In two decades of experience with state renewable portfolio standards (RPSs), the United States has observed immense growth in renewable energy markets, initially in wind energy and more recently in solar power. During this time, RPSs have experienced considerable policy reinvention and increased diversity. Here, we explain how changes in RPS policy design features relate to different market outcomes. We develop a score for measuring RPS stringency and show that a one-point increase in RPS stringency leads to increases of 0.2%, 1% and 0.3% in renewable energy, solar generation and renewable energy capacity, respectively. Other important design features include resource eligibility, planning processes, cost recovery and geographical restrictions. These findings are then reaffirmed through 42 semi-structured phone interviews with experts in the field of RPS implementation from government agencies, including public utility commissions and state energy offices, electric utilities and various renewable energy firms and associations.
Subscribe to Journal
Get full journal access for 1 year
only $4.92 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
The code used to generate the statistical results in the present study, applicable to STATA 14, is available from the corresponding author upon request.
The data that support the results within this paper and other findings of this study are available from the corresponding author upon reasonable request.
Johnson, E. The cost of carbon dioxide abatement from state renewable portfolio standards. Resour. Energy Econ. 36, 332–350 (2014).
Barbose, G. et al. A retrospective analysis of benefits and impacts of U.S. renewable portfolio standards. Energy Policy 96, 645–660 (2016).
Yi, H. Clean energy policies and electricity sector carbon emissions in the U.S. states. Util. Policy 34, 19–29 (2015).
Hollingsworth, A. & Rudik, I. External Impacts of Local Energy Policy: The Case of Renewable Portfolio Standards. Social Science Research Network Working Paper (SSRN, 2018); https://ssrn.com/abstract=2697222
Bowen, W. B., Park, S. & Elvery, J. A. Empirical estimates of the influence of renewable energy portfolio standards on the green economies of states. Econ. Dev. Q. 27, 338–351 (2013).
Yi, H. Clean energy policies and green jobs: an evaluation of green jobs in U.S. metropolitan areas. Energy Policy 56, 644–652 (2013).
Barbose, G., Bird, L., Heeter, J., Flores, F. & Wiser, R. Costs and benefits of renewables portfolio standards in the United States. Renew. Sustain. Energy Rev. 52, 523–533 (2015).
Yin, H. & Powers, N. Do state renewable portfolio standards promote in-state renewable generation? Energy Policy 38, 1140–1149 (2010).
Delmas, M. & Montes-Sancho, M. US state policies for renewable energy: Context and effectiveness. Energy Policy 39, 2273–2278 (2011).
Alagappan, L., Orans, R. & Woo, C. What drives renewable energy development? Energy Policy 39, 5099–104 (2011).
Dong, C. Feed-in tariff vs. renewable portfolio standard: An empirical test of their relative effectiveness in promoting wind capacity development. Energy Policy 42, 476–85 (2012).
Fischlein, M. & Smith, T. M. Revisiting renewable portfolio standard effectiveness: policy design and outcome specification matter. Policy Sci. 46, 277–310 (2013).
Carley, S., Baldwin, E., MacLean, L. M. & Brass, J. N. Global expansion of renewable energy generation: an analysis of policy instruments. Environ. Resour. Econ. 68, 397–440 (2017).
Howlett, M. & Lejano, R. Tales from the crypt: the rise and fall (and re-birth?) of policy design studies. Adm. Soc. 45, 356–380 (2013).
Linder, S. & Peters, B. G. The study of policy instruments. Policy Curr. 2, 4–7 (1992). 2, 1.
Boborow, D. B. & Dryzek, J. S. Policy Analysis by Design (Univ. Pittsburgh Press, Pittsburgh, PA, 1987).
Wiser, R., Barbose, G. & Holt, E. Supporting solar power in renewable portfolio standards: experience from the United States. Energy Policy 39, 3894–3905 (2011).
Shrimali, G., Chan, G., Jenner, S., Groba, F. & Indvik, J. Evaluating renewable portfolio standards for in-state renewable deployment: Accounting for Policy heterogeneity. Econ. Energy Environ. Policy 4, 1–16 (2015).
Carley, S., Nicholson-Crotty, S. & Miller, C. Adoption, reinvention, and amendment of renewable portfolio standards in the American states. J. Public Policy 37, 1–28 (2016).
Nicholson-Crotty, S. & Carley, S. Effectiveness, implementation capacity, and policy diffusion: or, can we make that work for us? State Polit. Policy Q. 27, 78–97 (2015).
