Part 1: EV Charging Stations – Hardware

Many people don’t realize that the the first small scale electric cars were made all the way back in 1830! However, by the mid 1930’s they were abandoned for the most part. Now, almost 100 years later, new players like Tesla have rejuvenated the EV market. Picking up off the hybrid trend popularized by the Prius, a period of high gas prices, and a growing awareness of the environment, EVs have disrupted the car manufacturing market, forcing the public to accept an alternative to the gas standard. The ultimate goal of EV’s is to create a cleaner, more sustainable transport infrastructure, but to have a significant impact, scale is key.

Roughly 20% of all US emissions come from personal vehicles[1]. With EV’s representing only 0.22% [ChargePoint 2016 report] of the personal vehicle fleet in the US, there is clear room for improvement. However, for EV’s to hold a significant portion of the market, three things must be true and stay true. EV’s must: (1) have public appeal, (2) be cost competitive, and (3) have the infrastructure to accommodate the charging of large fleets in reasonable time periods. (1) & (2) have seen substantial progress over the last few years, but (3), charging infrastructure, is just beginning to ramp up on a large scale.

Before we dive in, some fundamentals in EV charging are necessary. EV’s are currently charged through either an AC charger or a DC charger. Car batteries run on DC, so AC chargers commonly utilize an inverter internal to the EV, while DC chargers will have a separate inverter specific to the charger to convert the electricity from the grid. For this reason, AC chargers are much more limited in their ability to charge at higher speeds. There are multiple levels (speeds) and standards (connection hardware) associated with these. The levels may vary by location. See Table 1 for a summary of the charger levels and standards.

Standards are important because chargers will only work if the charging standard of the charger matches the charging standard of the car. Generally, car manufacturers have chosen their charging standard according to the region. You cannot charge across different standards – it would be like trying to plug an American plug into a European outlet. Charging levels matter because they dictate the rate of charge. So when charging manufacturers look to develop a charger, they have to decide which standard(s) and which level(s) make the most sense for them to produce.

Charging Levels (power output) Typical Charge Time Charging Standard
Level 1 (Standard Plug) 8-15 hrs J1772
Level 2 (Menekkes) 3-8 hrs J1772, Tesla
Level 3 (DC Fast) ~1 hr CCS, CHAdeMO, GB/T, Tesla Supercharger
Level 3 (DC Ultra-Fast) <30 min CCS

Table 1: Charging levels and standards.

As seen in Table 1, there are currently 3 major standards in the DC fast charging market apart from Tesla, each associated with a region: CCS (North America and Europe), CHAdeMO (Japan), and GB/T (China). In late 2016, automaker powerhouses, BMW, Daimler, Ford, and the Volkswagen Group with Audi and Porsche, declared a joint venture to deploy 400 ultra-fast (350kW) CCS charging stations in Europe. While Europe joining America’s standard would seem to imply that CCS has won the battle for the fast charging standard of choice, China has the largest and fastest growing EV fleet in the world, so GB/T cannot be ruled out just yet.

Most charging manufacturers exist as more than just charging manufacturers. The spectrum ranges from large electrical companies like ABB who have a branch producing chargers, to specialized vertically integrated EV charging companies like ChargePoint, who handles everything from manufacturing to charging services and more. In general, however, charging manufacturers will offer a range of products to support the needs of various types of customers. Residential options include level 1 and level 2 chargers, while public charging stations require faster charge times and thus a level 3 charger. Manufacturers will also usually offer different variations of chargers to support different options for charging standards. Only ABB offers multiple standards and levels in a single charger.

Global EV Outlook 2017 reports that despite massive public charge station growth in 2016, there are only 212,000 public slow charger outlets and 110,000 public fast charger outlets for the 2 million EV’s in the world. That is a ratio of more than 6:1 EV to public outlets, implying that most EV owners are using private chargers. Inevitably, a successful solution will have a combination of residential, private/business, and public charger options, but I believe the most important component for large scale public adoption is a significant ultrafast charging infrastructure (>200kW). These could become synonymous with our current gas stations and relieve users (or autonomous cars) of the stress associated with long charge times and unavailability of charge stations. A future of large scale public charge stations means that a universal standard, agreed upon across car manufacturers and charger manufacturers, would be the most efficient path forward. However, a universal solution is likely years down the line, and in the meantime, the battle for charging standard will persist.

We must also consider the fact that to accommodate such a charging infrastructure, a corresponding electrical infrastructure upgrade will be required. Many charger manufacturers and software providers have created a workaround to inadequate infrastructure through demand management, basically allowing manual or automated setting of charge rates. By allowing a lower charge rate, property owners can increase the maximum number of operating chargers. However, this means that any time the number of people charging crosses a certain threshold, the chargers will not be acting at their nameplate capacity. Ideally, infrastructure would be upgraded to allow for charging of large fleets at full capacity, recognizing the full potential of EV’s.

On a forward looking note, it can be fun and useful to envision the future technologies of charging infrastructure. Some things we have started to see or can hope to see are induction chargers and portable chargers. Induction chargers aren’t a serious competitor at the moment, but ABB recently introduced a fast charging induction charger for public transportation that would be installed at select bus stops to quickly replenish the bus along its route. Portable chargers are another solution to the same problem. Instead of creating new lots for the charging of large EV’s, people are envisioning new ways to bring the charging to the vehicle. An exciting version of this would be drone delivered charging, where the vehicles would never even have to stop their route! Amazon has already been granted a patent for a roving drone that would charge personal EV’s as you drive. Of course for all of this to matter, EV’s still need to beat out hydrogen cars for the title of the preferred alternative to gas vehicles.

[1] https://www.ucsusa.org/clean-vehicles/car-emissions-and-global-warming#.

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