An approach to the quantification of the benefits of distributed generation

Scope of study. The quantification of the technical benefits of distributed generation (DG) has been considered in this work. The objective of this study is to propose an approach to quantify the benefits of DG when introduced into existing utility distribution networks. A set of indices, namely, voltage profile improvement index (VPII), line loss reduction index (LLRI), environmental impact reduction index (EIRI), and distributed generation benefit index (BI) are developed and proposed to quantify the benefits of DG.; Findings and conclusions. Among the many DG technologies, wind turbine generation (WTG), microturbine systems, photovoltaic systems (PV), and fuel cell systems are considered. The power output of WTG and PV systems are modeled in terms of probability density functions while the power outputs of microturbines and fuel cells are schedulable and are expressed in terms of fuel flow rates. To evaluate and quantify the benefits of DG, suitable mathematical models for DG technologies are employed along with distribution system models and power flow calculations to arrive at a set of indices to quantify the benefits. The basic concept behind the proposed VPII, LLRI, and EIRI is to compare and calculate the ratio of a measure of the attribute in question with and without the employment of DG for the same loads at the different buses. With the employment of DG, the simulation results clearly show that voltage profile is improved and line losses and pollutant emissions are reduced. VPII, LLRI, and EIRI are sensitive to the ratings of DG as expected. Generally, VPII goes up and EIRI goes down as DG rating goes up. However, this trend is not always applicable to line loss reduction because the amount of reduction can decrease as DG rating goes up in some cases. The location of DG is also significant to both voltage profile improvement and line loss reduction. The operating power factor of DG also plays a major role in determining the benefits of DG. The benefit indices proposed in this work can assist in identifying the best locations and ratings for DG installations to maximize the technical benefits.