Implementation strategy to reduce environmental impact

of energy related activities in Zimbabwe

Working Paper No. 5

UNEP Collaborating Centre on Energy and Environment

Risų National Laboratory, Denmark

January 1997

Southern Centre for Energy and Environment

Zimbabwe

National Environmental Engineering Research Institute

India

UNEP Collaborating Centre on Energy and Environment

Denmark

Southern Centre for Energy and Environment

31 Frank Johnson Ave., Eastlea

P.O. Box CY 1074, Causeway

Harare

Zimbabwe

phone/fax: +263 4 737351/739341

National Environmental Engineering Research Institute

Nehru Marg

Nagpur-440 020

India

phone: +91 0712 226071 to 226075

fax: +91 0712 226252

UNEP Collaborating Centre on Energy and Environment

Risų National Laboratory

P.O. Box 49

DK-4000 Roskilde

Denmark

phone: +45 46 32 22 88

fax: +45 46 32 19 99

Foreword

Contents

1 Introduction

2 Background on the energy sector in Zimbabwe

3 Environmental impacts of energy related activities

4 Review of studies on energy efficiency in Zimbabwe

5 Barriers to implementation of negative cost options in Zimbabwe

6 Proposed implementation strategies

7 Role of multi-lateral and bi-lateral institutions/agencies in technology transfer and diffusion 63

8 Action plan

Annex I: Evaluation of select combustion technologies

Annex II: NO_x emissions from different combustion technologies

Annex III: Air pollutants from various electricity-generating technologies

Annex IV: Comparison of baghouse filters and electrostatic precipitators for control of suspended particulate matter emission from coal combustion

Annex V: Commercially available processes for the chemical cleaning of coal to remove sulphur before combustion

Annex VI: NO_x control technologies

1 Introduction

1.1 Country background

Zimbabwe's economy has sizeable commercial agriculture, manufacturing and mining activities. Energy consumption is relatively high by regional standards. The country has substantial coal reserves. All petroleum products are imported. Wood fuels are widely used by the rural households and by low income urban households as the main source of household energy.

In view of a current economic reform programme which has opened the local market to foreign finished products and looks to an export led economic expansion strategy, the manufacturing sector in Zimbabwe has to become internationally competitive if it is to hold its share of the domestic market and to gain a position on the international market. This requires stringent management of production costs and product quality assurance. Alongside these pressures exist pressures of rational energy use and sound environmental management. A significant amount of cost management measures relate to energy efficiency which has direct benefits to cost savings. Sound environmental management, however, which has become an obvious expectation of the market can if managed proactively yield optimum resource utilization at the shop floor resulting in cost savings. But if done reactively, environmental management interventions normally show up as costs from which the company sees no gains.

In the Zimbabwean situation energy efficiency management is low and proactive environmental management is limited as companies are either not carrying out any rational energy use and environmental management practices or are focusing on "step one" activities such as energy and environment audits as opposed to the more sophisticated approaches involving resource use optimization.

Energy and environmental management issues also show up on the supply side of the equation both as costs to the economy and as negative effects on the environment. In the past more than 12% of GDP was spent on expansion of power sector. As Zimbabwe needs energy to raise productivity and improve the living standards, energy demand would increase in future thereby entailing greater investment costs to the economy and perhaps expanded environmental degradation from energy supply and utilization activities. Historically the country's energy needs have been met by expanding the supply base with little attention being paid to the efficiency of energy use. This approach is now, however, raising serious financial, institutional, and environmental problems. The magnitude of these problems underlines the need for devising strategies for improving the efficiency with which energy is currently produced and used and the approaches adopted for sound management of environmental impacts of the energy sector.

During this and other studies on related issues, it became evident that indeed there is no fundamental difference of opinion and purpose among the various stakeholders on matters of energy efficiency and environmental management. Rather, Zimbabwe is in a unique situation where industry, government and NGOs agree on the objective of rational energy use and sound environmental management and together have made various efforts to device workable approaches to enhance this objective. Industry, working mostly through the Confederation of Zimbabwe Industries' specialised committees on energy and environment, holds consultations with Government and research institutions toward this goal. The Department of Energy and the Ministry of Environment and Tourism's Environmental Planning and Monitoring Unit have carried out a number of activities either through studies or through legislative reform in light of pressure from the national consensus on matters of energy and environment.

Despite these efforts, very little actual progress has been made in improving industrial energy efficiency and in adopting rational environmental practices. At first sight, it might appear that there is lack of intent but the flurry of activities in this area do not confirm that conclusion. Rather, as the study has found out, there are some genuine barriers to these efforts.

The study documented below focused on these barriers and on suggesting approaches to their removal. As background and to build a context to its analysis, the study provides a rather extensive review of the energy sector but focuses mainly on coal and electricity and the environmental impacts of their supply and utilization.

1.2 Project objectives

Energy-Environmental linkages have assumed greater importance in the recent past as the impact of green-house gases (mainly CO₂) on climate change was realized. However, in Zimbabwe, pollution has remained at a low level. Pollution assessments have been carried out under the Ministry of Health through the Air Pollution Control Unit and by the Ministry of Public Service, Labour and Social Welfare who assess emissions of dust from coal as well as work place exposure to hazardous chemicals and emissions.

In 1992 UNEP-Collaborating Centre on Energy and Environment (UNEP-CCEE), Denmark and Southern Centre for Energy and Environment (SCEE), Zimbabwe, prepared a country report for Zimbabwe on Greenhouse Gas (GHG) Abatement Costing. Abatement technologies for both supply side and demand side were identified in the study to reduce GHG emissions.

UNEP-CCEE's work on the Greenhouse Gas Abatement Costing Studies confirmed that for most developing countries, including Zimbabwe, scheduling GHG abatement options is likely to follow regular national development activities agenda and much less an agenda for mitigating global environmental issues. This national agenda would stress mitigation of local pollution and environmental degradation if environmental issues are at all included in the national development programme. This may mean that in the energy sector GHG emissions abatement may be achieved but only as a bonus on activities intended to mitigate local environmental problems.

As environmental issues related to energy sector are very extensive, the present study endeavours to address environmental impacts of the entire energy cycle focusing on coal use in industry and power generation. Zimbabwe has proven coal reserves of more than 700 million tonnes, and the potential of geological coal resources is estimated beyond 30 billion tonnes. The conventional applications of coal include electricity generation, steam traction in railway transport, industrial boilers, tobacco curing, and coking. As coal is the major source of energy for Zimbabwe, present study aims at identification of environmental impacts of the entire coal cycle from mining to end-users of electrical energy.

In view of above and the interest expressed by the Ministry of Transport and Energy in taking up practical measures to pursue environmentally sound energy development strategies, the present project endeavours to examine the issues which may have a bearing on a strategy to implement sound environmental management in the energy sector.

In view of the fact that energy, like capital and labour, is a key input to production processes, the objective of the strategy developed in this report is not to pursue energy efficiency as an end in itself, but as a means to an end where the end includes minimizing total costs of production as general focus.

The scope of the study, accordingly, includes:

Delineation of present sources of energy, projection of future energy demand and collection of information on energy sector development plans.

