Environmental Implications of Renewable Distributed Generation Technologies in Rural Electrification

Abstract

Customer choices and competition have led the electric utilities to undergo major regulatory and technological changes while power sector reform continues. A part of this change also originates from the rapid emergence of viable small-scale distributed generation (DG) sources that are highly competitive with grid-delivered electricity in the isolated areas. In this article, the cost-effectiveness of renewable DG sources (i.e., photovoltaics, small-scale wind turbines, and biomass gasifiers) are assessed and compared with centralized generation for the case of a rural and isolated island in the western state of India using the Hybrid Optimization Model for Electric Renewables (HOMER), developed and provided by the U.S. National Renewable Energy Laboratory (NREL). The model identifies a least cost set of various DG and centralized grid capacities and ranks them based on a life cycle cost. The adoption of DG technologies (especially wind and biomass gasifiers) provide no-regret options with significant CO₂ emission mitigation potential when operated under net-metering scheme.

Keywords:

• biomass gasifier
• CO₂ emissions
• distributed generation (DG)
• emissions mitigation
• wind power

Acknowledgment

The authors gratefully acknowledge the financial support from the North Dakota Experimental Program to Stimulate Competitive Research and the National Science Foundation for support to Dr. Michael Mann under Grant #0093923. However, only we are responsible for the views expressed in this paper. The authors go beyond the Hansen and Bower study; however, the analysis in this paper was possible with the majority of primary data published in the Hansen and Bower study.

Notes

¹The levelized cost of energy (COE) is the average cost of producing electricity.

²For a gasifier engine operated on 100% producer gas.

³The Weibull shape factor is a measure of the distribution of wind speeds over the year.

⁴The clearness index, which is a fraction of the solar radiation transmitted through the atmosphere to reach the earth's surface, is a measure of the clearness of the atmosphere and generally varies from 0 to 1. The clearness index has a high value under clear, sunny conditions and a low value under cloudy conditions (NREL, 2005).

⁵The marginal abatement cost of CO₂ (MACC) is calculated as follows:

where TC ⁰ is the present value of total cost corresponding to the BAU case, TC ^d is the present value of total cost corresponding to the distributed generation case, E _t ⁰ is the CO₂ emissions in year t corresponding to the BAU case, E _t ^d is CO₂ emissions in year t corresponding to the distributed generation case, r is the discount rate, and T is the life of the project.