The Menlo Park, Calif., Fire District has unveiled an all-electric fire engine, hosting a demonstration of the All Electric Rosenbauer Concept Fire Truck this week.

Since fire engines only travel short distances before returning to their home base, and most emergencies last 30 minutes or less, electric motors make sense, according to the fire district. Ninety percent of all emergencies are short duration incidents — such as medical incidents, vehicle accidents, alarm soundings, and other calls — and the engine can be shut down once it arrives to the incident.

In comparison to diesel engines, electric vehicles don’t emit carcinogens, have fewer moving parts for less wear and tear, and have less maintenance and downtime, according to the fire district.

The EV fire truck is a concept five years in the making and is not yet ready for use. Menlo Park’s frontline firefighters are working with Rosenbauer to test the vehicle before purchasing it, The Mercury News reported. The prototype costs $5 million, and a working model would cost $1.2 million.