Delineation of broad environmental impacts due to energy related activities.

Detailing environmental impact due to coal mining and coal based thermal power generation.

Development of emission scenarios for energy sector development plans.

Delineation of technological options to reduce pollution due to coal mining and thermal power generation.

Delineation of barriers to implementation of environmentally sound energy technology.

Delineation of institutional and financial mechanism to implement the emissions reduction measures.

Delineation of the different roles of multi-lateral and bi-lateral institutions and agencies in the transfer and diffusion of sound energy supply and end-use technology.

Formulation of action plans for implementing strategies for minimizing negative environmental impacts of energy related activities

1.3 Institutional arrangements for the study

The study has been jointly carried out by UNEP-CCEE, Denmark, Southern Centre for Energy and Environment (SCEE), Zimbabwe and National Environmental Engineering Research Institute (NEERI), India. UNEP-CCEE and NEERI experts visited Zimbabwe in January and May 1994, interacted with the government officers, industries and financial institutions to collect necessary data. This study report has been jointly prepared by the participating institutions.

1.4 Limitations of present study

The major limitation of the study is that it was carried out in a situation where the present status of energy related environmental pollution is unspecified. Information on air pollution, water pollution and land degradation due to energy related activities has not been systematically documented. For this reason, it was not possible to assess impacts of pollution prevention or control strategies in terms of improvements in local environmental quality in quantitative terms due to the lack of a bench mark upon which to judge such improvement.

2 Background on the energy sector in Zimbabwe

2.1 Sources of energy

Zimbabwe relies mainly on coal for thermal energy in industry and power generation. This fuel provides the bulk of industrial energy and produces about 70% of total national electrical energy. Electricity is also produced from hydro resources of the Zambezi. Biomass (mainly fuel wood) is the main source of energy for rural household who represent about 77% of total households in the country. The energy balance for Zimbabwe for 1991 which is shown in Table 2.1 shows a detailed breakdown of source and applications of energy among the various economic sectors of the economy. The figures indicate the dominance of wood in the national energy base. Wood has not been a commercial fuel in the past but is becoming more so particularly in urban areas. All petroleum products used in the country are imported.

Sources and applications of each of these fuels are discussed in greater detail below.

2.1.1 Hydroelectricity

The major source of hydropower for Zimbabwe is Zambezi river which has a total potential of 7200 MW of which 4200 MW can be developed by Zimbabwe jointly with Zambia. The two countries share a hydroelectric power station on the Kariba dam which was built on the Zambezi river in 1955-1960. The present total capacity is 1266 MW which was developed as follows:

4 x 150 MW gen sets that were installed on the Zambian side and commissioned in 1962. These sets which are known as the North Bank Power Station are shared equally between Zambia and Zimbabwe giving each country a 300 MW share of the station.

6 x 110 MW gen sets which were installed on the southern bank (the Zimbabwe side) of the river in 1976-77 and are known as Kariba South Bank Power Station. This later installation brought the Kariba dam's hydro-electric power capacity to 1266 MW and under the equal share agreement, Zimbabwe owns 633 MW of this capacity.

The Kariba Power Station has recently been affected by drought and the flows into the lake have been progressively low since the early eighties, resulting in a critical fall in levels which almost rendered the station in-operable in 1992/93. In August 1993, the lake level was about one meter above the power station intake level and projections were putting the water to last till November 1993. The drought resulted in change of preference towards thermal plants which are less affected by poor rains. The Zambezi offers additional hydroelectric resources at Batoka gorge, Devil's gorge, Mupata gorge and at Cahora Bassa in Mozambique. The potential hydroelectric resources are shown in Table 2.2.

Sites for mini hydro plants in Zimbabwe have been assessed but the total potential has not been stated. Table 2.3 shows some of the potential sites and their capacity based on historical performance of their hydrology.

Table 2.2. Potential hydroelectric resources on River Zambezi

Source: ZESA

Table 2.3. Potential mini-hydro sites in Zimbabwe

Source: DOE study on hydroelectric potential of irrigation dams.

2.1.2 Coal

Zimbabwe has a total of 10.6 billion tonnes of coal in situ in 21 deposits. Coal deposits occur in the younger rocks at the northern and southern edges of the basement shield. Proven reserves can last for 107 years and total reserves over 2000 years at present production rate of 4.7 million tonnes per year (TPY). A breakdown of coal reserves in the country is shown in Table 2.4.

Table 2.4. Coal reserves in Zimbabwe

Source: DOE/ESMAP

The country has two coal mines. One is the Wankie Colliery with production capacity of 6 million tonnes per year. Of the present output of 4.5 million tonnes per year, 2 million tonnes are processed and sold as industrial washed or dry coal and 2.5 million tonnes are used as run-of-mine steam coal at the Hwange power plant. The second mine is the Sengwa Coal Mine with production capacity of 200,000 TPY which was shut down after two years of operation due to viability problems. The mine produced low-sulfur, low-phosphate metallurgical coal for the smelting industry, to displace import of high quality coal from South Africa. Wankie coal has 2.5% sulphur compared to Sengwa coal with 0.5% sulphur. Both types of coal have an average calorific value of about 27 MJ/kg.

Wankie colliery has both surface and underground works. Proven reserves at Wankie are 302 mn M.T. (185 mn M.T. of steam coal and 117 mn M.T. of coking coal). Out of these 240 mn M.T. are open-castable. The surface mine produces a low quality high ash content (25% ash) coal from the top of the seam. This coal is termed the HPS (Hwange Power Station) coal and is used entirely for the Hwange Power Station. Coal with an ash content of 35% to 40% is rejected as waste. The lower part of the seam produces higher quality steam coal, less than 16% ash, which is supplied to industry and agriculture. The bottom of the seam produces coking coal which is used for supplying to the coke ovens at the colliery and at ZISCO, a steel smelter. Underground coal is produced for blending with the coking coal in the processing plant. Underground coal has a sulfur content of about 3% but has a low phosphorous content which makes it suitable for the ferrochrome industry. The coal has a heat value of about 28 MJ per kg. The underground mine produces 15% of the total colliery output and it is planned to increase output by mechanizing. Proven coal reserves at Sengwa are 200 mn M.T. which is totally open-castable.

2.1.3 Thermal power stations

Coal-based thermal power generation assumed an important role in energy supply scenario of Zimbabwe since 1984 when Hwange Power Station was built at the Wankie coal mine. At present, Zimbabwe has an installed coal based thermal capacity of 1295 MW with a total annual coal intake of 2,856,673 tonnes a year in 1990-91. The role of coal in power generation is highlighted in Table 2.5. The details of present installed capacity and power station performance are presented in Table 2.5 and 2.6.

Table 2.5. Role of coal in power generation

Source: ZESA Annual reports

Table 2.6. Power station technical data

Source: ZESA Annual report 1993

The Kariba South units are being uprated to about 125 MW, and a similar exercise is in progress at Munyati and Harare.

