is equal to about $100,000 to purchase),
but that batteries are heavy and even the
latest lithium-ion batteries are not
particularly energy dense. “Batteries
equal draught and draught does not equal
eiciency,” says Konings. “But batteries
are fabulous for harbour use because you
don’t have to start the stinking engines.
This technique, generating electricity to
be stored in a battery, will continue for
another 10 years, I think.”
HOPES FOR
HYDROGENT
he Netherlands, which has
committed to fossil-free ferries,
and Norway, an earlier adopter of
diesel-electric and electric-only ferries,
are both leaning towards hydrogen fuel
cell technology for marine application.
Hydrogen can be supplied as a pure gas
held in tanks or manufactured on site
through several processes, including solar
collectors, wind-powered electrolysis and
reforming, a process in which air, steam
and a fossil fuel such as diesel or LNG are
forced through a membrane to extract
hydrogen-rich gas and trap sulphur.
While reforming reduces the hydrogen
storage issue, the system is very
complicated and voluminous, according
to a spokesperson for BMT Nigel Gee.
But work persists on other hydrogen
methods. In the autumn of 2016,
PowerCell Sweden AB was contracted to
install a pair of prototype fuel cell S3
stacks on a Norwegian ship that will
create its own hydrogen from solar
electricity, thereby quadrupling its
autonomy. Much of the basis for
PowerCell’s development comes from
a research programme by Volvo, which
saw hydrogen as a suitable fuel for trucks,
buses and heavy equipment. A factor that
makes hydrogen interesting to the marine
industry is the efficiency of fuel cells
versus lithium-ion batteries. The
PowerCell products weigh 32.3kg per
100kW (135hp) of output and can be
stacked in series depending on the
required power.
Shipping is crucial for linking
locations along the Norwegian coast and
can cut travel times by half, according to
Andrea Boden, spokesman for PowerCell.
“At the same time, today’s motor vesselsAbove: the engine room
of the 83.5m Feadship
Savannah, housing
its innovative hybrid
power plant, which
Feadship estimates
has fuel savings of
30 per cent compared
to similar boats it has
launched. Savannah
is the first yacht to
operate with a single
Azipull running in the
slipstream of a variable
pitch propeller, righthttp://www.boatinternational.com | June 2018195