CTEP/NTEP

What are NTEP and CTEP for EV Charging?

The National Type Evaluation Program (NTEP) and California Type Evaluation Program (CTEP) are both metering certification programs with goals to ensure chargers meet recognized standards for accuracy, and transparency for charging transactions that are based on the amount of electricity delivered.

NTEP

NTEP is based on specifications in the National Institute of Standards and Technology (NIST) Handbook 44 (HB 44) and was adopted by most U.S. states on January 1, 2025 (some states are still in the process of adoption). Since then, compliance with HB 44 has been a regulation in these states, and NTEP is the program that administers the certification process.

Certification is only required for chargers that apply billing tariffs based on the amount of electricity in kilowatt-hours (kWh) delivered to ensure that customers only pay for what they use. For example, a charger provided by a company at a workplace that offers free charging for its employees does not require NTEP certification.

CTEP

The California Type Evaluation Program (CTEP) is a certification program run by the California Department of Food and Agriculture’s Division of Measurements and Standards (DMS) to ensure commercial measuring devices comply with a variety of California-specific regulations. In the context of EV charging, its purpose is to ensure chargers comply with standards for accuracy, transparency, and reliability.

The requirement for CTEP certification has been in effect in California since January 1, 2021, for new AC level 2 chargers, and since January 1, 2023, for new DC fast chargers.

What are the requirements for certification?

The requirements for NTEP certification are detailed in NIST HB 44, while requirements for CTEP certification are specified in the California Code of Regulations (CCR). The regulations in the CCR are based on NIST HB 44 but include stricter environmental and operational standards imposed by the state of California.

Without going into too many technical details, these certifications are designed to ensure the following:

• Accuracy: EV chargers must accurately measure the amount of electricity in kWh delivered to a vehicle and display the measurement on a screen that customers can easily read.
• Transparency: EV chargers must clearly display the total energy delivered, (kWh), the unit cost of energy (e.g., $ per kWh), and the total cost of the session. For chargers in California, CTEP also requires that they provide either a printed or digital receipt that shows the date and time of the charging session, a detailed breakdown of the energy cost per kWh, and total energy delivered.
• Reliability: Both the software and hardware in EV chargers must be tamper-proof to prevent intrusions that could cause inaccurate measurements.
• Durability: EV chargers must remain accurate even under extreme weather conditions (such as heat, cold, or humidity).
• Identifiability: Chargers must be clearly labeled with information about the manufacturer, model, and serial number so they can easily be identified and tracked.

How are NTEP and CTEP different?

While both certifications aim to achieve similar goals, there are five fundamental differences between them that a network operator must consider.

1. Scope: NTEP is applicable nationally and certification is required in most U.S. states. CTEP is only mandatory for public chargers in California. To operate in California, a network operator is likely to need both certifications. Conversely, operators receiving CTEP certification are also likely to meet all the standards required for NTEP certification, enabling them to operate in other U.S. states.
2. Standards: Both NTEP and CTEP are based on NIST HB 44, but CTEP also adds requirements from the California CCR.
3. Receipts: Receipts are mandatory for CTEP certification, but not necessarily for NTEP certification.
4. Durability: While NTEP requires durability under general environmental conditions, CTEP applies stricter testing for more extreme conditions.
5. Reliability: While both certifications require EVSEs to be tamper-proof, CTEP requires enhanced sealing specific to California.

Why are NTEP and CTEP certifications important

While EV adoption is growing rapidly, the industry is still in its early stages. To sustain the same level of growth, people must be confident that EV charging is safe, fair, and reliable. These certifications foster consumer confidence by ensuring customers only pay for the electricity they consume and have complete transparency over the price they are paying. The certifications also ensure that network operators maintain a high level of service by requiring reliable and accurate equipment.

Driivz enables network operators to achieve NTEP/CTEP certification

The Driivz EV charging and energy management platform provides network operators with the capabilities they need to achieve NTEP/CTEP certification. Driivz supports its customers by registering periodic meter values and cross-referencing them with the billing tariff set for the charger. If the unit energy cost changes during a charging session, Driivz will break down the session and calculate the cost per time interval. All the data is available through the Driivz operator portal or via API and can be used to generate an NTEP/CTEP-compliant receipt that can then be printed by the charger or made digitally available to the customer.