Table 2.7. Electrical energy production and station performance for 1993

Source: ZESA Annual report 1993

2.1.4 Fuel wood

Wood is the single largest source of energy in Zimbabwe, supplying about 48% of total energy consumed in the country. More than 6 million tonnes of wood are consumed annually supplying mainly rural and urban low income households. This is equivalent to clear felling of 100,000 ha; or a sustainable yield from two million hectares of reasonable quality woodland. This is also equivalent to a yield from more than 10 million hectares of sparse cover on rough grazing land. Demand for fuel wood exceeds supply in four of the eight provinces (Manicaland, Mashonaland East, Masvingo and Midlands). Early in the next century, only Mashonaland West and Matabeleland South, provinces with the lowest population densities, are likely to retain a wood surplus.

Table 2.8. National fuelwood supply and demand (million tonnes)

Source: The Southern African environment, profiles of the SADC countries, 1993

2.1.5 Liquid fuels

Zimbabwe does not have known oil reserves. There has been some exploratory work in the Zambezi valley but no deposits have been identified yet. The transport sector relies on imported liquid fuels which are brought in by pipeline from Beira in Mozambique to Mutare and are distributed by road and rail. A project is underway to extend the pipeline to Harare.

The fuel is used in the transport sector only. There is no extensive use of fuel oils in industry. Kerosene is used to a limited extent and some boilers exist that use diesel but the fuel use is insignificant and can be ignored. Petrol is mixed with ethanol to form a blend that is used for petrol engines. The ethanol production is based on sugar production.

2.1.6 Renewable energy sources

Biogas

Biogas offers an option for supply of household and agro-industrial energy in Zimbabwe. More than 200 digesters have been installed in Zimbabwe which range in capacity from 3 cubic meters to 16 cubic meters. The basic feedstock is cow dung or pig manure. Two types of biogas digesters have been introduced in the country which has no tradition with this type of technology. These are the Indian and Chinese types.

Initial dissemination constraints were encountered due to lack of a local source of biogas lamps. A local source has now been developed and with all other materials for the technology being locally available, the diffusion of this technology should be much faster than hitherto experienced.

Solar and wind energy

Zimbabwe experiences an insolation of 2000 kW/m² per year. Insolation is uniform across the country and across the seasons.

Wind speeds in Zimbabwe are relatively low at only 3.2 m/sec. Information recorded by the meteorological office shows that the highest wind speeds are experienced at Bulawayo (4.25 m/s), Chipinge (3.8 m/s) and Gweru (3.8 m/s). These speeds are irregular both by season and by area and vary widely diurnally. This wind regime rules out utilization of wind energy for power generation. This resource is however sufficient to enable utilization of wind mills for water pumping.

At present there are a few companies supplying wind mills for power generation.

2.1.7 Electricity imports and other sources

Other energy resources in Zimbabwe include electricity imports from Zambia (up to 300 MW) which depend on the flows on the Zambezi and imports of about 120 MW from Zaire. Electricity imports are limited by load growth in the exporting country. Imports from Zambia are expected to stop by 2000. The electricity system is also interconnected with South Africa at Beitbridge and with Botswana at Francistown. Imports from South Africa offer a more expensive option and would only serve as emergency support. Even then, a 500 MW interconnection with South Africa will be completed by the end of the year. System interconnection, however, serves to improve reliability as outages in one system can be compensated by the other.

At the Triangle sugar mill, bagasse is burnt to produce electricity. The plant can produce up to 15 MW during the harvesting season and 5 MW out of season. Electricity is used on the plant and is also sold to ZESA consumers in the area when there is a surplus. There is a recent power purchase agreement between ZESA and an independent producer in the Chimanimani area. The electricity will be produced by a 700 kW mini-hydro plant and will be sold entirely to the utility. This agreement has served to indicate the willingness of the utility to purchase private power, an option which has been missing in the energy sector in Zimbabwe. The tariff agreement provides for a guaranteed price of 80% of the ZESA tariff which assists in project planning for new producers.

2.2 Present energy consumption pattern

Commercial energy demand in Zimbabwe is for manufacturing industry, mining, agriculture, transport, commerce and households. Industry uses most of the coal based energy for steam raising and furnaces and as electricity from the coal fired power stations. The final energy consumption is shown in Table 2.9.

Table 2.9. Energy consumption by fuels (TJ)

Source: DOE energy data base

2.2.1 Coal

Thermal power generation is the prominent user of coal seconded by the manufacturing sector. Coal is also used in agriculture for tobacco curing. Most of the industrial energy is supplied from coal. Coal is used for steam raising and smelting in furnaces. There is a coking plant at the colliery in Hwange and at the Zisco Steel plant in Redcliff. A total of about 534,000 tonnes of coke is consumed in industry every year.

Table 2.10. Coal consumption by sector for 1990 (tonnes)

* Lowveld sugar industry only

** Inclusive of other sugar refineries

Source: WCC Annual report

2.2.2 Liquid fuels

Liquid petroleum fuels are imported as refined products. There is no refinery in Zimbabwe as the only refinery build before independence was closed on commissioning due to UN imposed sanctions in 1965. The fuel is transported by pipeline to Mutare from where it is transported by road and rail to major distribution centres. Transportation by road is very expensive and to reduce this cost, a pipeline is being built from Mutare to Harare.

The main categories of liquid fuels that are imported are diesel, gasoline, kerosene and aviation fuels. Almost all liquid fuels are used in the transport sector except for very small quantities which are used in industry for oil fired boilers and boiler starting and flame stabilization at Hwange power station. The power station consumes about 15 million litres of diesel per year. The low income household sector also uses kerosene for cooking and lighting.

In the transport sector the large vehicles for road freight and public transport are entirely diesel powered. The government has therefore maintained a differential price between diesel and petrol as a way of protecting agriculture and commerce. Gasoline is used mainly for light motor vehicles and is blended with locally produced ethanol at 13% ethanol to 87% gasoline.

Aviation fuels are supplied in two main groups mainly Jet A1 and Aviation gas (Avgas). Jet A1 is a light fuel for jet engines and avgas is used for mainly small piston aircraft engines. The table below gives the figures of liquid fuels imported in 1991.

Table 2.11. Liquid fuel consumption 1991

Source: DOE data base

2.2.3 Electrical energy

Analysis of electricity consumption in various sectors is presented in Tables 2.12 and 2.13. It could be seen that even though industrial energy consumption has reduced by 8.39% in the period 1990-93, still it consumes 40% of total electricity produced. Another interesting feature to be noted is that demand from the commercial sector and lighting has been increasing over the years. These two sectors hold potential for implementation of energy efficiency measures.

While total domestic demand has also increased substantially, it is not clear from available data whether the increase is due to rural electrification or due to increased use of electrical appliances in presently electrified households. However it is noteworthy that in the past three years ZESA has been increasing the rate of new household connections in the urban areas.

