Overview

CE-CERT has studied port emissions since 2003, beginning with locomotives and later expanding to drayage vehicles and equipment. More recently, the Center has analyzed emissions from harbor craft, ferries, and ocean-going vessels. Massive port facilities use diesel engines to load, unload, and transport cargo in and out of terminals. The Ports of Los Angeles and Long Beach are major sources of air pollution in the South Coast Basin. The Emissions and Fuels Research Group at CE-CERT developed some of the earliest emissions profiles for different ocean-going vessel engines and fuels. The Center also partnered with the U.S. EPA and the Mexican Federal Government on the first study of low-sulfur marine fuels in the Gulf of Mexico. Additional studies have evaluated hybrid technologies for drayage vehicles and harbor craft.

Research Projects

• Medium and Heavy-Duty EV Deployment - Data Collection

  Plug-in and electric vehicle options in the medium-duty (MD) and heavy-duty (HD) categories have grown rapidly in recent years. Fleet interest in electric vehicles is increasing. This includes transit buses, school buses, trucks, and off-road equipment. With this rapid growth, reliable data on MD and HD electric vehicle performance is needed. These data provide insights into vehicle use and support future deployment strategies.

  This project collects data from MD and HD electric vehicles. A smaller group of light-duty (LD) electric vehicles is also included. The project builds on deployments underway across several regions, including:

  • Electric transit buses (NY, IL, UT, CA)

  • Electric school buses (NY and CA)

  • Electric trucks (fleets and freight operations in CA)

  • Electric off-road equipment (ports and goods movement in CA)

  • EVs used for clean mobility or workplace transportation

  Data is collected using onboard data loggers and standardized protocols. The team draws on its extensive experience in vehicle data collection. Logger types may include CALSTART and CE-CERT-owned units, OEM-installed systems, or third-party telematics. OEM participation will help ensure reliable vehicle-level data access.

  Data will include:

  1. Vehicle performance

  2. Charging data from off-board chargers

  3. Electricity consumption

  4. Facility operation data

  5. Climate data

  6. Vehicle descriptors (make, model, year, battery capacity)

  Data is collected for at least 12 months and stored on secure servers managed by CALSTART and/or CE-CERT. It is verified, cleaned, anonymized, and analyzed using standardized workflows. CE-CERT will collaborate with NREL to define parameters and ensure compatibility with DOE national lab databases. Summarized results will include charts, tables, and visualizations. All data will be made available through secure FTP access to approved users.

  Lead Researcher: Dr. Kent Johnson
  Co-researchers: Dr. Kanok Booriboonsomsin, Dr. Thomas Durbin

• Optimized Hybrid Ultra-Low NOx Class 8 Heavy Duty Natural Gas Truck

  GTI, UCR, FEV North America, US Hybrid, and Cummins Westport are partnering on a hybrid natural gas Class 8 truck. The goal is to develop and demonstrate a fully optimized plug-in configuration. The truck uses a 40 kWh lithium-ion battery, a 236 hp electric motor, and a CWI L9N engine certified below 0.02 g/bhp-hr NOx. A parallel hybrid configuration allows the engine to power the vehicle during cruising. The electric motor supports acceleration and energy recovery during braking.

  In hybrid mode, the truck produces over 500 hp. This exceeds the performance of typical 12-liter engines while reducing emissions and improving fuel economy. The truck will support EV-only mode for zero-emission driving. It includes plug-in charging and engine start-stop to reduce idling. Controllers and components will be optimized for drayage operations based on early simulation results.

  The project builds on earlier programs (ARV-11-029 and PIR-13-014). It begins with a functioning hybrid vehicle and near-zero NOx engine. This allows the team to focus on whole-system control optimization. The demonstration will occur on a chassis dynamometer at UCR. This will compare performance with diesel and baseline natural gas trucks using multiple standardized duty cycles. These include the LA and Long Beach drayage cycle, ARB 4-mode cycle, and UDDS.

