Greenhouse gas emissions could be cut by up to 90 percent in California and 57 percent in Texas if utilities invest in more energy storage facilities, according to a new study. Researchers at the University of Michigan, supported by colleagues at Ohio State University and North Carolina State University, found that such investments would be economically viable if proper policies are put in place by the government.
The study, titled The role of energy storage in deep decarbonization of electricity production, examines how energy storage can be effectively deployed to reduce energy curtailment, which in turn can help cut greenhouse gas emissions. Curtailment takes place when renewable energy facilities such as solar or wind power produce more energy than the electricity grid can use. As the authors write, “California, for instance, is experiencing days during which demand is too low to accommodate all of the solar energy that is available midday. This overgeneration-related renewable curtailment can be exacerbated by thermal generators having limited flexibility in how quickly they can adjust their production or how low their production levels can go.”
The results are impressive. If 60 gigawatts of renewable energy were deployed in California, made up of 40 gigawatts of solar and 20 gigawatts of wind power, the researchers estimate that greenhouse gases would drop by 72 percent. However, they also note that the curtailment rate would be 30 percent. If investments were made in energy storage to support the expansion of renewables, greenhouse gas emissions would fall by up to 90 percent and energy curtailment would drop to 9 percent. In Texas, the deployment of 60 gigawatts of renewables would cut greenhouse gases by 54 percent. This figure would increase to 57 percent with the inclusion of energy storage, which would cut curtailment from 3 percent to 0.3 percent.
On top of showing how sharply emissions could be reduced, the authors propose a way to encourage utilities to invest the substantial amounts of capital that would be needed to support the expansion of renewables with storage. Study co-author Maryam Arbabzadeh explains, “The cost of energy storage is very important. But there are some incentives we could use to make it attractive economically, one being an emissions tax.”
The biggest cut to greenhouse gas emissions projected by the authors was based on a carbon dioxide tax of $200 per ton.