Quality of geothermal effluents and emissions from climate change resilient technologies in Eburru and Olkaria, Nakuru County, Kenya
MetadataAfficher la notice complète
Geothermal energy could be Climate Change Resilient subject to technological interventions employed in production. Kenya seeks to safeguard herself from Climate Change and its cascading impacts through clean energy sources such as Geothermal. Possible interventions to Climate Change entail adaptation, mitigation and building resilience. Most geothermal resources are located in fragile yet vital ecosystems including Olkaria and Eburru where the study focused on. A benign geothermal technology has to strike a balance between effective ecological functionality and economic prosperity for sustainability. There is urgent need to upscale stable energy provision while safeguarding important ecological zones necessary for Climate Resilience. The study determined the chemical characteristics of geothermal effluents and rain water. Trace elements analysed for these samples included Barium, Boron, Cadmium, Zinc, Lead, Copper, fluoride, sulphate, chloride, TDS and pH. Apart from these, concentrations of gases including carbon dioxide, methane, hydrogen sulphide and particulate matter were determined. Adequacy of technologies used in production were evaluated. This was achieved by analyzing gaseous concentrations and quality of effluents at various points of emissions and discharges. The capacity of intervening technologies to contain the fluid in a closed loop, or to minimize emissions and effluents, such as effluents re-injection were examined. The research design was exploratory since it offered integral insights as to the potential unintended consequences of geothermal energy. The research instruments used were focused group discussions, interviews, laboratory analysis, use of key informants and observations guide. Purposive, snowballing and simple random sampling were used. 80 wells were selected for sampling. One sample t-test was done using SPSS software at 95% confidence level. The results showed that geothermal exploration interfered with quality of borehole water. The p – value for fluoride at DCK borehole was 0.00 while its sigma value was 13.16. For discharging wells, p – value for boron concentration was 0.01 whereas its sigma value was 4.42. For well sites, p – value for zinc analysis was 0.00 while the sigma value was 3.98. The pH range for rain water was 5.76 to 6.86 which indicated acidic tendencies. Therefore, the constituents of discharging wells were ascertained to have high concentrations of trace elements that were toxic if released to the surrounding. The gaseous emissions further affected quality of rain water whose pH values were largely acidic. The gases released exceeded the permissible values for controlled zones. More so, the technological inadequacies were inevitable due to utilization of flash systems which had inherent handicaps. Average Carbon dioxide concentration was found to be 122.11 ppm which was above that recommended for controlled zones. Essentially, geothermal production had adverse impacts to the surrounding owing to technological inadequacies which resulted in discharge of toxic metallic concentrations to the fragile ecosystems that supported a wide range of species of plants and animals as well as social systems, all of which are imperative for cementing climate change resilience. The most benign strategy would be to contain the geothermal fluid within a closed loop system to minimize instances of emissions or effluents onto the surrounding.