CNG Hybrid Power System for Mobile Vehicles

This project developed a high efficiency, compressed natural gas-hybrid electric power system for mobile off-road agricultural equipment

Mike Terzo, CEO of Terzo Power Systems, posing with lithium-ion battery packs in front of a prototype CNG hybrid-electric nut harvester

Terzo Power Systems, LLC.


El Dorado Hills, CA

Recipient Location


Senate District


Assembly District



Amount Spent



Project Status

Project Result

The researchers finalized the design of the prototype CNG hybrid-electric harvester and plan to commercialize the hybrid subsystems (e.g., high voltage safety hub, electrified HVAC cab comfort system, and electrohydraulic system) to support a variety of off-road mobile equipment. Supplier delays, equipment failures, and COVID-19 prevented the researchers from completing the real world in-use demonstration. Instead, the team conducted the demonstration in a simulated orchard environment and compared the data with documented diesel emission factors. The CNG hybrid-electric power system enabled a 27 percent reduction in CO2 emissions and 43 percent reduction in fuel costs. The final report was submitted in March 2021 and is in the publications process.

The Issue

The agricultural sector is responsible for a significant portion of pollutant emissions in the San Joaquin Valley Air Basin. Cleaner alternatives to conventional diesel powered off-road agricultural vehicles will be necessary to reduce criteria pollutant and greenhouse gas emissions. Powering off-road vehicles with a non-diesel engine presents unique challenges due to torque requirements, vehicle control constraints, highly varied application-specific work functions, and hydraulic power integration. No cost-effective diesel alternatives currently exist for powering these high-torque off-road vehicles in the agricultural sector.

Project Innovation

This project developed an easy-to-integrate, cost-effective, natural gas hybrid-electric power system that can replace diesel power systems on mobile agricultural equipment. The hybrid power system uses an integrated battery system that allows the engine to be decoupled from the electrified propulsion and hydraulic systems. The hybrid power system improves system efficiency, reduces emissions, creates healthier working environments, and provides a transitional platform to zero emission vehicles in the future. The researchers aimed to integrate the system on an almond harvester and demonstrate it in real world operation at an orchard.

Project Benefits

This project is developing a natural gas, hybrid-electric power system that can achieve the same performance as diesel engines while reducing emissions and improving efficiency when integrated with heavy-duty off-road vehicles. The system is designed to be modular and adaptable to a wide variety of off-road applications. The system can also serve as a transitional platform for zero emission off-road vehicles that will become more feasible as infrastructure availability and battery technology improves.

Environmental & Public Health

Environmental Sustainability

The project achieved a 27 percent reduction in CO2 emissions by decoupling the propulsion and hydraulics using hybridization. NOx and PM emission reductions were achieved by switching from diesel engine to a downsized CNG engine.

Key Project Members

Project Member

Michael Terzo



Western Integrated Technologies, Inc.


A-1 Alternative Fuel Systems


H.G. Makelim Company


Contact the Team