Viability of substitution of electricity with biogas for thermal uses at Neudamm campus of the University of Namibia
No Thumbnail Available
Date
2025
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Namibia
Abstract
The growing demand for sustainable and affordable energy solutions in rural areas has
led to increased interest in biogas technology, particularly in developing regions. This
thesis presents the design and evaluation of a low-cost biogas digester for the
Neudamm Campus of the University of Namibia. The study adresses the campus's
energy cost and the underutilisation of livestock manure as a renewable energy
resource.
A 100 L digester, constructed from locally available materials, was fed with a cow
manure-water slurry and operated over a 60-day period. Key operational parameters
included an estimated 30-day hydraulic retention time, with pressure monitored three
times daily in the first week, twice daily from Days 8–21, and once daily thereafter..
The digester achieved an average daily biogas yield of 0.95 L, equivalent to 7.61 MJ
(2.11 kWh). Based on manure availability at Neudamm (22.2 tonnes/day), the system
could theoretically produce 318.76 L/day of biogas. This represents a payback period
of 2.5 years and an estimated 594% return on investment over a 10-year lifespan.
The gas produced was sufficient to substitute part of the campus’s electricity demand
for cooking and water heating, demonstrating both economic and environmental
benefits, including reduced greenhouse gas emissions and nutrient-rich slurry for
fertilizer.
The study acknowledges limitations such as short monitoring duration, reliance on
pressure as the sole gas measurement, and minor leakage issues.
ii
Despite these constraints, the study demonstrates the feasibility of low-cost, small
scale digesters in Namibia and provides a replicable model for rural settings. The
findings contribute to renewable energy knowledge in Southern Africa and highlight
practical opportunities for integrating biogas into campus and farm operations
Description
A thesis submitted in partial fulfilment of the requirements for the Degree of Master of Science in Renewable energy
Keywords
Biogas, Renewable energy, Sustainability, Namibia, University of Namibia