The Evolution of EV charging load in North America and why data from 5 years ago has expired

August 20, 2019

Would you make investments in the stock market today based on information from 5 years ago? Of course you wouldn’t, companies rise and fall, new technology disrupts markets, and trends change. This is exactly why utility companies shouldn’t be relying on EV charging data that’s 5 or more years old, it’s now outdated. In 2014 there were 558,953 electric vehicles sold in the US, however the majority were Hybrids that didn’t plugin (HEV). Plug-in hybrids (PHEV) and battery electric vehicles (BEV) combined only represented 20.9% of total EV sales. Compare that to sales figures for 2018 where there was a total of 653,765 EVs sold with 50.2% of them being a PHEV or BEV. This change in vehicle market share may make it seem like the number of EVs that will affect the grid are lower than they actually are. Changes in EV technology, such as larger battery capacity and faster charging will also increase the impact that EVs will have on the grid as today’s vehicles are charging at higher power levels, and are consuming more electricity than ever before. These are just some of the factors utilities need to consider when reviewing “expired” EV data.

Changes in the EV ecosystem

As mentioned above, one of the biggest changes to the EV ecosystem is the transition from Hybrid and Plug-in hybrid models to fully electric (BEV) models. This is an important trend as these are the types of EVs which affect distribution grids the most. When looking at EV charging data from 2014 or earlier there will be significant information missing as 4 out of the top 5 best-selling plug-in electric vehicles (PEV) of 2019 thus far weren’t in production yet, meaning that none of them would have been included in any of that data. Also, there has been a significant rise in the amount of long-range BEVs being sold, specifically the Tesla Model 3 which accounts for 46% of 2019’s plug-in electric sales for the US. This is important because long-range BEVs charge very differently than other EVs and pose the greatest risk to distribution infrastructure. 

BEVs are game changers and they, themselves have changed

In 2017 SEPA released a case study, Integrated DER Planning, that exposed the destructive potential of EVs to local transformers. During the study it was predicted that 17 percent (12,000) of the transformers in the Sacramento Municipal Utility District (SMUD) service territory may need to be replaced by 2030. While this is a significant conclusion the outcome might actually be worse as this study would not have included the Tesla Model 3, which again has accounted for 46% of 2019 US PEV sales. While this study provides important insights and critical information, utilities should be supplementing it with new data to fully grasp today’s situation. Not only are there more BEVs on the roads today, but they aren’t the same vehicles that were on the road before. The capacity of these batteries are much higher, which means they require more power to charge. A 2014 Nissan Leaf would draw 3.3 kW to charge its 24 kWh battery, whereas a 2019 Tesla Model 3 will draw 8-12 kW to charge its 75 kWh battery. The combination of these large draws, and the rapid sales growth, significantly increase both the severity and likelihood of dangerous coincident peaks that utilities should be concerned with. During our EV load study, Charge the North, annual load curves were created for three groups of EVs that included a different mix of vehicles types based on battery capacities. On one of the days the long-range BEV group created a daily peak of over 72 kW, which could easily damage a residential transformer on its own.

With EVs tendency to cluster in specific neighbourhoods, more workplaces beginning to offer charging to employees, and public charging stations becoming more common in places like retail outlets, universities or hospitals, it would not be uncommon that you could have 5 vehicles charging on the same transformer. As with the SMUD case study, this could potentially be only the tip of the iceberg as the Model 3 was not a part of this program either.

Changes in charging behaviour

Most EV charging occurs at home with the old adage that household charging accounts for 90% of EV load. This figure needs to be changed as during Charge the North it was found that the percentage had decreased from 90% to 72%. A large portion of this drop can be attributed to an increase in the availability of workplace charging. More companies are offering workplace charging and during the study it was discovered that 80% of all workplace charging was free to the driver. If more companies adopt this practice workplace will surely continue to grow as not only is free for the EV owner but it provides access to people who may not have it otherwise, such as people in condos or apartment buildings. The US Department of Energy announced that as of May 2019 there are more than 68,800 public Level 2 and DC fast charging units throughout the United States. This infrastructure will only continue to grow with initiatives to phase-out of fossil fuel vehicles, like the proposed legislation in California and Seattle, are launched. Another thing to consider is the evolution of battery technology and the increases in battery capacities. To compare, a 2014 Nissan Leaf had a range of ~80 miles, while a 2019 Tesla Model 3 has a range of ~300 miles. This means that the Tesla will have to be charged less frequently, but when it does charge it will consume much more energy. This trend will continue to grow as battery capacity is a key sales feature for electric vehicles. For example, Rivian claims their upcoming R1T electric truck will have a range of over 400 miles and will have a 180 kWh battery. This combination of large energy draws and unpredictable charging habits has the potential to negatively impact the grid if utilities are not prepared. 

Other findings from Charge the North

Charge the North was a groundbreaking research project launched to address the impact of electric vehicles in Canada. It was developed with support from Natural Resources Canada’s Energy Innovation Program and set out to better understand how electric vehicles are being charged and driven, as well as the related effects on the existing electrical infrastructure. It was the world’s largest EV charging study and answered a number of questions such as the impact of time-of-use (TOU) rates on peak load, and the effects of seasonal climate, geography and commute distance on charging behaviour.

One key learning of this study was that vehicle-side data is critical for infrastructure readiness as seemingly simple questions like “Where are vehicles charging?” can only be accurately answered when all charging events are captured regardless of location, charging level and if the infrastructure is networked or not. Other more in depth questions, such as “How does charging behaviour differ between vehicle-type and between rural/urban owners?” and “What are the seasonal impacts on charging?” can only be answered with vehicle-side data as EV charging infrastructure does not gather any information related to vehicle utilization or efficiency.

A summary report of Charge the North can be downloaded here.

New data is better but Utilities need profile their own territory

Reviewing data from a new report is a lot like buying the newest cell phone. It’s groundbreaking when it’s released, and soon it will be outdated. Obviously utilities need to review case studies, like Charge the North, and the newer the information the better. However, the EV landscape is changing so rapidly that what is true today may not be the case tomorrow. That is not to say that older reports are obsolete as analyzing trends in the industry is the only way to predict what is on the horizon. What utilities should be aware of is the limitations of this generalized analysis. Every service territory is going to be unique and warrants its own profiling study. Commuting patterns, climate and model-specific market share all play a significant role in when creating load profiles.

The best solution for utilities to understand how EVs are driving and charging in their territory is to incorporate an ongoing profiling program into their load management strategy. SmartCharge Profile is a scalable solution that ensures utilities have all the data required to make accurate planning decisions. It is the first step toward managing electric vehicle charging load and can grow as the number of EVs in the territory increases. 

Click here to learn more about SmartCharge Profile and how to start profiling your service territory.