Table 2.12. Electricity sales by consumer classification

Source: ZESA Annual report 1993

Table 2.13. Electricity sales by consumer classification

Source: ZESA Annual report 1993

2.3 Energy demand projection

2.3.1 Assumptions

The following assumptions were used in making energy projections shown in Table 2.14. The projections are based on energy demand and macro-economic data presented in the UNEP/Southern Centre GHG Abatement Costing Study for Zimbabwe carried out in 1993. These figures included the following:

Analysis of the energy use by fuel figures for Zimbabwe for 1980 to 1992 which shows no major change in percentage contribution of each fuel to the total national energy balance.

GDP projections presented in the UNEP/Southern Centre GHG report. These were adopted as correct together with the figures for energy intensity of production and the Autonomous Energy Efficiency Improvement Factors assumed in that report.

Energy intensity factors and AEEI values for the Zimbabwean economy.

An additional assumption was made that the percentage contribution by fuel will remain as in 1990 and the total energy use can be split by fuel using those figures in the forecast years.

For the electricity sector which forms a key segment in this study, the present ZESA

development plan was adopted.

Table 2.14. Energy demand by fuel in TJ

Source: Southern Centre projections

2.3.2 Coal demand forecast

Since the opening of the Hwange power station in 1984, coal demand has been dominated mainly by coal requirements for electricity generation. Before that, the supply regime was geared more toward industrial demand for boiler coal and for coke. In the future, coal demand will be influenced more by the following factors.

Power generation at Hwange units 7 & 8 which are to be commissioned in the year 2000. This will result in an additional coal demand of 1.1 million tonnes per year

From the year 1995 to year 2000, regional hydropower of 400 MW will be available through Cahora Bassa line. This will reduce the demand for coal for electricity generation in this period unless ZESA chooses to maximise domestic generation by base loading its thermal units.

Refurbishment of old thermal power plants which is due for completion by year 1996. These plants will then re-enter the electricity supply system and account for additional coal demand.

Economic growth driven increase in coal demand for mining and products such as base metals, tobacco, pulp and paper and textiles.

It is also expected that the adoption of energy efficient technologies would reduce energy intensity of industrial production and thereby place downward pressure on coal demand. This factor, however, is not expected to have a significant influence as economic growth would have an upward push on demand.

Department of Energy Resources and Development of Zimbabwe, in 1992, and the Energy Sector Management Assistance Programme (ESMAP) of the World Bank carried out an exercise to develop an integrated energy strategy for Zimbabwe. The exercise projected coal demand up to 2010 based on growth trends in energy demand for the period 1981-89. Coal demand was projected for a number of scenarios. These included:

A trend case with a GDP growth rate of 3.0% p.a.

A policy-neutral case with a GDP growth rate of 4.5% p.a. and little or no energy demand management practised.

A policy active scenario with a GDP growth 4.5% p.a.

and a demand management case involving measures to improve energy efficiency.

Using data in these scenarios, this study revised the policy active scenario and produced new projections shown below in Table 2.15.

2.3.3 Liquid fuel demand forecast

Liquid fuel demand is dependent on the vehicle mix and fleet size. As the economy grows there will be a larger population albeit of more efficient motor vehicles. Demand for road transport for freight will increase with the increased demand for movement of manufactured goods. It is difficult to make demand projections for liquid fuels based on historical trends due to the changes in economic policy that have caused a major shift in economic activities. Further, liquid fuel demand is not considered for assessing environmental impact in present study.

Table 2.15. Coal demand forecast 1989 to 2010 ('000 tonnes)

Source: Southern Centre/ESMAP

2.3.4 Demand forecast for electricity

The electrical energy forecast for Zimbabwe has been based on knowledge of historical demand regressed to project future demand. The demand projection is typical of developing systems where the early pattern is almost a straight line that changes to exponential function as the economy grows. Successes achieved with the use of historical data in the short term have been due to the system being still in the first part of the curve and the dependence of the supplied demand on utility investment. There are a number of developments in the country that are set to increase domestic load significantly. These include the following:

The economy has a large number of (mainly domestic) consumers whose demand is not being met due to limited investment on the part of the utility, and the potential additional demand could be 100 to 200 MW.

There are a few industrial projects that are in the pipeline including a 38 MW platinum mine and the construction of several industrial entities in the major cities.

There has been a very large country-wide housing development initiative by both the private sector and government, and urban accommodation is now virtually built for connection of electricity.

It is therefore forecast that demand will increase steadily in the foreseeable future. The ZESA load forecast shown below is based on trend analysis and the development plans submitted by industry.

Table 2.16. Electrical energy demand forecast (GWh)

Source: ZESA load forecast

2.4 Energy supply options

The system development plans for ZESA are based on the criteria that the internal generation should be equal or excess to the demand and the system should be planned for a minimum reserve of 25% with imports exceeding or meeting the reserve margin.

The current development plans include refurbishment of the existing plants, augmenting cooling capacity and control equipment upgrading at the Hwange power station, construction of interconnectors, and construction of new plant at Batoka, Sengwa, and Hwange. Demand Side Management is not included in the ZESA's development plans. The following section provides some information on the utility's system development plan and a list of major projects indicating the sequence and dates.

2.5 Management structure of the energy sector

The Ministry of Transport and Energy is the responsible authority for energy policy and for public administration of the energy sector in Zimbabwe. The organ responsible for the day-today administration of this sector is Department of Energy in this Ministry.

The Department of Energy (DOE) is headed by a director who reports to the Permanent Secretary in the Ministry.

The DOE does not have exclusive control over all matters in the energy sector. A number of other institutions including other Government Ministries, international oil companies, private mining companies and the National Railways of Zimbabwe influence activities in this sector particularly with respect to pricing of energy products such as coal and petroleum.

Management of the coal sector falls under the Ministry of Mines, and the involvement of the Ministry of Energy is mainly as a major consumer through ZESA which operates all coal thermal power plants in the country.

Table 2.17. Zimbabwe electrical energy supply system development plan

The projects carry a total investment cost of US $ 2804730-00

Source: ZESA

Table 2.18. Electrical energy development plan

Source: ZESA

Coal mining in Zimbabwe has until 1989 been the monopoly of the Wankie Colliery Company, a subsidiary of the Anglo American Corporation. This company mined and controlled the only economically viable deposits in the country, the Wankie Concession area. Following independence in 1980 Government took 40 % share of the colliery company and allowed a second company Sencol, a subsidiary of Rio Tinto Zimbabwe, to mine a second deposit at Sengwa. Sencol coal is mainly used in the steel industry.

Wankie Colliery Company operates on a Government guaranteed cost-plus pricing formula and controls 100% of the coking coal market and 95.6% of total coal production in the country. The significance of this monopoly is that the company has had no cause to improve production efficiency.

The electricity sector is the sole supply domain of Zimbabwe Electricity Supply Authority (ZESA) which generates, imports and distributes all electrical energy in the country except for a few small private generators run either as stand alone systems in remote communities or as back-up systems by large urban companies and in some schools and hospitals.

3 Environmental impacts of energy related activities

3.1 Energy environment linkages: a general overview

Environmental impact is any alteration of environmental conditions or creation of a new set of environmental conditions, adverse or beneficial, caused or induced by the project under consideration. Impact on environment depends on the nature, scale and location of the activity. Environmental impacts include effects on the natural resource base; quality of air, water, noise, biological & socio-economic components of environment; effect on public health and also cost of environmental management.

