University of New Mexico UNM Digital Repository Geography ETDs Electronic Theses and Dissertations 6-25-2010 Suitability modeling and the location of utility-scale solar power plants in the southwestern United States Drew Ignizio Follow this and additional works at: https://digitalrepository.unm.edu/geog_etds Recommended Citation Ignizio, Drew. "Suitability modeling and the location of utility-scale solar power plants in the southwestern United States." (2010). https://digitalrepository.unm.edu/geog_etds/6 This Thesis is brought to you for free and open access by the Electronic Theses and Dissertations at UNM Digital Repository. It has been accepted for inclusion in Geography ETDs by an authorized administrator of UNM Digital Repository. For more information, please contact [email protected]. SUITABILITY MODELING AND THE LOCATION OF UTILITY-SCALE SOLAR POWER PLANTS IN THE SOUTHWESTERN UNITED STATES BY DREW A. IGNIZIO B.A., ANTHROPOLOGY UNIVERSITY OF NORTH CAROLINA-CHAPEL HILL, 2005 B.A., SPANISH UNIVERSITY OF NORTH CAROLINA-CHAPEL HILL, 2005 THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of Masters of Science Geography The University of New Mexico Albuquerque, New Mexico May, 2010 ©2010, Drew Ignizio iii ACKNOWLEDGEMENTS I would like to graciously thank my advisor and thesis chair, Dr. Paul Zandbergen, for all the time, advice, and valuable support that he has provided over the past two years—without his help and knowledge this project would not have been possible. Furthermore, the analysis completed in this project would not have been achievable had I not had the training and experience provided through my research position and the classes I had with Dr. Zandbergen. I would also like to thank my other committee members, Dr. Melinda Harm Benson and Dr. Chris Duvall for their support and contributions throughout the course of this research. Both of these faculty members have been very supportive of my research interests and have offered useful perspective and suggestions to help improve this thesis. Additionally, I would like to thank Dr. Maria Lane for the guidance and support that she provided me with in the course of this project—her insight and assistance were invaluable during the early stages of this research and I am very grateful to have had her contributions. To my parents: thanks for reading to me when I was little. iv SUITABILITY MODELING AND THE LOCATION OF UTILITY-SCALE SOLAR POWER PLANTS IN THE SOUTHWESTERN UNITED STATES BY DREW A. IGNIZIO ABSTRACT OF THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of Masters of Science Geography The University of New Mexico Albuquerque, New Mexico May, 2010 v SUITABILITY MODELING AND THE LOCATION OF UTILITY-SCALE SOLAR POWER PLANTS IN THE SOUTHWESTERN UNITED STATES By Drew A. Ignizio B.A., Anthropology, University of North Carolina-Chapel Hill, 2005 B.A., Spanish, University of North Carolina-Chapel Hill, 2005 M.S., Geography, University of New Mexico, 2010 ABSTRACT As states and regions have begun prioritizing renewable energy at the legislative level, solar energy has started to play a noticeably larger role in the energy portfolio of certain regions in the United States. Decision making concerning the siting of new solar facilities can be complicated, and GIS-based suitability modeling is often employed to determine ideal candidate sites. These suitability models seek to evaluate a comprehensive set of relevant criteria (such as insolation values, topography, access, land designation status, etc.), often at different weights, to produce a classified map of all potential sites that will facilitate decisions of site location. This research examines the nature and reliability of this type of suitability modeling by analyzing the extent to which those regions identified as ‘most suitable’ in a GIS model actually match up with the locations of existing and planned solar facilities. A suitability model was developed in ArcGIS based on examples from similar research, and compared against the actual locations of photovoltaic and concentrating solar facilities in the southwestern part of the United States. The topic of land ownership is also investigated to determine its relationship to the spatial distribution of solar facilities. vi The analysis indicated that although the locations of solar facilities fell mainly within those areas identified as highly suitable, this match was more noticeable for concentrating solar facilities than it was for photovoltaic facilities, indicating a need to develop separate models for these two types of facilities. Furthermore, while a high suitability classification seemed to be a prerequisite for solar facilities, the amount of highly suitable terrain in a state did not necessarily predict how many facilities would be present. Federally owned lands were also discovered to be preferable in regard to site locations. All of these results indicate the relevance of other non-spatial criteria as an explanation for the distribution of solar facilities, and the need to take into consideration the impact of such measures as state and local incentives and regulation, energy development efforts in other sectors, and other variables that have heretofore been absent in suitability models. vii TABLE OF CONTENTS LIST OF FIGURES ...........................................................................................................x LIST OF TABLES .......................................................................................................... xii CHAPTER 1 INTRODUCTION......................................................................................1 1.1 Background..............................................................................................................1 1.2 Goal..........................................................................................................................2 1.3 Objectives ................................................................................................................2 CHAPTER 2 LITERATURE REVIEW..........................................................................4 2.1 General Context .......................................................................................................4 2.2 Background of Renewables and Solar Energy.........................................................4 2.3 The Southwestern United States-The Region and the Role of Energy....................9 2.4 Geography and the Production and Transmission of Energy ................................15 2.5 Geography of Facility Location and Siting............................................................21 2.6 GIS and Suitability Modeling ................................................................................24 CHAPTER 3 RESEARCH DESIGN AND METHODOLOGY..................................31 3.1 Research Design.....................................................................................................31 3.2 Development of the Model - Data Processing Steps .............................................31 3.2.1 Data...............................................................................................................31 3.2.2 Model Overview ...........................................................................................33 3.2.3 Land Topography (Slope).............................................................................35 3.2.4 Incoming Solar Radiation (Insolation) Values .............................................38 3.2.5 Distance to Transmission Lines....................................................................40 3.2.6 Accessibility (Distance to Roads).................................................................43 viii 3.2.7 Weighted Summation of Input Layers..........................................................45 3.3 Ownership and Exclusion ......................................................................................45 3.4 Locations of Existing and Proposed Facilities.......................................................49 3.5 Overlaying Model Output with Actual Site Locations ..........................................53 CHAPTER 4 RESULTS AND DISCUSSION...............................................................55 4.1 Suitability Model Output .......................................................................................55 4.2 Locations of Utility-Scale Solar Facilities.............................................................59 4.3 Discussion of Findings...........................................................................................63 4.3.1 Validation of Model - Agreement between Locations and Model Output ...63 4.3.2 Land Ownership and the Distribution of Utility-Scale Solar Facilities........68 4.3.3 Socioeconomic Factors and Policy ...............................................................73 4.4 Suggestions for Future Suitability Models ............................................................82 CHAPTER 5 CONCLUSIONS.......................................................................................92 5.1 Evaluation of Research ..........................................................................................92 5.2 Limitations and Future Research ...........................................................................95 APPENDICES..................................................................................................................98 APPENDIX 1 - LIST OF UTILITY-SCALE SOLAR FACILITIES IN STUDY AREA ................................................................................................................................98