Mercedes to Launch EV Charging Network. Is the Grid Ready?

The largest manufacturer-sanctioned charging network in the U.S. by far is Tesla's Superchargers. There are currently more than 1,400 Supercharger stations in the United States, with 7,000 more individual plug-ins, and Tesla has been building them for the past decade.

Mercedes will be partnering with ChargePoint, an existing manufacturer of EV charging solutions. These include public chargers and home charging kits. ChargePoint has installed and operated more than 30,000 accessible charging stations and had partnered with Mercedes in the past, as well as with other brands like Lexus, Toyota, Volkswagen and Volvo.

"Charge point is what actually got my attention," Fernandes says, "because they do bring a level of expertise and know-how to the project. Having ChargePoint involved in the process is almost certainly going to help." But automakers like Mercedes are still playing catch-up.

Fernandes says he thinks Mercedes' aggressive plan is necessary but optimistic. He also says adding this many new EV chargers could result in a significant load on the power grid.

"Especially because they're going for a fast-charging type system," he says. "And right now, there are a lot of big loads trying to connect to the [electrical] grids in North America. They're going to have to be studied. There could be upgrades [on the electrical grids] required, and it's really those study timelines that are going to take some time."

But there's still the question of whether the grid can even handle this many new EVs at all. A study by researchers at Stanford University published in the journal Nature in September 2022 says the huge influx of EVs will help reduce emissions in the United States, but their demand for charging may challenge electricity grid operations. By 2035, the study found, EV growth could increase electricity demand by as much as 25 percent.

The new Mercedes stations will be based on existing hardware, the ChargePoint Express Plus DC Fast Charger. This charging station includes up to four power plugs per unit, and can send up to 150 kiloWatts per port on power lines ranging from 100 to 1,000 volts. In the U.S., chargers are most likely to be installed on either a 240- or a 480-volt line. Mid-size EVs such as the Mercedes EQE or the Tesla Model S long range come with battery capacities of about 100 kW hours.

With all those numbers in mind, the ChargePoint stations should be able to charge these sedan batteries from mostly depleted up to 50 percent capacity in about 20 minutes, but the charging power will still have to be pulled from the grid.

Mercedes and ChargePoint do plan to include integrated solar panels on charging hubs that have space for a roof. These panels will supply energy for things like lighting. And in the press statement, Mercedes-Benz said the two companies will negotiate with energy suppliers and give preference to sustainable sources like solar power and wind energy where applicable.

Meanwhile, the Stanford study researchers say one possible way to reduce the pull on the grid could be to have drivers of EVs shift their charging times. Currently most drivers charge their cars at home overnight, according to the study. If, instead, they charged during the day at public charging stations at work for instance, the U.S. would need less electrical generating capacity and storage.

The Mercedes-Benz charging stations will mostly be located near motorways, major intersections and in metropolitan areas, though there's no indication they will be convenient to overnight charging like the Stanford study suggests. But Mercedes says the stations will be equipped with surveillance cameras and other measures for safe charging at all times.

The stations will be open to all EVs, too, but Mercedes-Benz owners will have access to exclusive features, including hands-free payment options and the ability to pre-schedule particular charging hubs. The hubs also will have built-in data contacts that interface with the Mercedes EV's charging ports to allow drivers to automatically charge the electricity fees to their preferred payment methods.

"[These options] contribute to the experience, right? I think for Mercedes, it's commercially a very good idea," Fernandes says. "The biggest thing really is [energy] distribution. When you're building out the charging infrastructure to this level, what are those grid usage profiles going to look like? When you look at the market dynamics, getting into supply chain and system costs, it's really global EVs that are driving everything right now."