Is battery technology – and its perceived high costs – slowing the widespread adoption of next-generation hybrid electric propulsion in
the marine world?
“Today, the price of batteries is not the show-stopper it used to be.
The question is whether a battery solution fits the operational profile or not.
“If you have a small ferry on a limited, predictable route where it’s possible to recharge or switch over batteries, then there are big savings. Either way, if you can link up for an onshore charge, then the difference in costs between shore electricity and electricity on board means the additional cost of the batteries is paid off fairly quickly – it could be inside a couple of years.
But the expectation is that the price of batteries will drop even further.
“We are just moving from the visionary stage and into real applications. New design is containers that you can load and unload and leave ashore to charge and pick up later.
It’s achievable with today’s technology.
“So, the question no longer centers around price and capability, but more
length of voyage and the size of the batteries you need.
Right now, certain vessels are more suited than others, and some will not reap the benefits as the pack becomes so big you are just paying to transport batteries.
So despite the advances, they’re still heavy and take up a lot of volume.”
In addition, the size of the battery bank depends on how the differences
between the maximum and minimum energy outputs are passed across the bank:
“It’s linked not to overall power so much as the shape of the power variation curve, that is, to how much you draw out and how much you
put in. So, while one battery bank might be sized to deal with a 1MW peak-shaving application, given different demands you might need four times that for only half the engine power.”