The city has proposed paying $3.4 billion. PG&E, however, is expected to argue that the assets are worth at least $20 billion, a figure the city’s attorney has called “absurdly inflated.”

The competing estimates also reflect disagreements about what a takeover would cost. San Francisco’s proposed price does not include certain expenses city officials say the city would have to cover separately, including building a new station to receive power and deliver it to the grid. PG&E’s valuation includes those larger costs.

The dispute comes amid concerns about service reliability. San Francisco says it has experienced 40 power outages so far this year and has urged state regulators to investigate what city leaders describe as problems with PG&E’s performance. City Attorney David Chiu has said the city experiences about one major outage a week.

PG&E CEO Patti Poppe has pushed back on the city’s assessment, saying last week that the utility has had less outage time this year. She has also argued that San Francisco is underestimating the cost of taking over the system and undervaluing the company’s assets. Poppe warned that PG&E would fight the effort, saying she could imagine the company’s trucks leaving the city and not returning. Chiu said the city would likely rehire many of the workers.

The California Public Utilities Commission is working to determine a “fair and just” value for a possible sale. That process will take time, and the disagreement could ultimately be resolved in court. For residents, the valuation fight will help determine whether a public takeover is financially feasible—and who would bear the costs of maintaining and delivering electricity.