Truckers say California’s ambitious plan for electric big rigs doesn’t match the state’s infrastructure, reports The Wall Street Journal.

State regulators want to phase out older trucks operating in California’s extensive business shuttling sea containers from ports to inland depots. That would require some 157,000 charging stations to serve the thousands of heavy-duty vehicles that operate in the pivotal leg of U.S. supply chains.

That charging infrastructure barely exists today, and the environmental requirements and electrical grid demands behind the power sources suggest the state has an uphill climb to fill the gap. 

The conflict highlights the challenges that other states will face as they try to push heavily polluting freight operations toward clean fuels. California regulators say the phase-out plan is aimed at creating a market for the charging infrastructure, with hopes that private industry will plug into the plan.