|
|
| Fig. 1: Example of Residential PV. (Source: Wikimedia Commons) |
California has become the pioneering state in the U.S. for attacking the fossil fuel problem that plagues the current climate. With the creation of the Renewable Portfolio Standard (RPS), California put into legislation a plan to increase its renewable energy created electricity. [1] The RPS forces the electric utility companies to get their energy from renewable types, whether it be wind, solar, geothermal, or any other renewable energy other than large hydropower plants. Renewable energy credit (REC) are then awarded for using the renewable energy for electricity production. [1] RECs allow the utilities to prove compliance with the policy, with one REC received for every megawatt hour (MWh) produced through renewable energy. As of December 31, 2020 the policy states that 33% of the retail energy sales must come from renewable energy sources. Recently in 2015 California's Governor, Jerry Brown, set forth a new target for the state to reach 50% renewable energy production by 2030. The target is a bold one, that will need action statewide to be achieved. The Clean Energy and Pollution Reduction Act of 2015 set the target into legislation.
The current landscape in California's renewable energy portfolio is dominated by wind and solar. These two have combined to see the largest growth in the past decade. [2] Recently a study into regulated utilities showed a portfolio of 35% geothermal, 34% wind, and 12% biomass. The RPS program put forth by California has led to the highest growth in the wind and solar sectors. Their combined generation grew from 2.4% in 2002 to 11.7% in 2014. [2] Overall growth rates reached 19.7% in 2013, due in large part to on-shore wind and solar PV installation; an example of solar PV in use can be seen predominantly on residential buildings (See Fig. 1). Those percentages have continued to grow now into 2018. The need to reach the targets marks set for 2030 have pushed installations forward to increase the overall size of the renewable energy portfolio in California.
One of the largest barriers to California reaching its RPS is curtailment. The basic definition of curtailment is reducing the output of renewable energy sources, mostly wind and solar energy, from its highest possible capacity. The term over-generation generally follows suit with curtailment, because the over-generation of resources during specific times of the day is what causes curtailment to happen. For instance, during a low load period of the day, around midday typically, electricity producers such as coal or natural gas need to keep running. If a solar field or a wind farm is producing at a high level, excess amounts of electricity will be produced with no end-users to consume it. In a sense, this electricity is wasted. Curtailment then happens and the renewable energy producers stop producing. [3] Meeting the RPS put forth by the state becomes a problem then as non-renewable energy takes a backseat to greenhouse gas producing fossil fuels. The exponential rise in solar PV now causes a large issue in the form of curtailment. [3] A report by E3 in 2015 stated under a 50 percent RPS with very large amounts of solar PV development, an exponential increase in curtailment could also lead to a significant rate increase as there would need to be a major overbuild of renewable resources to meet the higher RPS target. As of right now, curtailment provides the largest barrier to California meeting its target of 50% renewable energy production by 2030.
The aggressive target set in 2015 to reach a RPS of 50% by 2030 has driven the urgency in California to implement more installations of renewable energy. Many critics believe the target is not reachable by 2030, and attempting to do so will create more harm than good. As mentioned, many barriers stand in the path between stating the target, and actually reaching it. Curtailment remains the immediate barrier to renewable energy's flourishment in California. If a policy can be put into place to deal with it, the feasibility of reaching 50% by 2030 seems much more realistic.
© Erik Miller. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] F. Mormann, D. Reicher and V. Hanna, "A Tale of Three Markets: Comparing the Renewable Energy Experiences of California, Texas, and Germany," Stanf. Environ. Law J. 35, 55 (2016).
[2] C. N. Allen, "Untapped Renewable Energy Potential: Lessons for Reforming Virginia's Renewable Energy Portfolio Standard From Texas and California," Va. Environ. Law J. 35, 117 (2016).
[3] R. Golden and B. Paulos, "Curtailment of Renewable Energy in California and Beyond," Electric. J. 28, 36 (2015).
