Hybrid Diesel-Electric Forestry Harvesting Trucks

Lead Proponent

FPInnovations

Project Objectives

FPInnovations is collaborating with the federal and provincial governments as well as with the transportation industry to design, develop and test an ‘’upfit kit’’ that will render a standard forestry semi-trailer truck into a parallel hybrid tractor-trailer. The combination of high energy demands and challenging terrain favor a hybrid configuration where an electric motor is integrated onto the trailer. The assistance of the electric motor will reduce fuel consumption while also increasing traction on steep grades and challenging road surfaces. In addition, the hybrid tractor-trailer configuration will result in reduced greenhouse gas emissions, reduced cost (downtime) of haul assists while also improving braking capacity via regenerative braking.

The scope of the project is to design, develop and test two prototypes. The application and service environment of each tractor-trailer configuration is different. The first prototype will use a logging trailer and will be designed for Quebec’s forestry environment, whereas the second prototype will be based on a biomass trailer and will be destined for British Columbia’s forestry sector. Testing will be conducted in both a controlled setting as well as in real operation.

Although the scope is currently limited to developing, testing and evaluating the performance of the prototypes, efforts are being made to commercialize the system. Some of the challenges being tackled include maximising energy capture and efficiency while minimizing the added weight and cost of the system.

Expected Results

The electric propulsion system can increase the fuel efficiency of Class 8 trucks by up to 15%, depending on the application and drive cycle. Although average values of fuel savings will be less than 15%, the improvement in efficiency will translate into significant cost savings for the operator as well as reduced exposure to volatility in fuel prices. As a direct result of the fuel savings, the hybrid configuration can result in significant greenhouse gas reductions reaching 40 tonnes per truck per year, depending on its utilization rate.

Adding an electrically driven axle to the trailer can increase a truck's traction by almost 50% on slippery surfaces and off-road conditions, therefore delivering a mobility advantage. In addition, the system provides additional power for going up steep hills. This means more reliable access to fibre and less downtime due to stuck trucks, both of which mean more cost savings and, thus, more income for the operator.

The electric motor can provide up to 250 kW (335 hp) of regenerative braking power which will recharge the batteries as well as reduce the use of service brakes on sustained descents. Not only does this increase the margin of safety in mountainous terrain, but it also increases brake life and reduces maintenance cost.

In addition to the safety benefits stemming from added braking capacity, the electric powertrain will reduce fuel costs, brake maintenance costs and lost opportunity costs due to downtime. The savings from reduced fuel consumption alone can be significant but will depend on the application, drive cycle and the system’s utilization rate. The added traction and lesser dependency on heavy machinery for haul assists can also amount to significant savings, while also providing new opportunities.