A recent study by the Lawrence Berkeley National Laboratory (LBNL) has some generally good news for all of us who want to see greatly increased penetration of solar and wind power on the U.S. power grid. However, there are also a few challenges identified by LBNL, mostly related to grid management practices. See below for two graphics from the report, and also see the LBNL presentation, both of which highlight key impacts of higher "VRE" ("variable renewable energy") penetration through 2030. For intsance: