Angeles is seen behind an electricity pylon through the morning marine layer in Los Angeles, California, U.S., August 20, 2019. REUTERS/Lucy Nicholson Dec 17 (Reuters) - The organization responsible for North American electric reliability said on Friday that several parts of the United States could face energy shortfalls during the next decade due to insufficient power generation resources. Specifically, the North American Electric Reliability Corp (NERC) said in a study that there is a high probability of insufficient resources and energy to serve electricity demand as early as summer 2022 in many parts of the Western Interconnection, which includes California and other states in the U.S. West. The study projected that California, parts of the northwestern and southwestern United States and the Midcontinent Independent System Operator (MISO) areas could experience capacity shortfalls and periods of insufficient energy due to declining reserve margins and generator retirements over the next 10 years. Extreme weather conditions and performance issues associated with some inverter-based resources, such as solar, wind and new battery or hybrid generation, may also have a potential negative impact on reliability, NERC said. The situation calls for focus on energy assurance and coordination between the natural gas and electricity industries to ensure reliability during this time of grid transition, NERC said. In addition, the study found that natural gas infrastructure that supports electricity generation in New England, California, and the southwestern United States is susceptible to disruptions that can affect winter reliability.