Plans for a public power agency and the renewable energy projects that could sprout with it appear to have scrambled politics in Sonoma County.

Scott Bartley was elected mayor of Santa Rosa by his council colleagues Tuesday night in a split vote decided by newcomer Erin Carlstrom, who then cast the deciding vote for herself as vice mayor.

Former Santa Rosa Councilwoman Veronica Jacobi plans to challenge Sonoma County Supervisor Efren Carrillo for his west county seat in June’s election. Jacobi, 53, a mechanical engineer and energy management consultant, served one, four-year term on the City Council before being ousted in the 2010 election when a slate of pro-business candidates shifted the council majority.

Wal-Mart’s expansion of its Rohnert Park store hit a bump Thursday when a Sonoma County judge ruled more work is needed on noise and parking issues.

Sonoma County’s urban-growth boundaries have guided development toward urban areas and away from open space. Amanda Bornstein and Dennis Rosatti, who work with the Greenbelt Alliance and Sonoma County Conservation Action, say residents must stay engaged to protect open space and farmland for future generations.