Performance Analysis of Garissa Off-Grid Power Station

Abstract

Off grid power generation options offer a cheaper and sustainable approach to electrify remote and rural communities. The main challenge associated with the use of a single technology is the danger of oversizing of the power systems at the project beginning hence high capital investment. Other limitations are high greenhouse gas emissions and low system reliability. Using a hybrid system and storage can overcome the intermittent nature of renewable energy sources and the problem of oversizing and improve the reliability of energy supply while at the same limiting the environmental impact related to use of fossil fuels. In this study, a performance analysis of Garissa power Station in Kenya was done. The study showed the power station had 6 diesel engine generators with a total installed capacity of 4,257 kW and effective capacity of 1,950 kW against peak demand of between 3600 for Garissa Town at the time of the study. Therefore, the town had a power deficit of 1650 kW during peak hours and therefore requires installed capacity of about 2053 kW (with engines availability factor of 80%) to meet the demand. However, based on the effective capacity factor, up to 3,587kW in new capacity was needed. This deficit was partially addressed temporarily by overhauling two engines of capacity 1064 kW that were out of service and which had been derated from a capacity 674 kW to 250 kW due to mechanical defects. Th study showed that generation improved by 44 by overhaul of engines 1 and 2 even though the generation from engines 5& 6 diminished due to expiry of after sales service and hence delays in maintenance. The study demonstrated the importance of proper and timely maintenance of diesel engines for reliable power supply and challenges associated with use of single technology in power supply for off grid systems.

Biogas Production and Process Control Improvements

“…Methane fermentation occurs naturally in the process of organic matter decay in oxygen-deficient environments like swamps and in landfills leading to the natural emission of methane to the atmosphere as a greenhouse gas. Controlled biogas production can be used to reduce these natural emissions [21,60].…”

“…Although lipids generate more biogas overall, carbohydrates and proteins convert more quickly [10]. Both biogas potential and yield are affected by the feedstock and co-substrates used in production, in addition to the process parameters [60,84,86].…”

“…The primary sources of animal waste commonly encountered include dairy shed effluent, mainly comprising of wash water, urine, dung, residual milk, and waste From Biomass to Biobased Products feed. Additionally, poultry litter, which encompasses water, manure, spilled feed, feathers, and bedding material, is another significant source [21,60]. Moreover, renderings from slaughterhouses and other byproducts originating from livestock finishing operations contribute to the overall volume of animal waste.…”

“…Moreover, renderings from slaughterhouses and other byproducts originating from livestock finishing operations contribute to the overall volume of animal waste. Dairy manure and poultry litter are widely recognized as prominent examples of animal wastes that are extensively be used in large-scale biogas energy production [60]. In the past, significant volumes of bovine excrement were subjected to treatment processes and subsequently utilized as a form of agricultural fertilizer, or alternatively, were disposed of through the practice of spreading onto farmland.…”

Biomethane Production and Applications

“…Biomethane as a fuel provides new opportunities at different levels for the society. In this chapter, various methods of biomethane production are described and compared [11,12]. There is growing interest in the use of biomethane as a renewable substitute of natural gas in applications like transport fuel which has created demand for biogas upgrading.…”