Power Scenario in Western US (IMAGE) University of California - Berkeley Caption One possible scenario for the electricity system in the Western US in 2026-29. Pie charts show the proportion of different types of energy sources generating power and flowing between load areas if there were a carbon tax of $70 per ton. According to the SWITCH model, such a tax could allow the West to reach a goal of 54 percent of 1990 emissions by 2030. Credit Daniel Kammen lab, UC Berkeley Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.