San Francisco has reached a key milestone in its effort to expand public power after the city’s Planning Commission unanimously certified the final environmental impact report for a proposed acquisition of Pacific Gas & Electric Co.’s electric distribution assets serving the city.

The report, required under the California Environmental Quality Act, evaluates the environmental effects of purchasing PG&E’s local electric infrastructure and the work needed to separate San Francisco’s electric grid from the utility’s broader system, the Public Utilities Commission said.

City officials said certification of the report allows the project to move into the next phase, including proceedings before the California Public Utilities Commission to determine the fair market value of the assets and evaluate a potential purchase.

The San Francisco Public Utilities Commission estimates the assets are worth about $3.4 billion.

If approved, the acquisition would be financed through revenue bonds repaid by electric rates rather than the city’s general fund or tax revenue.

The SFPUC currently supplies about 75% of the electricity used in San Francisco through its Hetch Hetchy Power and CleanPowerSF programs, but does not own the local electric grid.

City officials said acquiring the system would allow the city to provide electricity directly to all San Francisco customers while PG&E would continue serving areas outside the city.