Technical Review of Geothermal Potential of Ngozi and Songwe Prospects

Abstract

This paper presents the executive summary of the recently-completed geothermal resomce assessment report for the Ngozi ,-olcano and Song\Ye hot springs geothennal prospects in southwest Tanzania (Alexander et aL 2016). This report was prepared for the United Kations Em-ironment Programme (UNEP). As part of their initiati,-e to promote geothennal resomce de,·elopment and utilization in East Afi-ica. UNEP has implemented the GEF-ftmded Afucan Rift Geothermal DeYelopment Facility Project (ARGeo). One of ARGeo·s primary components is to pro,·ide technical and financial assistance for surface exploration studies for the ARGeo member com1tries (Btu-tmdi. Et-itrea. Ethiopia. Kenya. Malawi. Rwanda. Tanzania. and Uganda). In 2015. the recently-fonned Tanzanian Geothennal DeYelopment Company (TGDC) submitted a request for technical assistance to UNEP for surface exploration studies at the Ngozi and Songwe geothermal prospects (T ANESCO. 20 15). TGDC requested in its proposal proYision of scientific equipment and high leYel experts in areas of geology. geochemistry. and geophysics. UNEP chose this proposal as one of the projects for technical assistance for surface exploration studies. The Geothermal Dewlopment Company of Kenya (GDC) was nominated to proYide technical adYice and equipment for the stu·face exploration studies at Ngozi. Tiu-ee technical consultants were selected by UNEP to pro, ide adYisoty sen·ices and hands on training: Ketmeth B. (Keg) Alexander. geologist: William Cmmning. geophysicist: and Luigi Marini. geochemis t. This repo11 ,,·as prepared by the UNEP technical consultants. Preexisting and new geological. geochemical. and geophysical data ha,·e been compiled and e\·aluated to form separate. integrated resom·ce concepntal models of Ngozi and Songwe. The conceptttal models illustrate the ,·arious components of a geothermal system: heat sotu·ce. resen·oir. cap rock. temperattu·e distribution. and fluid patlm·ays. Alteruati,·e conceptttal models representati,·e of the llllcertainty in the data and interpretation are used for exploration well targeting and resotu·ce capacity assessment.