I don’t think there is going to be much of a sales increase up to about 2020 or so. JD Power had 7.7% in 2018, I’m actually below that in 2018. The reason is it’s going to take time to bring out the new technology. It will take more time to build up sales so that you can actually design the vehicles around the hybrid system and that’s where you get a lot of cost reduction.

In the 2020 timeframe, I think you’ll see this all come together. [Hybrids] will go mainstream. By 2030, I’m saying 70% of the market. This is why I’m bullish about conventional hybrids; its not so much what’s happening now. Costs are too high, but they are going to come down.

—John German

German based his analysis on ICCT-sponsored updates of two studies, one by FEV on hybrid system manufacturing costs, and one by Ricardo on efficiency modeling. He focused on developments in the so-called P2 system—generally a single motor with two clutches integrated between the engine and the transmissions. Examples of this system are recent introductions by Nissan, VW, Hyundai, BMW and Mercedes, he noted.

FEV system boundaries for cost evaluation: powersplit (left) and P2 (right). Click to enlarge. Source: John German, ICCT

Referencing earlier work by the National Academy and MIT, German said that the P2 system can deliver 90% of the benefit at 1/3 of the cost of an input powersplit system using planetary gearing, as exemplified by the Toyota and Ford hybrid systems.

Input powersplit systems rely on two large motors (generator and traction) and offer tremendous flexibility in operation, German said. One major benefit is the optimization of city cycle efficiency. However, while one can run the motors at any load point required or desired, the Achilles’s heel is the fixed torque split between engine and generator he said.

If you’re just cruising down the road, you have power going to the generator recovered by the motor back into propulsion—those are both losses. Your motor now has to be sized to handle the combined output of the generator and battery pack. The generator has to handle regenerative braking plus the power from the engine. This results in two very large motors.

—John German

The P2 system, by contrast, relies simply on a clutch between the engine and the transmission. With the clutch, you can run on the electric motor alone, and increase the amount of regen. The Achilles’ heel for this system, German said, is starting the engine when running down the road in electric mode. Different manufacturers are exploring different approaches: Hyundai with a separate belt-alternator-starter system, Nissan with a second clutch, VW by retaining a conventional torque converter, he said.

ICCT contracted with FEV to update that company’s earlier study on costs. In that update, FEV tore down 5 different European vehicles to determine hybrid costs. Among the high level results German presented at the SAE symposium was the finding that net incremental direct manufacturing costs for both the powersplit and the P2 systems are essentially the same, with the exception of the transmission and motor system. This element is substantially less expensive in the P2 system (€703 vs €875).

Ricardo’s updated study on efficiencies—with an eye to the 2020 timeframe—using a variety of models found that the P2 system offers 102% of the benefit of a powersplit system at 8% lower cost. Furthermore, German suggested, the P2 system has future opportunity for cost reduction, including:

• High‐powerLi‐ion batteries—i.e., smaller, lighter, lower-cost;
• Vehicle load reduction
• Integrating the motor into transmission and system into vehicle;
• Experience; and
• Additional synergies and features

The P2 applications have been low-volume applications. If it’s a low-volume application, the motors and clutches have been hung on to the existing architecture. This is not what you want to do for high volume. There is a lot more potential for P2.

—John German