The range of environmental issues related to energy generation, transmission and use is very extensive. The relative significance attached to different environmental issues varies widely. Environmental problems have to be considered in terms of:

global issues, particularly global warming

national or regional issues, where the scope is a few hundred or thousand miles

local impacts (i.e. within a few miles of an energy facility)

workplace exposure to high temperatures, dust, particulates, sulphur dioxide and high humidity for industry and agriculture.

Local environmental concerns raised by coal fired power generation relate to the environmental pollution caused by the following activities:

coal mining and storage in the mining premises, as well as its transportation, handling, crushing and storage in the power station premises,

coal combustion, steam generation, which contribute to GHG emissions

condenser cooling water disposal and wastewater treatment.

These activities are discussed in greater detail under section 3.3 below.

Local impacts, which are generally site-related, are perhaps the longest established category. The environmental damage can range from the aesthetic (impact of thermal power plant in remote countryside) to airborne pollution (particulate deposition from fossil fuel use) to ecological change (flooding in hydro schemes).

The national/ regional category of environmental impacts which mainly include acid rain and global warming is mainly of post-second worldwar vintage. CO₂ is responsible for around 50% of the impact of the various greenhouse gases associated with global warming. The energy sector as a whole is responsible for the great bulk of this and the power sector is in turn responsible for the majority of the energy sector's contribution. It is therefore clear that at all levels coal combustion in the electric power sector is a major contributor to environmental problems.

3.2 Global issues

3.2.1 Global warming

Carbon dioxide occurs naturally in the atmosphere and plays an important role in almost all living organisms. Measurements show that its concentration has been on the rise, and since industrialization it has gone up by nearly 25 percent. The main cause is considered to be burning of fossil fuels, during which carbon contained in the fuels is oxidized and released into the atmosphere. The destruction of forests has also contributed to this rise as the vegetation provides a sink for roughly one half of the carbon dioxide released into the atmosphere stays while the other half is absorbed by the ocean and plants. Prediction models suggest that as a result of the combined effect of increased emissions of CO₂ and other green house gases the Earth's average surface temperature would increase by 1.5 to 4.5^oC (UNEP, 1993). This seemingly marginal increase will have far reaching consequences in terms of changes in climate, rain fall patterns, agricultural practices and sea levels.

3.2.2 Acid rain

Coal is composed of carbon, hydrogen, oxygen, nitrogen and sulphur with small amounts of other trace elements. When coal is burnt in an adequate amount of oxygen, its combustion produces heat energy as a result of the chemical reactions which take place when the combustible components of coal viz. Carbon (C), Hydrogen (H) and Sulphur (S) are oxidized. The sulphur present in coal is of two types:

Inorganic Sulphur (mainly present as pyrites)

Organic Sulphur (forms the part of overall coal matrix)

Most of the inorganic sulphur can be removed by coal beneficiation techniques but only part of organic sulphur can be removed by chemical treatment although at exorbitant costs.

The oxides of sulphur (SO_x) and of nitrogen (NO_x) are the principal chemical pollutant products of coal combustion. When these gases are emitted by the power station chimneys, over half of the emissions fall to earth in dry form, relatively near the source. In the presence of sunlight and other chemical oxidants present in the atmosphere, some of the remaining air-borne sulphur and nitrogen oxides are transformed into sulphites and nitrates and finally these sulphites and nitrates form H₂SO₄ and HNO₃. These acids which deposit in wet form about 200-1000 km away from the source are known as acid rain.

The impacts of acid rain are most pronounced on:

Quality of lake water and aquatic habitat

Vegetation

Fertility of sensitive soils and

Mutilation of monuments and structures of immense architectural value

3.3 Local environmental impacts

3.3.1 Environmental impacts of coal mining

Coal production involves acquisition of large surface land both for underground and opencast mines and results in varying impact on environment and ecology.

Air borne emissions from coal mining consist of particulates, NO_x, CO, hydrocarbons and sulphur compounds. These emanate at mine, coal and waste storage piles and preparation plants. However, the impact is normally limited to local areas. Uncontrolled fires resulting from spontaneous combustion in abandoned mines and coal piles overburden dumps produce noxious gases. Surface mining emissions come from diesel equipments and blasting operations. The air quality impacts of underground mining are negligible.

The environmental problems of serious nature related to coal mining are:

Land degradation

Change in land use patterns due to mining and disposal of overburden

Deforestation during the mining operation

Soil erosion and land slides

Disruption of drainage pattern of the area

Run-off waste from mines, soil dumps, coal dumps leading to siltation in stream/water bodies

Water quality degradation due to discharge of mine water into streams, water bodies etc.

Leaching and erosion of coal dumps and waste dumps

Air pollution due to dust and noxious fumes

Noise and ground vibrations

Socio-economic factors like displacement of families and rehabilitation

Health and safety of workers

3.3.2 Environmental impacts of coal transportation

Coal is more difficult to transport compared to liquid petroleum products because of its bulky form. Frequently, more than one transportation mode is required to move it to the point of consumption. The environmental impacts of coal transportation are spread over the total distance of the transportation corridor and are often not immediately visible. The impacts include habitat loss, community disruption, fugitive dust, increase in noise, and accidents in developing transportation corridors. During the actual transportation of coal the impacts are generation of fugitive dust, smoke and noise.

3.3.3 Environmental impacts of coal based thermal power generation

Environmental impacts of coal based thermal power generation relate to coal handling, storage and combustion at the power station. The major environmental impacts of coal handling activities at the power plant relate to noise, solid waste generated in coal crushing, and the fugitive dust emissions therefrom. Coal is burned in boilers to generate steam. During this process gaseous, liquid and solid pollutants are generated. Gaseous emissions during coal combustion include suspended particulate matter, carbon dioxide, nitrogen oxide and sulphur dioxide.

Atmospheric emissions of solid particles during coal combustion usually vary in sizes from 0.01 to 10 micrometre in diameter. While large particles are removed by the emission control system efficiently, smaller particles are difficult to capture. These smaller particles in the range of 0.01 to 1.0 micrometre are easily respirable and have adverse effect on human health. The smallest of particles get deposited in the alveoli of pulmonary regions while the larger ones tend to be deposited in the nasopharyngeal and tracheobronchial regions. These particles remain in the respiratory system for 2 to 6 weeks. However, particles of a size less than 0.01 micro metre in diameter are not usually deposited in the respiratory systems.

For every million Kcals released by the combustion of coal, 385 kg of Carbon Dioxide is emitted. Concern has grown over the climatic changes brought about by increased carbon dioxide levels in the atmosphere because of its absorption of infra-red radiation from the earth. High levels of carbon dioxide in the earth's atmosphere would produce the "Green House Effect" which is understood to be increasing the global temperature.

The oxides of nitrogen are produced by oxidation of nitrogen in air during coal burning, and to a much lesser extent by the oxidation of nitrogenous compound in coal. The environmentally important species of nitrogen oxide are nitric oxide and nitrogen dioxide. Nitrogen oxide is a strong irritant and can cause inflammation of the lungs as well as damage to crops and forests when combined with sulphur dioxide from acid rain.

