Scielo RSS <![CDATA[Journal of Energy in Southern Africa]]> vol. 23 num. 1 lang. es <![CDATA[SciELO Logo]]> <![CDATA[<b>Measuring the indirect costs associated with the establishment of a wind farm: An application of the contingent valuation method</b>]]> Although a green energy source, the location of electrical generating wind turbines may cause a disamenity effect (negative externality). The establishment of a wind farm is known as a locally undesirable land use (LULU) and leads to the not in my backyard syndrome (NIMBY). In an application of the contingent valuation method (a survey technique which elicits individuals' preferences and measures these preferences in monetary terms) a willingness to accept a framework was used to estimate the aggregate annual compensation required to allow the construction of a wind farm near Jeffrey's Bay, South Africa. This compensation amounted to R490 695. A binary choice Logit analysis found that retirement status, concern about climate change, concern about view shed impacts and the offer amount are important predictors of voting for or against the project. <![CDATA[<b>Energy consumption and real GDP: Panel co-integration and causality tests for sub-Saharan African countries</b>]]> This paper investigates the causal relationship between energy consumption and real GDP in 14 Sub-Saharan African countries over the period 1971-2004. The results of panel co-integration tests showed that energy consumption and real GDP do not have a stable long-run equilibrium relationship. We find that for all members of the panel, there is homogenous causality from energy consumption to real GDP and vice versa. This bi-directional causality supports the feedback hypothesis. <![CDATA[<b>Bagasse-based co-generation at Hippo Valley Estates sugar factory in Zimbabwe</b>]]> The paper reports on the assessment of the use of bagasse for cogeneration purposes at Hippo Valley Estates (HVE), a sugar manufacturing company in Zimbabwe. Much emphasis was on an assessment of the quantity of energy that was lost due to inefficient combustion of bagasse and the use of steam that was generated. The study investigated the quantity of sugar cane processed and the possible corresponding steam produced; the sugarcane processed was found to be approximately 2.33 million tons per annum and the steam produced was 193.1 tons per hour. The steam was used in the process department as well as to drive mills. The excess steam generated was found to be 81.03 tons per hour. Economic analysis on the use of excess steam to produce extra power for sale to the utility company was also undertaken. It was established that the power plant for the company could generate an annual surplus of US2.8Million as revenue, and the payback period was found to be 3.3 years. The sensitivity analysis of the project indicated that the electricity prices as well as the energy produced were the most sensitive areas in the project. The other inputs such as operations and maintenance costs, interest, capital investment and number of years were not as sensitive as the price and the energy. <![CDATA[<b>Energy management of commercial buildings - A case study from a POET perspective of energy efficiency</b>]]> This paper aims at analyzing the energy management activities for commercial buildings of a financial service company in South Africa by energy efficiency in terms of performance, operation, equipment and technology (POET). The sustainability of a general energy management program is discussed within this POET framework. As an application of this discussion to the commercial building scenario, the award winning energy management program of this financial service group company is featured from the POET perspective of energy efficiency. The case study shows that the POET based framework can not only cover all major energy management activities, but also identify further energy efficiency improvement opportunities. <![CDATA[<b>Program-assisted sizing of a photovoltaic-powered water pumping system</b>]]> Climate change has had perhaps the most adverse effect on African rural communities where we witness persistent droughts and erratic rain patterns. Peasants often have to walk many kilometres to fetch water of a suspect quality. In these circumstances underground water supplies provide the best hope for them. Often, however, water tables may have receded to such an extent that wells are not a practical proposition. Besides, water is needed not just for domestic use such as food preparation and cleaning, but also for livestock and watering of small gardens. In this paper we present methodology for sizing and designing a photovoltaic pumping system based on components available in Southern Africa. We also show that solar pumping technology has gone past the experimental and prototype stage. Further we strongly put forward the proposition that the technology has clearly matured and in terms of cost, is fast approaching that of choice over other technologies relying on the grid. Currently the region faces an energy shortage and we see not only electricity cuts but those customers that actually are supplied with electricity face increasing and unacceptable tariffs. To make it more convenient we have consolidated the design process in a Visual Basic tool which is easy to use and apply. <![CDATA[<b>Hot water usage profiling to improve geyser efficiency</b>]]> This paper presents an intelligent hot water cylinder (HWC) (referred to as geyser) usage profiling system to provide peak demand side management and improve HWC efficiency in a typical household. The study highlights current control topologies used to improve geyser efficiency, as well as the design of the final geyser controller. The system consists of a PIC microcontroller used to determine individually based hot water usage profiles of the user. The controller then regulates the temperature of the geyser according to the demand profile developed. From the results it is apparent that by controlling the geyser temperature and thereby heat loss, savings can be made.