California and its generous voucher program and subsidies available through the Inflation Reduction Act provide a comfort zone for electric truck purchases that wouldn’t exist without them. How long will incentives be needed? It’s going to be awhile. “We definitely need the incentive money right now to help lower the cost,” Salim Youssefzadeh, CEO and founder of startup Truck-as-a-Service WattEV, told me. “Long term, we have to see prices of these trucks come down. We have to see prices of the charging equipment come down.” That requires economies of scale. At least 1,000 Class 8 electric trucks, he said. But...