Sulphur dioxide (SO₂) is formed as a result of oxidation of sulphur present in coal in the process of combustion and it escapes into the atmosphere and gets deposited locally or is converted into sulphuric acid or sulphates. Its impacts include human health hazards, damage to crops and forests, metal corrosion and acid rain.

The liquid waste problems associated with thermal power plants are due to discharge of wastewater from the following different sources:

Circulating water from condensers

Overflow from ash pond

Boiler blow down

Cooling tower blow down

Wastewater from regeneration of demineralization plant

Wastewater from water treatment plants viz. sludge from clarifier and backwash water from filters etc.

Wastewater from oil storage and handling area

Wastewater from equipment cleaning including boilers

Rain-fall run off from coal pile storage

Floor drains etc.

These wastewaters contain residual chlorine, chromium/zinc sulphates, dissolved and suspended solids. As temperature of these wastewaters is higher than ambient temperature, discharge of wastewater in waterbodies affects the aquatic ecosystem downstream of discharge point.

Ash produced in a thermal power station is of two categories viz: bottom ash and fly ash. During coal combustion, as much as 80 to 85% of the incombustible fines leave with combustion gases as fly ash, the remainder is collected as bottom ash. The bottom ash is collected in boiler bottom hoppers and fly ash in electrostatic precipitator hoppers. Normally the ash is dumped in low lying waste areas where about 10 to 15 metres of depth is available which helps in reclaiming the land. If such land is not available man-made lagoons near the power stations are created. If the size of the fly ash pond is smaller than that desirable, especially in older plants, a substantial amount of fly ash is carried into the river system. Improper construction and maintenance of fly ash dykes causes breaches and subsequent pollution of the receiving water body.

3.3.4 Environmental impacts of coal utilization in industry

Coal is used in industry for steam generation in boilers and smelting furnaces. Both these operations require coal transportation, storage and combustion. Compared to thermal power plants efficiency of coal utilization in industry is low. Environmental impacts of coal utilization in industry are similar to those of thermal power plant. However, total emissions are distributed over a large area.

3.4 Energy related environmental issues in Zimbabwe

3.4.1 Coal mining

Major problems in coal mining in Zimbabwe relate to water pollution, coal fines disposal and emissions from the coke ovens plant. The problem of overburden disposal at Wankie Colliery Company is partly reduced due to use of overburden coal in Hwange power station.

In Zimbabwe, effluent from mining works is monitored adequately and controlled, but toxic residues do enter the ecosystem as usually sterile, sometimes toxic, waste. The major legislations controlling pollution from mining activities are the Hazardous Substances Act and the Atmospheric Pollution Prevention Act, which are administered by the Department of Environmental Health in the Ministry of Health. Major problems in implementation relate to lack of infrastructure and instrumentation facility for monitoring.

The Wankie colliery has a processing plant which screens coal according to pebble sizes and also washes coal for the coking plant and for industry. Washing reduces the ash content and the sulfur content. The waste water from the washing plant is recycled but some water is lost through evaporation and spillage. The coal dust removed through washing is settled out of the water and is piled in dumps. The washing process takes about 40% of the colliery output and recovers about 88% of the coal that goes through the process and is aimed at reducing ash content to below 10%. The colliery now uses a centrifuge to recover washery water as opposed to settling tanks which caused higher losses. The colliery has plans to blend waste from the washery with coal fines, which are 10% to 20% of total production, to produce coal with about 25% ash. Trials are underway to use the coal fines in the production of electrical energy at the Hwange Power Station.

From the 2 million tonnes of the processed coal, the Wankie Colliery generates fines at a rate of 9 percent of total. To date, between 2 and 3 million tonnes of these fines have accumulated. Coal fines are presently stockpiled to waste at the coal washing plant at Wankie Colliery. The stockpiled fines represent an environmental hazard in the form of (potentially explosive) dust or through filtration into the soil or ground water systems of the acid from the iron pyrite present in the coal.

About 584000 tonnes of coke are produced every year for industrial use, most of which is in the iron and steel industry. Coke is now a preferred option for firing bricks since it can be mixed with the clay and fired at a better efficiency. The coke ovens produce by-products such as benzol, tar, ammonia and coke oven gas. The benzol is sold to a chemical plant for distillation and the tar is sold as fuel to industry. The ammonia is disposed of in wastewater and the coke oven gas is flared. A project for the coke oven gas to be used in the power station for boiler starting and flame stabilization in place of diesel has already been constructed and is to be commissioned soon.

The Mines and Minerals Act in Zimbabwe overrides most other acts in that few restrictions are attached to the exploitation of mining rights once the mining permit has been obtained. Thus, the Act does not prevent extensive tree cutting without reforestation, poaching by mine workers, siltation, dumps and non-compliance with quittance requirements when mines are closed.

Wankie colliery has initiated rehabilitation and revegetation programme on a pilot scale in abandoned mine sites.

3.4.2 Coal combustion

No documented information is available related to environmental impact of thermal power generation in Zimbabwe. However, it is known that Hwange power station has installed Electrostatic Precipitators for removal of flyash. A desulphurization unit is not installed. Also, Hwange power station is facing a flyash disposal problem.

In the absence of institutionalized environmental monitoring mechanism, data on industrial sources of air pollution and status of pollution control is not available.

3.4.3 Ambient air quality

Limited data is available for ambient air quality monitoring undertaken by the University of Zimbabwe for locations near Harare city which is presented in Table 3.1. It is evident that even in 1988, levels of SO₂ in the City Centre and industrial area were very high. Harare and Bulawayo experience smog during winter. The major problem in air pollution control relates to lack of monitoring facilities. The only facilities in Zimbabwe for air sampling and analysis are located at University of Zimbabwe. Urban councils are expected to monitor sources of air pollution and ambient air quality. However, these councils do not have infrastructure for the same.

3.5 Environmental policies and institutions in Zimbabwe

3.5.1 Environmental legislation

Major enactments in Zimbabwe related to environment are:

Natural Resources Act (1941)

Forest Act (1981) Amendment

Parks and Wildlife Act (1975)

Mines and Minerals Act (1961)

Hazardous Substances and Articles Act (1977)

Atmospheric Pollution Prevention Act (1971)

Water Act (1976)

Regional Town and Country Planning Act (1976)

Communal Land Act (1982)

Communal Forest Produce Act (1982)

Rural District Council Act (1988)

Table 3.1. The maximum and minimum levels of gases at Mazoe Farmlands, Mt. Hampden and University Campus (1990)

Ambient concentrations of gases (1988) (microgram/m³ under STP)

* figures in parenthesis are total number of samples

Source: Jannalgodda, S.B. and Mathutbu, Environmental Quality Assessment: Studies on Air and Water Quality in Harare, Zimbabwe

The Mines and Minerals Act overrides all other acts and mines can be set up wherever minerals exist and at times with serious environmental consequences. Air Pollution standards in Zimbabwe have been adapted from international standards. The country has been divided into 17 smoke/dust control zones to facilitate air pollution monitoring.

