Diesel Hydraulic Hybrids

Most of us are familiar by now with the concept of hybrid cars. Hybrids usually have two power sources and one power sink. The popular Prius, for instance, has a small efficient gasoline engine which is one source of power, and an electric motor which stores power into a battery (an energy sink) and then generates energy from the battery (an energy source). The power sink acts like a flywheel, conserving energy until it's needed.

One problem with gas-electric hybrids: what to do with the batteries? Presumably we'll figure that problem out later.

Another problem: why aren't we using diesel-hydraulic hybrids? Diesel-hydraulics have two three key advantages over gas-electrics.

• Better efficiency. Diesel-hydraulics approach the efficiency of fuel cells, but they can be manufactured today.


• Better performance. Hydraulics can provide much faster acceleration than electric motors.


• No batteries to dispose of. Just some accumulators that can be melted down.

We may never achieve high volume diesel-hydraulic hybrid cars because gas-electric hybrids got to market earlier and because consumers perceive anything with electric power as "cleaner" than anything with diesel power.

Perhaps this is an example of the inefficiency of efficient markets.