AN ANALYSIS OF THE FEASIBILITY AND ENVIRONMENTAL IMPACT OF INCORPORATING CLEAN ENERGY INTO AN ISLANDED MICROGRID IN SIERRA LEONE

Clarity Project is a fine jewelry company and social enterprise that recently began mining diamonds in Sierra Leone as part of its mission to improve the quality of life of artisanal miners in West African communities. This has presented a new challenge to the company: the site of Clarity Project’s new mining compound is distant from the country’s modest electric grid, leaving Clarity Project to procure its own electric power. The purpose of this project is to determine Clarity Project’s electricity needs, analyze its alternatives for meeting those needs, and evaluate the costs and environmental impacts of those alternatives. Using data obtained on site in Sierra Leone and meteorological data from NASA, we developed a model that predicts the load profile of the mining compound, forecasts the expected amount and temporal availability of electricity from photovoltaic arrays on site, and projects the use of diesel generators and battery storage to supplement the solar power. The model then calculates the present value of the capital and operating expenses for the microgrid as well as the carbon dioxide emissions associated with generating electricity for the compound. Our analysis has determined that (1) the least expensive option, based on capital expenses and operating expenses discounted to present value, would be to rely solely on diesel generators; (2) the cost of relying solely on renewable energy during Sierra Leone’s dry season would be approximately double the all-diesel option over a five-year time horizon and about 60 percent greater over a 25-year time horizon (and the availability of renewable energy falls significantly during the rainy season); and (3) incorporating solar power and battery storage, while more expensive, would allow Clarity Project to avoid emitting nearly 20 metric tonnes of carbon dioxide per year.