieved at zero net cost. Such measures would include creating and integrating public transport systems, and controls on traffic flow and parking.