Efficiency: Are Ultra-Fast EV Chargers Worth the Investment?

Each Charge Point Operator (CPO) claims their utilization is between 10% -15%. But does this metric really tell the whole story?

For instance, 90% of Allego's charger network consists of AC chargers, while Fastned's network is exclusively Fast DC chargers, yet both claim to have a utilization around 12% to 15%.

Despite these figures and both companies reporting positive operational EBITDA, their bottom lines remain in the red.

Whether it's a network with numerous AC chargers or exclusively DC fast chargers, using only the time-based utilization metric seems insufficient. Utilization is key to profitability, and a more comprehensive measure is needed to truly understand and improve financial performance.

Time-Based vs. Power-Based Utilization

Time-based utilization considers only the available time and time used for charging sessions, but power utilization paints a more accurate picture. By comparing the max available power to the delivered power, we see a drastically different result. A CPO can be very proud to reach over 5% power utilization, considering the increasing costs of high-output chargers, which do not rise linearly with output.

Electrify America (EA): A Treasure Trove of Data

I've always sought reliable data, scrutinizing Fastned and Allego annual reports, and analyzing the sparse data from Hungarian authorities. Now, I’ve found a treasure: Electrify America ’s detailed station-level data covering:

• 1.000+ locations
• 4600 chargers
• 11 million sessions
• 5.7 million hours of charging
• almost 400 GWh of energy delivered

This extensive dataset provides a statistically significant foundation to draw robust and reliable conclusions about EV charger utilization and performance on the US DC charging market.

Crunching the Numbers

1. Time-based Utilization: EA at about 14%, similar to Fastned's 13% in NL and higher than DE and other countries at below 10%.
2. Power-based Utilization: EA achieves about 5%, while Fastned in NL is at 3% and other countries below 2%.

Charging Speeds and Session Insights

EA averages 200 KW per charger, with sessions typically lasting around 30 minutes and delivering about 32.5 kWh. In contrast, Fastned’s network averages over 300 KW per charger, yet sessions deliver just over 30 kWh in a similar timeframe.

This discrepancy highlights the limitation of current car batteries and charging behaviors, raising the question: Is it worth investing in ultra-fast chargers? While high-speed chargers are a great marketing tool, their practical value is limited given current battery technology and usage patterns.

Several factors contribute to the gap between average charging speeds and the charger’s maximum capacity:

• Vehicle Limitations: Many EVs can’t sustain maximum charging rates throughout the session. Older models and those with smaller batteries often can’t utilize the highest speeds.
• Session Characteristics: Partial charging sessions and topping up from higher states of charge result in lower average speeds as the charging rate drops when the battery nears full capacity.
• Environmental Factors: Extreme temperatures and inadequate cooling systems can reduce charging efficiency and speed.
• Charger Utilization and Downtime: Maintenance, low demand periods, and load balancing across multiple vehicles can lower average charging speeds and utilization rates.
• Data Reporting Issues: Inaccuracies in session recording and setup times during initial connections and payments can skew average speed calculations.
• Micro Sessions: Representing about 30% of total initiated sessions, micro sessions—those shorter than a minute and less than 0.5 kWh—only account for 0.3% of the delivered energy. Despite their low energy contribution, they add complexity to utilization metrics.

These factors suggest that while ultra-fast chargers are impressive on paper, their real-world benefits are constrained by current technology and user behavior, necessitating a more balanced and strategic approach to charging infrastructure investment.

Annual kWh Delivered per Charger

Electrify America (EA) averages about 81,000 kWh per charger per year, a significantly higher figure compared to other operators.

For instance, Fastned averages around 69,000 kWh per charger per year in the Netherlands, 51,000 kWh in Germany, and below 40,000 kWh in other countries.

Meanwhile, Hungary is nearing 15,000 kWh per charger per year.

These numbers highlight how EA's network is achieving higher utilization rates, possibly due to better infrastructure, higher demand, or more strategic locations. The disparity in these figures underscores the importance of network efficiency and strategic deployment in maximizing charger utilization.

Regional Charging Behaviors

• Charging Time: Americans are the most patient, averaging over 30 minutes per session, followed by Germans at over 30 minutes, and the Dutch at around 23 minutes.
• Charging Amount: Americans charge about 35 kWh per session, Fastned users in NL charge below 25 kWh, and in Hungary, it's about 20 kWh.

Our statistical analysis revealed some key insights:

1. Max Charge Speed (KW) vs. 2023 Minute per Session: As the maximum charge speed increases, the average minutes per session tend to decrease. This suggests that higher-speed chargers reduce the time vehicles spend charging per session. The trend line in the graph reinforces this negative relationship.
2. Max Charge Speed (KW) vs. kWh per Session: Higher maximum charge speeds are associated with higher kWh delivered per session. This indicates that faster chargers can deliver more energy in each session, as shown by the positive trend line in the graph.
3. Max Charge Speed (KW) vs. kWh-based Utilization Rate: The relationship between maximum charge speed and kWh-based utilization rate is weak, suggesting that increased charge speed does not directly translate to proportional increases in kWh utilization rates. The trend line in the graph is relatively flat, indicating this weak relationship.
4. Correlation Matrix of Key Variables: The matrix shows a moderate negative correlation between max charge speed and minutes per session, and a moderate positive correlation between max charge speed and kWh per session. However, the correlations with utilization rates are weak, indicating that other factors, such as session duration, play a more significant role.

Cost vs. Benefit Analysis

To justify the investment in a 350 kW charger over a 50 kW charger, with a 7% discount rate over an assumed 10-year lifetime, a price difference of approximately $0.30 per kWh is needed to achieve a positive NPV.

Given that the typical market prices for fast charging in the US range between $0.30 and $0.60 per kWh, achieving such a markup is challenging.

This raises the question: Is it realistic to expect a $0.30 per kWh price difference in this competitive and volatile market? The analysis suggests that further optimization, additional revenue streams, or cost reductions would be necessary to make this investment financially viable.

To Conclude:

The data from Electrify America and Fastned provides valuable insights into the utilization and efficiency of EV chargers. While Electrify America shows higher utilization rates both in time-based and power-based metrics, the analysis reveals significant challenges in justifying the investment in ultra-fast chargers given current market conditions and technological limitations.

Obviously, it is not a straightforward comparison between the USA and, in this case, mostly the Netherlands, but it is interesting to see that the Netherlands has already achieved a higher BEV penetration compared to the US, yet performance metrics seem to favor the US. It can be the higher Tesla penetration or different user attitudes. We would need more detailed data from Europe to further investigate these differences.

Key Takeaways (for me):

• Utilization Metrics: Time-based utilization alone is insufficient. Power-based utilization offers a more comprehensive understanding of charger efficiency and profitability.
• Charging Speeds: Higher charging speeds reduce session times and increase kWh delivered per session, but the relationship with overall utilization rates is weak.
• Regional Behaviors: Different regions exhibit varying charging behaviors, impacting utilization rates and energy delivery per session.
• Cost vs. Benefit: Achieving a $0.30 per kWh price difference to justify ultra-fast chargers is challenging. Optimization, additional revenue streams, and cost reductions are essential for financial viability.

In conclusion, while faster and more chargers can improve utilization, strategic deployment, and operational efficiency are crucial to maximizing returns and ensuring the sustainability of charging networks. The insights from EA's data highlight the need for a balanced approach that considers both the technological capabilities of vehicles and the economic realities of the market.