Barbose, G. U.S. Renewables Portfolio Standards: 2016 Annual Status Report (Lawrence Berkeley National Laboratory, accessed 28 September 2016); https://emp.lbl.gov/sites/all/files/lbnl-1005057.pdf
Crago, C. L. & Chernyakhovskiy, I. Are policy incentives for solar power effective? Evidence from residential installations in the Northeast. J. Environ. Econ. Manag. 81, 132–151 (2017).
Davies, L. L. Making sense of the rapidly evolving legal landscape of solar energy support regimes. KLRI J. Law Legis. 6, 81–142 (2016).
Sarzynski, A., Larrieu, J. & Shrimali, G. The impact of state financial incentives on market deployment of solar technology. Energy Policy 46, 550–557 (2012).
Buckman, G. The effectiveness of renewable portfolio standard banding and carve-outs in supporting high-cost types of renewable electricity. Energy Policy 39, 4105–4114 (2011).
Li, H. & Yi, H. Multilevel governance and deployment of solar PV panels in U.S. cities. Energy Policy 69, 19–27 (2014).
Heeter, J. & Bird, L. Including alternative resources in state renewable portfolio standards: current design and implementation experience. Energy Policy 61, 1388–1399 (2013).
Thoyre, A. Energy efficiency as a resource in state portfolio standards: lessons for more expansive policies. Energy Policy 86, 625–634 (2015).
Lee, D. K. & Duane, T. P. Putting the dormant commerce clause back to sleep: adapting the doctrine to support state renewable portfolio standards. Environ. Law 43, 295–364 (2013).
Hitaj, C. Wind power development in the United States. J. Environ. Econ. Manag. 65, 394–410 (2012).
Berry, T. & Jaccard, M. The renewable portfolio standard: design considerations and an implementation survey. Energy Policy 29, 263–277 (2001).
Cory, K. S. & Swezey, B. G. Renewable portfolio standards in the states: balancing goals and rules. Electr. J. 20, 21–32 (2007).
Davies, L. L. Evaluating RPS policy design: metrics, gaps, best practices, and paths to innovation. KLRI J. Law Legis. 4, 3–75 (2015).
Electricity Price by State and End-User, 1992–2014 (US Energy Information Administration, accessed 20 August 2016); http://www.eia.gov/electricity/data.cfm#electriccosts
Zirogiannis, N. & Tripodis, Y. Dynamic factor analysis for short panels: estimating performance trajectories for water utilities. Stat. Methods Appl. 27, 131–150 (2018).
State Energy Data System, 1960–2014 (Complete) (US Energy Information Administration, accessed 25 August 2016); http://www.eia.gov/electricity/data/state/
Natural Gas Prices, 1992–2014 (US Energy Information Administration, accessed 25 August 2016); https://www.eia.gov/dnav/ng/ng_pri_sum_dcu_nus_m.htm
Population and Housing Unit Estimates (US Census Bureau, accessed 23 August 2016); https://www.census.gov/programs-surveys/popest/data/tables.html
Regional Data: Annual Gross Domestic Product (GSP) by State (Bureau of Economic Analysis, accessed 23 August 2016); https://www.bea.gov/itable/iTable.cfm?ReqID=70&step=1#reqid=70&step=4&isuri=1&7003=200&7001=1200&7002=1&7090=70
Berry, W. D., Fording, R. C., Ringquist, E. J., Hanson, R. L. & Klarner, C. E. Measuring citizen and government ideology in the U.S. states: a re-appraisal. State Polit. Policy Q. 10, 117–135 (2010).
We acknowledge research assistance provided by J. Amadon, D. Baldwin, C. Davis, V. Luman, M. McKay, N. Mitchell, D. Olson, J. Williams, M. Williams and R. Woolston. Library research support was provided by S. Darais, R. McPhail and F. Murphy.
The authors declare no competing interests.
This research involved human subjects. It was approved with exempt status by the University of Utah, under protocol number 00063847. In accordance with this protocol, informed consent was provided by all study participants
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Carley, S., Davies, L.L., Spence, D.B. et al. Empirical evaluation of the stringency and design of renewable portfolio standards. Nat Energy 3, 754–763 (2018). https://doi.org/10.1038/s41560-018-0202-4
Energy Policy (2021)
Review of Policy Research (2021)
Renewable and Sustainable Energy Reviews (2021)
Energy Policy (2021)