Inadequate energy supply is one of the major problems confronting Malawi and limiting its social, economic and industrial development. This paper reviews the current status of energy supply and demand in Malawi; examines the major sources of energy, current exploitation status and their potential contribution to the electricity supply of the country; discusses key issues facing the energy sector; and identifies broad strategies to be implemented to tackle the energy supply challenges. Using secondary data for its critical analysis, the paper also presents modelling of long-term energy demand forecast in the economic sectors of Malawi using the Model for Analysis of Energy Demand (MAED) for a study period from 2008-2030. Three scenarios namely reference (REF), moderate growth (MGS) and accelerated growth (AGS) were formulated to simulate possible future long-term energy demand based on socio-economic and technological development with the base year of 2008. Results from all scenarios suggest an increased energy demand in consuming sectors with biomass being a dominant energy form in household and industry sectors in the study period. Forecast results reveal that energy demand will increase at an annual growth rate of 1.2% and reach 5160 ktoe in 2030 under REF scenario. The growth rates for MGS and AGS are projected at 1.5% each reaching 4639 ktoe and 5974 ktoe in 2030, respectively. The final electricity demand of about 105 ktoe in the base year will grow annually at average rates of 13.8%, 15.3% and 12.6% for REF, AGS and MGS, respectively. Over the study period 2008-2030 the annual electricity per capita will increase from about 111 kWh to 1062, 1418 and 844 kWh for the REF, AGS and MGS, respectively. The final energy intensity will decrease continuously from about 13.71 kWh/US$ in the base year to 3.88 kWh/US$, 2.98 kWh/US$ and 5.27 kWh/US$ for the REF, AGS and MGS, respectively in the year 2030. In conclusion, the paper outlines strategies that could be utilized to ensure adequate supply of modern energy which is a key ingredient for achieving sustainable social and economic growth.

This paper briefly reviews the material and energy flows of the Malawian tea industry, in order to identify opportunities and reduce its environmental impacts. The review also details the concept and methodology as well as studies on applications of material and energy flow analysis. Environmental impacts are calculated with a life cycle assessment approach, using CML methodology. Results indicate that green leaf consumption in the studied factories ranged from 4.19 to 6.33 kg green leaf/kg made tea (MT), with an average of 4.96 kg per kg of made tea compared to 4.5 and 4.66 kg green leaf for tea factories in Kenya and Sri Lanka, respectively. Average wood consumption in Malawian tea factories is 3.35 kg/kg made tea and specific water consumption ranged from 1.92 to 8.32 kg/kg MT. In addition, the average value of greenhouse gas (GHG) emissions for eight factories is 4.32 kg of CO2-eq/kg MT as compared to 2.27 and 2.7 kg CO2-eq/kg in similar factories in Kenya and Sri Lanka, respectively. The major sources emitting GHG are from boiler fuel combustion and stand-by diesel power generation system. The study indicates that global warming has the highest environmental impact (88%), followed by acidification (6%) and eutrophication (2%), whereas human toxicity is lowest (<1%). The findings demonstrate how MEFA provides early recognition of environmental problems and how it can be used to establish priorities for improving operations in the existing factories.

This version is available at https://strathprints.strath.ac.uk/16427/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the AbstractThe effect of tank-interconnection geometry on temperature stratification in an integrated collector-storage solar water (ICSSW) heater with two horizontal cylindrical tanks has been studied. The tanks were parallel to each other, and separated horizontally and vertically, with the lower tank fitted directly below a glass cover, and half of the upper tank insulated. In addition, a truncated parabolic concentrator was fitted below the tanks, with its focal line along the axis of the upper tank. The heater was tested outdoors with the two tanks connected in parallel (P), and S1-and S2-series configurations, with and without hot water draw-off. Water temperature was monitored during solar collection and hot water draw-offs. For the heat charging process, it was found that only the lower tank exhibited temperature stratification in the P-and S1-tank modes of operation. There was satisfactory temperature stratification in both tanks in the S2-tank configuration. For the hot water draining process, the P-tank configuration exhibited some degree of stratification in both tanks. A significant loss of stratification was observed in the lower tank, with the upper tank exhibiting practical stratification, when the system was operated in the S1-tank mode. The S2-tank interconnection maintained a satisfactory degree of temperature stratification in both tanks. So, the S2-tank mode of operation was most effective in promoting practical temperature stratification in both tanks during solar collection and hot water draw-offs. Other results are presented and discussed in this paper.

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Crop residues have been undervalued as a source of renewable energy to displace coal in the national