  The project aims to develop an efficient energy management system. This system will coordinate hybrid and engine power based on driver demand and battery status. A dSPACE prototype controller will replace the stock ECU to enhance hybrid integration. Torque and power split control is a key development focus.

  Drayage trucks were selected due to their emissions impact, high usage, and operation in sensitive regions. The project also supports tools for integrating NG engines with electric motors and different drivetrains. Outcomes include better drivability, improved fuel economy, and reduced GHG and criteria pollutants.

  Lead Researcher: Dr. Kent Johnson
  Co-researcher: Dr. Thomas Durbin

• OSAR: Phase 1 Sensor Evaluation on Heavy Duty Trucks

  Heavy-duty vehicles are a major source of NOx and PM emissions. Emissions standards now require advanced controls like DPFs and SCR systems. These systems perform well in certification tests but may not meet targets during real-world use. This is a concern in the South Coast AQMD, where stricter ozone limits apply.

  SCR-equipped diesel engines can reduce NOx by 90% in lab tests. Under low-load conditions, in-use NOx emissions may reach ten times the certified value (Dixit et al., 2017; Misra et al., 2013). Ultra-low NOx natural gas engines show much better results—even 100 times below the standard (Johnson et al., 2017; 2018).

  Zero-emission and hybrid trucks can eliminate tailpipe emissions. However, widespread adoption is limited. Urban-focused policies such as ultra-low NOx zones may help accelerate deployment. CARB has proposed a 0.02 g/bhp-hr NOx standard, a low-load test cycle, and changes to Not-To-Exceed protocols.

  A different solution involves continuous onboard measurement. The proposed OSAR system uses vehicle control sensors to monitor emissions in real time. These sensors are accurate, durable, and repeatable. Tan et al. (2018) found high NOx levels from 72 trucks during low-temperature use due to poor SCR efficiency. Montes (2018) found OBD sensors were typically within 15% of lab values. However, individual readings varied.

  One limitation is that OBD NOx sensors disable below 250°C to avoid humidity damage. NGK developed prototypes that work in colder conditions. These are important because SCR-equipped engines emit the most NOx under cold starts. Yang et al. (2018) found the prototypes matched PEMS readings within ±10% across real-world cycles.

  This project will guide development of onboard reporting systems. These systems can help reduce emissions by validating compliance under actual operating conditions. Funding from AQMD will be matched by industry partners. Results may lead to instrumentation of new trucks and retrofits for legacy fleets.

  Lead Researcher: Dr. Kent Johnson
  Co-researcher: Dr. Thomas Durbin

• Advanced Off-Road NG Vehicle Demonstration and Evaluation

  This project responds to the California Energy Commission’s call for transportation technologies that reduce emissions and improve efficiency. UCR is partnering with Gradstein and Associates to evaluate natural gas (NG) technologies in off-road applications. The project will test NG and RNG-fueled yard hostlers, alongside electric and Tier 4 diesel models.

  Hostlers will use 9-liter NZ engines and 6.7-liter 0.1 g NOx engines. Fuels will include fossil natural gas and blends of RNG, delivered in LNG and CNG forms. CNG-compatible fuel systems will be installed on select vehicles. A fuel gas sensor will be integrated into one engine to monitor fuel quality and adjust controls.

  The project includes a well-to-wheel analysis of each fuel pathway. Funding for 20 LNG yard hostlers enables extensive testing without major hardware costs. This effort will generate operational and emissions data for multiple fuel and engine combinations.

  Lead Researcher: Dr. Kent Johnson
  Co-researcher: Dr. Chan Seung Park

• Off-road Equipment data monitoring

  UC Riverside is supporting the Port of Long Beach’s (POLB) contract with CARB by collecting data on advanced off-road equipment. UCR will provide data logging and possibly PEMS testing for battery-electric and fuel-cell vehicles. These include:

  • 2 battery-electric top handlers (Taylor/BYD) at SSA terminal

  • 1 battery-electric top handler, 1 yard hostler (Kalmar/TransPower), and 1 fuel-cell yard hostler (CNHTC/LOOP Energy) at LBCT terminal

  Diesel counterparts at both terminals will also be monitored for comparison.

