The city of London needs to replace a whole lot of police cars, and it wants to do the right thing by the environment — which could be a huge opportunity for Tesla.

Sir Bernard Hogan-Howe, chief of London’s Metropolitan Police, spoke to Tesla CEO Elon Musk about testing his company’s cars as part of a wider push towards eco-friendly cop cars, it was revealed on Wednesday. Scotland Yard is spending £21 million ($26.5 million) on replacing 700 of its 4,000 cars by 2018, with the goal of deploying 250 alternative energy vehicles on London’s roads over the coming 12 months.

“These first vehicles are a stepping stone that will allow us to build the volume over time once we have the right technology and infrastructure in place,” Jiggs Bharij, head of the Metropolitan Police fleet services, told the Evening Standard.

The force is exploring deals with “nearly all” major car makers to roll out emission-cutting vehicles, but the police spoke directly with Musk about using his creation in everyday work.

The city is well-equipped for a Tesla-powered future. Source London, a city-wide electric charging network, provides 1,400 charging points, with plans to expand to 6,000 by 2018. Tesla also offers a small number of superchargers within central London. The extensive network has translated into real-world results: the force has conducted limited tests with a BMW i3 Range Extender, an electric car with a small gas-powered engine for when battery levels reach critical lows, and found success in several boroughs.

Another option currently being explored is hydrogen power. Five vehicles are expected to undergo testing near the five hydrogen fueling points around the city. Suzuki has been working with the force on hydrogen-powered scooters.

An LAPD-equipped Tesla. Tesla

London isn’t the first city to consider putting Teslas on the beat. The Los Angeles Police Department (LAPD) was reportedly testing out a Model S in October 2016, with police administrator Vartan Yegiyan hoping to get one in regular use by 2017. Before the force could undertake a widescale rollout, though, the price would have to come down quite a lot. The LAPD has suggested it could be a timescale of around three to five years before Teslas hit the road.

It may take a similar amount of time before Teslas come to London. The major driving force in cost reductions will be the Model 3, a $35,000 vehicle aimed at a mass market audience. Until then, there are possibly better ways for police forces to blow their budget than on kitted-out Model X cop cars.