A major problem with environmental legislation is the fragmented nature of the legislation and the lack of enforcement power in the Ministry of Environment and Tourism.

3.5.2 Environmental management institutions

In Zimbabwe, the Department of Natural Resources (DNR), which is under the Ministry of Environment and Tourism, is responsible for setting standards for environmental quality, mitigation of adverse impacts of new projects and providing information on environment. The major thrust of DNR is environmental education. Water Pollution Advisory Board (WPAB) in the Ministry of Agriculture and Water Resources monitors water pollution around urban areas. There is an Air Pollution Control Unit in the Ministry of Health which monitors levels of atmospheric pollution. The Ministry of Land, Agriculture and Water Development is responsible for soil conservation practices. The Ministry of Health and Child Welfare is responsible for various health related practices in industry. An overview of environmental management institutions in Zimbabwe is presented in Table 3.2.

3.5.3 Future direction for environmental management in Zimbabwe

Environmental issues are taking an increasingly high priority in Zimbabwe. The Government presented its National Conservation Strategy (NCS) in 1987, which aims "to integrate sustainable resource use with every aspect of the Nation's social and economic development and to rehabilitate those resources which are already degraded". The NCS proposed setting up an Environmental Monitoring Unit, creating a separate Ministry of the Environment, and establishing an Inter-Ministerial Committee for the environment to co-ordinate the implementation of the NCS.

Progress has been modest so far. The Ministry of Natural Resources and Tourism was recently renamed the Ministry of Environment and Tourism, but the Environmental Monitoring Unit and Inter-Ministerial Committee are not yet active. Responsibility for environmental policy remains scattered among a variety of Ministries and Boards in Zimbabwe, including the Ministry of Health (for air pollution), the Ministry of Energy and the Ministry of Water Resources and Development (for water pollution and energy conservation), the Natural Resources Board, and the Forestry Commission.

Monitoring and enforcement of environmental standards is not co-ordinated and therefore lacks effectiveness. Fines for infringing standards, which in some cases remain at the nominal level set in 1971, do not provide sufficient incentive to invest in pollution abatement equipment. In addition, foreign exchange constraints in the 1980 made it difficult for industries to invest in "cleaner" or more energy efficient process technology or equipment.

Table 3.2. Environmental institutions in Zimbabwe

Source: The Economic Implications of Limiting CO₂ Emissions in Zimbabwe, January 1992

The Ministry of the Environment is now in the process of preparing action plans to implement the NCS, and the Confederation of Zimbabwe Industries (CZI) is taking an active role in promoting environmental awareness and spreading best practices among its members. In addition there is a variety of non-governmental organisations active in the environmental field. The emphasis of environmental policy will clearly be on local pollution issues - particularly problems of water pollution in the areas around Harare and Bulawayo, degradation of land in communal areas, and the adverse impact of deforestation on fuelwood supplies and soil quality.

Industrialists in Zimbabwe are now concerned with three possible consequences of failing to heed the global and national calls for better practices. These are:

the negative effect on selling their products in European and American markets which might use environmental regulations and environmental performance as non-tariff barriers for exports,

the possibility of introduction and enforcement of harsher local environmental legislation if they fail to take positive initiative

the possibility that the new policy and legislation may happen without their input

The implications of continued environmental damage at the production level should provide sufficient impetus to industry to carry out responsible environmental actions. This situation is one where self-interest and national-interest coincide.

3.6 Environmental impacts of proposed developmental plans in energy sector

In Zimbabwe, coal meets more than 45% of the total energy demand followed by fuel wood which meets 40% of the demand. The implementation of strategies to reduce demand is more conceivable in the organized industrial sectors (thermal power generation and manufacturing) than in the domestic sector utilizing wood. Hence, the development of emission scenarios in the present study is limited to impact of coal utilization. While reduction of greenhouse gases is directly related to reduction in demand, reductions in emissions of other gaseous, liquid and solid wastes is a function of the control technologies that are adopted. In the absence of data on present status of pollution control no attempt is made in the present study to develop alternate scenarios. The scope of this study is thus limited to highlighting alarming dimensions of the environmental impact of energy related activities. This could convince decision makers on the necessity of formulating national policies and developing appropriate institutional mechanisms as recommended in the study.

The approaches adopted in the present study for developing emission scenario comprise:

Forecasting coal demand for years 1995, 2000 and 2010

Estimation of theoretical emission factors assuming average coal composition as that for Wankie Colliery based on ultimate coal analysis and 100% combustion

Survey of emission factors available in literature for coal mining and coal combustion

Working out total emissions for the present and projected coal demand for coal mining and coal combustion in thermal power plants and industries

Data that is currently available on the above actors is given in Tables 3.3 to 3.7 while Table 3.8 gives some information on the impact of capacity expansion of coal-based thermal power plants.

Table 3.3. Emission factors for coal mining

Table 3.4. Comparison of emission factors for coal based power plants

Note: Particulate emission include both flue gas emissions and ash

Normally ESPs recover 99.5% of particulate matter

Source: Stern, A.C. (1977). Air Pollution Vol. IV, Engineering Control of Air Pollution, Academic Press, London

Edgar, T.E. (1993). Coal Processing and Pollution Control, Gulf Publishing Company, London

WHO (1982). Rapid Assessment of Sources of Air, Water, and Land Pollution, WHO Offset Publication No. 62

Table 3.5. Emission factors adopted in present study

Table 3.6. Total emissions from coal mining

Table 3.7. Total emissions from coal combustion (tonnes/year)

80-85% of particulates would escape to atmosphere unless arrested in pollution control systems

Table 3.8. Impact of capacity expansion of coal based thermal power plant

3.7 Options for minimization of environmental impacts

Energy demand is bound to increase in future and so will the magnitude of adverse environmental impact. The mitigation options available include devising and implementing strategies for:

Reduction of adverse environmental impacts related to coal based power generation and coal use in industry through reduction in electricity/coal demand

Installation of pollution control devices in thermal power plants and air polluting industries

Restoration of environmental quality through reclamation and revegetation of abandoned mine sites

Reduction of environmental impacts through coal/electricity demand management is the most preferred option. This could be achieved through curtailing auxiliary consumption in thermal power plants and implementation of energy conservation measures in industrial units. Energy conservation measures range from improved house-keeping to adoption of energy efficient technologies. Apart from benefiting the environment, these measures would also result in net savings to industry and conservation of valuable coal resources. Thus energy conservation is a "negative cost" option. The institutional mechanism to generate awareness about energy conservation and trained manpower to develop energy efficiency programmes are, at present, inadequate in Zimbabwe. Also, promotion of energy efficient technologies would require careful selection, acquisition and adaptation of technologies. It is, thus, necessary to have a national focal point to address these challenging tasks.

After reducing environmental impacts by energy demand management to the extent possible, it will be necessary to employ environmental management technologies to further reduce impacts. A host of technologies are available for the control of air and water pollution, and for solid waste management. A review of these technologies is presented in Annexes I to VI.

