Comparison of Technological Options for Distributed Generation-Combined Heat and Power in Rajasthan State of India

Distributed generation (DG) of electricity is expected to become more important in the future electricity generation system. This paper reviews the different technological options available for DG. DG offers a number of potential benefits. The ability to use the waste heat from fuel-operated DG, known as combined heat and power (CHP), offers both reduced costs and significant reductions of CO2 emissions. The overall efficiency of DG-CHP system can approach 90 percent, a significant improvement over the 30 to 35 percent electric grid efficiency and 50 to 90 percent industrial boiler efficiency when separate production is used. The costs of generation of electricity from six key DG-CHP technologies; gas engines, diesel engines, biodiesel CI engines, microturbines, gas turbines, and fuel cells, are calculated. The cost of generation is dependent on the load factor and the discount rate. It is found that annualized life cycle cost (ALCC) of the DG-CHP technologies is approximately half that of the DG technologies without CHP. Considering the ALCC of different DG-CHP technologies, the gas I.C. engine CHP is the most effective for most of the cases but biodiesel CI engine CHP seems to be a promising DG-CHP technology in near future for Rajasthan state due to renewable nature of the fuel. 1. Introduction In centralized generation(CG), electricity is generated in large remote plants. Power must then be transported over long distances at high voltage before it can be used. Distributed generation (DG) can be defined as electric power generation within distribution networks or on the customer side of the network [1]. DG is referred to as the use of small, modular power generation at or near the point of consumption irrespective of size, technology, or fuel used—both off-grid and on-grid as an alternative to large power generation and electricity transport over long distances [2]. The performance of the small power technologies (i.e., reciprocating engine and gas turbine) has improved remarkably over the last decade. In the last decade, technological innovations and a changing economic and regulatory environment have resulted in a renewed interest for distributed generation [3]. This is confirmed by the five major factors that contribute to this evolution; these are developments in distributed generation technologies, constraints on the construction of new transmission lines, increased customer demand for highly reliable electricity, the electricity market liberalization, and concerns about climate change [4]. This has aroused the interest of operators, regulators,