A Time Series Sustainability Assessment of a Partial Energy Portfolio Transition

Jacob Hale,Suzanna Long

doi:10.3390/en14010141

Abstract

Energy portfolios are overwhelmingly dependent on fossil fuel resources that perpetuate the consequences associated with climate change. Therefore, it is imperative to transition to more renewable alternatives to limit further harm to the environment. This study presents a univariate time series prediction model that evaluates sustainability outcomes of partial energy transitions. Future electricity generation at the state-level is predicted using exponential smoothing and autoregressive integrated moving average (ARIMA). The best prediction results are then used as an input for a sustainability assessment of a proposed transition by calculating carbon, water, land, and cost footprints. Missouri, USA was selected as a model testbed due to its dependence on coal. Of the time series methods, ARIMA exhibited the best performance and was used to predict annual electricity generation over a 10-year period. The proposed transition consisted of a one-percent annual decrease of coal’s portfolio share to be replaced with an equal share of solar and wind supply. The sustainability outcomes of the transition demonstrate decreases in carbon and water footprints but increases in land and cost footprints. Decision makers can use the results presented here to better inform strategic provisioning of critical resources in the context of proposed energy transitions.

Highlights

Fossil fuel resources provide a majority of the world’s energy and subsequent carbon dioxide emissions [1,2]
Using the Forecast Library in r, simple exponential smoothing and autoregressive integrated moving average (ARIMA) models were fit to the annual state-level electricity generation dataset
Global energy portfolios are dependent on fossil fuel resources

Summary

Introduction

Fossil fuel resources provide a majority of the world’s energy and subsequent carbon dioxide emissions [1,2]. In 1990, fossil fuels made up more than eighty-six percent of the total primary energy supply of the United States and its combustion resulted in more than four thousand eight hundred megatons of carbon dioxide emissions. By 2015, energy demands increased by almost an additional thirteen percent with carbon dioxide emissions increasing by more than an additional two and a half percent. During this time, renewables increased by less than two percent. When excluding biofuels and waste-to-energy sources, this increase is less than one percent These findings demonstrate that portfolios are shifting, but not toward renewables resulting in an increase in already high carbon dioxide emissions

Methods

Results

Discussion

Conclusion