Case Studies of Distributed Generation Projects With Microturbines in Brazil

Microturbines have showed good perspectives for the distributed generation of the electricity in low capacity range, because they have high reliability and simple design (high potential for a cheap manufacture and in large scale). Besides, this technology must have a great application in systems of cogeneration of the public service (malls, hotel, hospital, etc.) and in the distributed generation of the electricity in the developing countries in order to get a reliable operation system, in a range of power compatible with the isolated communities. In Brazil, The Thermal Systems Study Group (NEST) of Federal University of Itajuba´ (UNIFEI) sponsored by The Energy Company of Minas Gerais (CEMIG), are developing a project of experimental valuation of the system with microturbines for electricity generation fueled with natural gas and diesel. The objective of this paper is to show an economic evaluation which presents the generation costs and the payback period with the Capstone 30 kW natural gas microturbines business in three cases: microturbines operating on base load in gas station, microturbines operating on peak shave in the industry and a microturbine cogeneration system operating in the residential segment. It was considered the cost of microturbines at this moment and the projection for the future, as well as the cost of electricity and natural gas in Brazil. An economical analysis was carried out for different variables involved and the results show the Capstone 30 kW natural gas microturbines business are feasible firstly in cogeneration cases which is possible to get until 3 years of payback period. Besides, the return on the investment have shown improvements with the incentive of the natural gas distributing companies and with the rises in the electricity price of Brazilian utilities.