Assessment of energy efficiency in Management in water supply - A Case study of Mzuzu water supply

Abstract

Energy is prime mover of all economic sectors. Therefore, efficient use of energy in the water sector would contribute to sustainable development. There are many social, economic and environmental benefits that can be realised once efforts towards effective energy management and energy efficiency measures are promoted. Developing countries have lagged behind in the implementation of energy efficiency and management measures hence missing the potential benefits of executing such projects. Malawi is one of the countries that has not fully utilised the opportunities in energy efficiency and management in the water utilities. This thesis has assessed energy efficiency and management in water supply system and is accomplished by investigating the existing level of energy efficiency and management practices in Mzuzu water supply as a case study. There are four methods which were used to come up with research findings; firstly, a survey was carried out using a structured questionnaire which was randomly distributed across the study area. Secondly, an energy audit was carried out in Mzuzu water supply system. Thirdly, energy Monitoring and Targeting (M&T) techniques were employed and used to establish existing relationship of energy consumed and water produced so that mathematical models can be established. Fourthly, Pumping System Assessment Tool (PSAT), was used to assess the efficiency of Mzuzu water supply pumping system. The outcome of the survey and energy audit expose that energy is poorly managed in water supply system due to lack of management commitment as evidenced by unavailability of energy policies, energy efficiency knowledge gap and insufficient funds to roll out implementation of energy efficiency measures. The audit captures correct power demand estimate, power factor correction and utilisation of changes in tariff by ESCOM in a 24-hour operational period as some of the areas where significant potential energy cost savings can be realised. Energy M&T techniques establish existing proven relationship between energy and water in the three pumping stations. PSAT analysis identifies low efficiency pumping systems and their associated energy savings potential in the study area. PSAT also show failed pumping system design in some of the pumping stations. The Plan-Do-Check-Act management model is recommended for continued energy savings and management gains.