A technical-economic analysis and environmental impact assessment of power recovery at a city gate station: a case study

Abstract

ABSTRACT In many countries, natural gas is dispatched to the end-users by using pipeline configurations with a high pressure. The gas pressure must be dwindled at city gate stations before ingression into the distribution network. The hydrocarbon turbo-expander can be applied in such stations and regains this pressure as electricity. The present study presents the techno-economic feasibility of power recovery at a city gate station in Iran. On the grounds of exiguity of economic data regarding application of turbo-expander to resuscitate power at city gate stations, this paper has tried to devote greater attention to the financial and economic dimensions. Technical analysis suggested two different capacities of 616.7 kW (option A) and 815.6 kW (option B). The financial analysis exposed that option A with a positive NPV of 71 thousand Euros, an IRR of 17.13%, a normal payback of 7.7 years and a discounted payback of 15 years is favorable while with a negative NPV of −191 thousand Euros, option B is not feasible. The investigation established that power price is the most predominant determinant while operating costs have negligible effect on the results. Furthermore, by inputting the cost-benefit analysis of CO2 dissemination into the economic model, it is transpired that with a positive NPV of 1009 thousand Euros and a significant IRR of 45% for option A, and a positive NPV of 406 thousand Euros and an acceptable IRR of 25% for option B, the two alternatives are more economically viable. Substantively, from the public standpoint, both options are more desirable compared to the private viewpoint.