Boat International - June 2018

MORE BANG

FORYOURBUCK

Insearchofalowercostforstoragebatteries

SUPERYACHTS HAVE BEENquietly
getting greener for some time.
Regulations limiting emissions from
ships, known as IMO Tier I, came into
force in 2005 and since then there have
been two more tiers – each cutting the
amount of harmful sulphur (SOx), nitric
oxide (NOx) and particulate matter that
yachts can emit into the atmosphere.
Manufacturers have come up with various
clever ways to meet these increasingly
strict standards – catalytic reducers,
exhaust scrubbers and by simply making
the combustion process more eicient.
But as the industry faces a future of even
tighter regulation, and in an era of volatile
diesel prices, it has become necessary –
and expedient – to ask the simple
question: what comes next?

NEW FUTURE FUELS

EMERGE

T

he obvious choice in the hunt
for cleaner alternatives is to
look at biofuel, hydrogen gas,
hydrogen fuel cells and liquefied natural
gas (LNG). According to classification
society DNV GL Maritime, LNG is the
only price-competitive fuel that can meet
existing and phasing-in regulations to
limit SOx, NOx, particulates and CO2
emissions without additional process
technology such as scrubbers, filters and
catalytic converters.
It’s an idea that’s gaining traction.
BMT Nigel Gee is building two 70 metre
LNG-powered ferries for service in the
Netherlands and, according toCruise
Industry News, 13 of the 73 (yes, 73) new
cruise ships on order are to be powered
by LNG. On 15 April, the International
Maritime Organisation reached an
agreement to cut CO2 emissions on ships
by 50 per cent by 2050. Much, but not
all, of those savings will be expected

to come from a switch to LNG in the

commercial sector.

But LNG has some disadvantages for

the leisure market, says James Roy from

BMT Nigel Gee. “It has an energy density

of between 50 and 60 per cent of diesel;

therefore the volume of fuel tanks for the

same range is higher for LNG.” LNG is

inherently more combustible and

requires more safety measures than

diesel, and it is much more complicated

to construct an LNG tank than a diesel

tank. “A shift to this fuel for yachts is

unlikely unless there is a seismic shift in

[LNG] access, acceptance of reduced

range by yacht owners and [increased]

regulation eliminating diesel exhaust

in ports, harbours and special

environmental areas,” says Roy.

Hans Konings, design manager for

Amels, sees the future being elsewhere.

“In 15 to 20 years, the only realistic

alternative to diesel will be hydrogen,

either gas or fuel cells, to charge batteries

that will power the propulsion and house

needs of yachts,” he says. “All industries

are looking for renewables because at

some time fossil fuel will be gone.

Bio-diesel will not be the ultimate

solution. Looking for clean energy, we

have wind, water, solar and hydrogen as

potential sources. This is not impossible.

We just have to look at ways of storing and

using it safely.”

The short-term solution is to use

diesel in more efficient ways. Hybrid

systems utilising power take-off (PTO)

and power take-in (PTI) configurations

will lower emissions and there are “all

kinds of smart power grids in

development to accommodate the needs

of various owners”, says Konings,

indicating various priorities such as

speed, silent running or range. “All the

yards are doing this with all sorts of

engine combinations to be more eicient.

The old-fashioned diesel connected

direct to a fixed prop operating at

a specific speed with no reduction gear is

theoretically the most efficient

propulsion, but yachts never sail at

nominal speed, so the PTO/PTI system is

best for our industry because it offers

options for various speeds,” he adds.

“Savannahis a perfect example of diesel,

electric and stored power. Even if

[Feadship is] a competitor, I am glad they

tried that.”

Batteries will play a part but there are

challenges in this direction too. It’s not

just the cost of batteries (100kWh storage

In 2012, the

production cost

of a lithium-ion

battery was about

£375 per kWh.

With research and

better production

methods, the

price has dropped

significantly to

about £125 to £140

per kWh. Tesla is

building an entirely

new lithium-metal

battery plant at

a cost of around

£4.2 billion that is

expected to lower

battery cost to

around£85to£90

perkWh.Atthat

level, the global

consultancy

McKinsey &

Company estimates

the market for

electric cars could

increase to £63

billion per year.

Lookingatitanother

way,theUSJoint

Centre for Energy

Storage Research

has set a goal to

develop batteries

that power a car for

the same distance

as a tank of fuel

(about 500 miles)

without significantly

increasing the

vehicle’s weight.

PHOTOGRAPHY: COPYRIGHT FEADSHIP; ICONS: FLATICON.COM