  Lead Researcher: Dr. Kent Johnson
  Co-researchers: Dr. Kanok Booriboonsomsin, Dr. Thomas Durbin

• Technologies to reduce emissions associated with freight movement

  This project tests emissions from technologies that reduce pollution related to freight movement. It measures criteria pollutants (CO, NOx, PM2.5, THC), climate pollutants (CO2, black carbon, methane), and air toxics. Sources include scrubbers, LNG vessels, non-distillate fuels on ocean-going vessels (OGVs), and engines from cargo-handling and harbor craft.

  Technologies already help reduce PM, SOx, and NOx. However, additional reductions are needed to meet California’s public health, air quality, and climate targets. This includes further efforts to reduce GHG and short-lived climate pollutants (SLCPs) from freight systems.

  Lead Researcher: Dr. Kent Johnson
  Co-researcher: Dr. Wayne Miller

• 200 Vehicle Study

  UC Riverside is a leader in real-world emissions testing. In the past five years, UCR has supported EPA’s in-use testing program. It led validation of portable emissions measurement systems (PEMS) using its Mobile Emissions Laboratory (MEL). MEL is a 53-foot trailer with a full dilution tunnel and 1065-compliant system. It has been cross-validated with Southwest Research Institute.

  The study evaluated in-use PEMS performance across multiple platforms. These included light- and heavy-duty vehicles, construction equipment, ships, port vehicles, trains, and aircraft. The team developed specialized tools. These include a microsoot sensor-based PEMS and a PG350 gas analyzer for ISO 8178 testing.

  These systems have been used in CARB and Caltrans projects. UCR also created protocols for verifying emissions control technologies on generators, marine vessels, and rubber-tired gantry cranes.

  Lead Researcher: Dr. Thomas Durbin

• SOA Forming Potential from HD Diesel Vehicles and HD Natural Gas Vehicles

  This project evaluates secondary emissions from two NG trucks and two diesel trucks under real-world driving. It complements SCAQMD’s 200-vehicle program. Primary emissions are measured using CE-CERT’s chassis dynamometer and Mobile Emissions Lab. Tests will include PM mass, particle number, black carbon, carbonyls, and regulated pollutants.

  Each vehicle’s exhaust will be collected and aged in CE-CERT’s mobile chamber. Secondary organic aerosol (SOA) formation will be analyzed. The chamber uses real-time instruments to characterize POA and SOA. The study includes:

  1. SOA from current-generation HD vehicles

  2. SOA from NG trucks, which is underrepresented in the literature

  This will be the first study to assess SOA formation from NG HDVs. These vehicles emit VOCs, NOx, and PM—key precursors to SOA and ozone. SOA affects visibility, climate, and health. Prior studies (e.g., Bahreini et al., 2012) showed diesel vehicles contribute little to SOA, while gasoline vehicles are the primary sources. There is limited data on SOA from natural gas trucks.

  Lead Researcher: Dr. Georgios Karavalakis
  Co-researcher: Dr. David Cocker

• Pollutant Emission Rates from Maritime Sources

  This project quantifies emissions from commercial harbor craft (CHC) in California. Real-world emissions may exceed certification values, even after accounting for expected deterioration. UCR will use a Portable Emissions Measurement System (PEMS) to test three CHC vessels over two weeks.

  CARB will select vessels based on remote sensing data. UCR will analyze the data and report results to ARB and project partners. This effort is part of a multi-institutional contract led by UC Berkeley, with USC and UCR as subcontractors.

  Lead Researcher: Dr. Heejung Jung