The economic viability of these technologies depends on size and location of source of pollution (thermal power plant/industry), and the selection of appropriate technology requires data on source and ambient air/water quality. At present there is no centralized institutional mechanism for environmental monitoring. Environmental legislation is fragmented and lacks implementation due to inadequate infrastructure. Development of institutional set-up with proper instrumentation facilities and trained manpower is a pre-requisite for enforcing existing legislation for effective pollution control.

Information on environmental damage due to air/water/solid wastes from energy related activities is not available. Wankie Colliery Company has tried a restoration and revegetation programme for abandoned mine sites. Restoration of environmental damage would require co-ordinated effort on the part of industry and the government.

In the past, with participation of the Government of Zimbabwe, projects were undertaken through international funding to assess energy-environment linkages and potential for energy conservation. Most of the recommendations of these studies are yet to be implemented. Barriers to implementation of the recommendations have been assessed in the present report so as to:

identify steps that should be taken to improve on-going programmes

establish mechanism for expanding existing institutional set-up to effectively implement energy conservation and environmental management programmes

suggest the structuring of a national focal point for energy efficiency programmes in the form of an autonomous centre to assist industry and government departments

4 Review of studies on energy efficiency in Zimbabwe

4.1 Approach

The present study considers "negative cost" options as part of the implementation strategy to minimize negative environmental impacts. It has been established in several studies that there exist negative cost or economically viable options for industry in energy conservation. Industries have however not taken up the options even after study reports have been presented to them indicating viability of the options. Options suggested in various studies so far have been reviewed herein.

4.2 Options suggested in UNEP Greenhouse Gas Abatement Study

During the UNEP funded greenhouse gas country studies several options were considered for the reduction of carbon dioxide emissions in Zimbabwe. The options included energy use in industrial processes. The economic evaluation of the options considered the capital cost as given in project feasibility studies and quotations obtained from equipment suppliers. The analysis then modelled the fuel use and the operation and maintenance costs of the reference case and the reduction option given the project lifetime. Annual costs were derived which showed the cost of the project in relation to the reductions in carbon dioxide emissions per year. The analysis was from the point of view of the economy and therefore taxes and duties were not included.

The following table shows some of the results obtained. The table does not include positive cost options which are not the concern of this study.

Table 4.1. Summary of options in UNEP GHG abatement studies in Zimbabwe

The energy saved in 2010 is an indication of the penetration to be achieved by the efforts at that time. This information was based on the knowledge of the economy and the potential for energy conservation. Some of the projects like the Coke Oven Gas option are being implemented by industry for economic purposes.

The above graph shows potential savings of 69.6 PJ in 2010 and 178 PJ in 2030, representing respectively, 15% and 24% of total demand. These are significant amounts of savings for industry and they should generate sufficient interest from government and industry especially when it is considered that the conservation options will benefit the economy as well. The following is a description of some of the options for energy savings.

The option of using coke oven gas for Hwange power station has been accepted and is being implemented by the Wankie Colliery Company and ZESA to reduce the consumption of Diesel fuel. The option is being implemented not as an environmental protection measure but as a cost cutting measure for the WCC, ZESA and the government.

Zimbabwean industries rely on the locally produced boilers for process steam raising. The boilers are made under license and 70% of the market is supplied by a single manufacturer. The manufacturer designs boilers to an efficiency of 74%. This level of performance can be achieved through correct operation of the boiler including fuel quality, water quality, fuel air mixture and boiler maintenance. In some companies the following areas where improvements can be achieved have been identified:

steam blowers are not used regularly,

the air/fuel mixture is not monitored,

water treatment is not employed,

fuel quality fluctuates and boiler controls are not checked frequently.

The resultant efficiency of the boilers was therefore estimated at 50% on the average. The study assumed that the boilers could be redesigned to an efficiency of 79% as opposed to the current 74% and operation procedures could also be improved. No measures are initiated for implementation of the option.

The Zimbabwean industry also relies on locally produced electric motors. Before the recent liberalization of the economy, foreign exchange controls and the closed economy allowed the manufacturer to concentrate in meeting the demand without improvements in motor quality. In fact limitations in foreign exchange availability encouraged the use of low quality laminations and windings. The motors are generally very bulky in proportion to the horsepower ratings, and the manufacturer also does not have a test facility for efficiency measurements. The study assumed that industrial motor efficiencies could be improved by 15% on the average by redesigning the motors. However, high efficiency motors are not available in Zimbabwe or Southern Africa.

4.3 Options suggested in SADC Industrial Energy Conservation Pilot Project

The SADC Industrial Energy Conservation Pilot Project was implemented under CIDA funding by a Canadian consultant with three SADC counterpart staff. The project was carried out in four SADC countries namely Zambia, Zimbabwe, Botswana and Malawi. The project tasks included training in energy auditing, building awareness, and assessment of the energy conservation potential in the region. The key criteria for selection of companies was that they had to be small to medium manufacturing plants. This gives an indication of the capacity to invest and the availability of technical expertise to implement energy efficiency projects.

The project was implemented through surveys of industry which were fully funded by CIDA. The surveys analyzed energy use in general and produced some estimates of energy conservation potentials in industry. The conservation options were categorised as no-cost, low cost and medium cost and high cost. No cost measures included improved house keeping and equipment repair. Even though repair and maintenance cost money it was assumed that these measures are included in the normal operation and maintenance costs of the plant and should be implemented anyway. Low cost and medium cost measures included retrofits such as boiler efficiency improvement equipment or instrumentation, condensate reclamation, steam pipe insulation and coordination of steam usage. The investment in low cost measures would mostly cover labour costs.

High cost measures included the installation of new plant and equipment which would add to the value of the plant such as heat exchangers, pumps, light fittings and process equipment.

The SADC project did not classify the options as negative cost or positive cost. However the criteria of simple payback (SPB) gives an indication that an investment will payback within its lifetime. The options had their simple payback calculated to indicate financial viability. Table 4.2 below shows the results of the SADC studies and the potentials for conservation in energy and financial terms. The options include reduction of thermal losses, process efficiency and lighting retrofits. Apart from establishing potential conservation options the project compared energy intensity in industry to best industry practice in other countries.

Table 4.2. Conservation options identified by the SADC Pilot Project

4.4 Options considered in Zimbabwe Energy Efficiency Project (ZEEP)

The Zimbabwe Energy Efficiency Project was commissioned by government (Ministry of Transport and Energy) to address the issues of energy efficiency in the economy. The first phase of the project was meant to identify potential options for conservation that can lead to viable investments in energy conservation. The project was being done with a background of rising electricity tariffs and shortage of electrical energy capacity in the system. The project was funded through the International Energy Initiative (IEI) by the Rockefeller Foundation. The project is meant to continue beyond 1996 when various physical projects may be implemented as part of the National Development Programme. The major players identified for the project were the utility (ZESA), the Department of Energy in the Ministry of Transport and Energy and private consultants. Utility participation has been limited to the review of reports and sporadic participation at some of the project meetings. It has not yet been established why the utility participation is so limited. Perceived benefits from the project are generally agreed to be reduction in expenditure on investments for energy and reduced utilisation