Modeling by the Natural Resources Defense Council finds that a 50 percent renewable portfolio standard will improve the health of Arizonans, in addition to driving local economic investments in solar power, reducing electricity bills, and creating 16,000 clean energy jobs. A 50 percent renewable portfolio standard (RPS) would require investor-owned utilities in Arizona to supply half of their customers’ electricity demand from renewable sources, like solar and wind energy, by 2030. This is the standard set by Proposition 127, which is on the November general election ballot and would affect Arizona Public Service (APS) and other utilities regulated by the Arizona Corporation Commission (ACC).
Our modeling finds that a stronger RPS would reduce harmful air pollution spewing from Arizona’s power plants: nitrogen oxides (NOX) emissions fall by 51 percent, sulfur dioxide (SO2) emissions by 13 percent, and carbon dioxide (CO2) emissions by 34 percent in 2030, compared to 2017 levels.
Less NOX and SO2 means less soot and smog in the air and healthier communities. Reductions in these air pollutants are tied to fewer asthma attacks, fewer ER visits and hospitalizations, and even fewer premature deaths. In fact, the reduction in power-related NOX and SO2 emissions from a 50 percent RPS are equal to $28-62 million in health benefits for Arizonans in 2030 alone.
Our Inputs, Assumptions, and Modeling
The Natural Resources Defense Council (NRDC), NextGen Policy Center, and GridLab worked with energy consultant ICF to model and analyze the energy and economic impacts of strengthened RPS targets across the southwest using ICF’s Integrated Planning Model (IPM®). IPM is a detailed model of the electric power system routinely used by the electricity industry and regulators, including the U.S. Environmental Protection Agency, to assess the effects of environmental regulations or policies. It integrates extensive information on power capacity and generation, technology performance, transmission, energy demand, electricity and fuel prices, energy-related policies, and other factors. IPM then determines the most cost-effective way to meet electricity needs based on its detailed representation of the U.S. electricity system. It can build new power plants, retire existing plants, or ramp them up and down to meet demand in the least-cost way.
All inputs and assumptions were developed by NRDC, NextGen Policy Center, and GridLab, and are based on publicly-available information from various branches of the U.S. Department of Energy. For more details and links to the sources for our inputs and assumptions, read this blog.
We used this modeling to examine the effects of strengthening renewable energy standards across the Southwest. Arizona is not the only state in the interconnected Western grid that is thinking about making strong commitments to renewable energy, and resource decisions in one state can impact others. To capture this, our modeling includes not just the 50 percent RPS in Arizona, but also stronger renewable portfolio standards that apply to utilities in Colorado, Nevada, and New Mexico. We conservatively applied a 25 percent by 2025 RPS for Arizona’s Salt River Project, a large utility not regulated by the ACC or subject to Prop. 127, but which is focusing more on renewable energy.
Better Air Quality, Better Public Health
The Phoenix area has the country’s 8th worst ozone pollution problem and is among the worst-20 cities for short-term particulate pollution. Modeling shows that Arizona would have cleaner and healthier air in the future under a 50 percent RPS. Specifically, nitrogen oxides (NOX) and sulfur dioxide (SO2) emissions from the state’s power sector would fall by 51 percent and 13 percent, respectively, compared to 2017 levels. These pollutants are emitted when we burn fossil fuels—like coal and gas—to generate electricity. Coal-fired power plants are a significant source of both NOX and SO2, while gas plants produce NOX and other gases.
NOX refers to a family of chemicals that contribute to smog and can have serious health effects, especially for infants and children. Studies conducted by federal and state agencies have shown it can worsen allergies and aggravate respiratory issues, especially for children. That results in more coughing, wheezing, difficulty breathing, asthma attacks, and increased ER visits related to these respiratory problems or even premature death. NOX has even been linked to decreased lung function growth in children, meaning children who grow up with long-term exposure to NOX have smaller lungs than children without it.
SO2 has been shown to have similar negative health impacts, especially for the elderly and children or adults with asthma. Sulfur dioxide irritates and inflames our noses, throats, and airways, which can make breathing difficult or painful, especially for those with pre-existing cardiovascular and pulmonary diseases (like asthma). It can also worsen existing heart disease.
Both NOX and SO2 also interact with other gases and dust in the atmosphere to help create particulate matter (PM) and ground-level (or “bad”) ozone. Particulate matter is too small for us to see with the naked eye, but it is far from harmless. Small enough to inhale, it wreaks havoc once it is in our lungs and bloodstream. Exposure to PM has been associated with more premature deaths, as well as increased emergency room visits and hospital admissions for lung and heart problems. Breathing ozone is linked to similar health problems and can also have serious harmful effects on our ecosystems and sensitive lands, like forests, national parks, wildlife refuges, and wilderness areas.
Cutting the NOX and SO2 coming out of smokestacks will improve public health in Arizona, reducing asthma attacks, hospitalizations, ER visits, and even premature deaths.[VP4] Using EPA benefit-per-ton estimates, the modeled reductions in these pollutants are worth between $28 million and $63 million in monetized public health benefits for Arizonans in 2030 alone.
Minimizing Arizona’s Deadly Summer Days
A stronger clean energy standard would also reduce the state’s carbon footprint. Carbon dioxide (CO2) is the largest source of climate-warming greenhouse gas emissions in the U.S. and globally, and governments around the world are taking actions to reduce greenhouse gas emissions to safe levels. With a 50 percent RPS, emissions from the state’s power plants in 2030 would be 34 percent lower than they are today. This renewable energy future is also significantly cleaner than the gas-heavy future the state’s investor-owned utilities want. As part of our analysis, we also modeled a scenario where APS and Tucson Electric Power get to build all the new gas plants they requested in their long-term plans. In this gas-heavy case, annual CO2 emissions are 25 percent higher in 2030 than in the 50 percent RPS case.
Arizona has already begun to see the impacts of climate change: the U.S. EPA estimates that the state has already warmed by 2 degrees F and a recent study by the Weather Channel concluded that Phoenix had seen the largest increase in temperatures over the last 50 years among all major U.S. cities. Temperatures across the state are also projected to continue to increase: a 2016 study projected that Phoenix’s summer weather will be, on average, 3 to 5 degrees hotter by 2050 without more aggressive climate action. This would add about an extra month of 100-plus-degree days to Phoenix’s current average of 110 extreme-temperature days per year. It would also increase the likelihood of drought. Up to 20 percent of the Colorado River, the main source of drinking water and irrigation for Arizona, could dry up by 2050. Researchers say rural Arizonans and those working in agriculture would be the first to feel these impacts.
Arizonans know how to live with heat, but they also know these extremely hot days negatively affect everyone’s health. Maricopa County reported 130 heat-associated deaths in 2016 and that number will continue to rise without coordinated action to reduce climate pollution.
Prop. 127 is the right choice for health, the economy, and future generations.
In addition to the economic benefits of using Arizona’s most plentiful resource—the sun, cutting down on harmful air pollution from electric utilities in Arizona is a step in the right direction to protect Arizonans’ health and preserve the state’s beauty for future generations.