SUBCTECH
POWERING UP SUBSEA OPERATIONS Powered by Inside Marine
Platinum supporters
insidemarine.com
SUBCTECH
I PROFILE
In the ever-evolving realm of underwater technology, German firm SubCtech stands out with its innovative approach to ocean monitoring and subsea power solutions. Guided by the expertise of founder and CEO Stefan Marx, and COO Sören Johannsen, the company has carved a significant niche in this highly specialised industry. Richard Hagan sat down with both leaders to delve into SubCtech’s pioneering products, the challenges of subsea engineering and the sustainability of modern subsea energy storage.
140 Inside marine
B
ased in Kiel, Germany,
three sectors: offshore energy, under-
SubCtech has two
water vehicles and standard subsea
primary business
power products.
units – Ocean Monitoring and Ocean
According to founder and CEO Stefan
Power. The company began by manu-
Marx, SubCtech’s Ocean Power unit
facturing products to monitor seawater
offers both standard batteries and
quality, and over time, its focus evolved
bespoke solutions: “We are able to offer
to meet the increasing demand for
solutions that fit into the customer’s
battery power underwater.
available space and within its weight
From its relatively small beginnings
limitations - that’s where our roots lie and
crafting small underwater batteries,
that’s the service that has delivered our
the firm now boasts a staggering 1 MWh
growth thus far.”
battery storage system set to ship later this year. SubCtech’s Ocean Power unit
Record-breaking storage The company’s engineering prowess
manufactures subsea batteries that can
was on full display in late 2023 with
be deployed aboard underwater vehicles
SubCtech’s unveiling of the latest,
- particularly unmanned vehicles - or as
greatest and biggest battery that it has
backups for oil and gas industry applica-
ever produced: a jaw-dropping 1 MWh
tions offshore. To ensure its customers
battery storage system.
are comprehensively serviced, the
The battery, which was produced to
Ocean Power unit is subdivided into
order for a client, is the first MHw battery
Inside marine 141
SUBCTECH
I PROFILE
in the world. But it is also only one
in order to accommodate growing
amongst many other batteries sold by
demand for the company’s products.
SubCtech each year. The company’s
Following several relocations around Kiel
off-the-shelf battery solutions that
to accommodate its growing workforce
it calls ‘Big Jim’ and ‘Long John’, are
and workload, SubCtech has put down
perennial best-sellers. Both battery
roots via the construction of its own
units have standard physical dimensions
production space. Its large new facility
and similar weights, but the innards can
includes 1,300sqm of covered space
be customised according to the cus-
and 1,500sqm of outdoor/storage areas.
tomer’s specific requirements, including
A move to a 4,000 sqm building is planned.
both the capacity and voltage – both
SubCtech’s products are qualified
within set limitations. For vehicle-based solutions, SubCtech
according to military standards, and all are certified by Det Norske Veritas (DNV),
offers three different standard battery
an internationally accredited registrar
housing diameters, namely 260mm,
and classification society headquartered
310mm and 416mm internal diameter sizes,
in Norway. This DNV certification, which
but bespoke sizes, energy, power and
seeks to guarantee the safeguarding
voltage ranges are available on request.
of life, property and the environment, ensures not only total peace of mind for
Quality German engineering
the company’s products but crucially, it
SubCtech was founded in 2010 by current
is also a legal qualification for any equip-
CEO Stefan Marx, who boasts over 30
ment fitted to the deck of a vessel.
years’ experience working in ocean-related industries in various scientific and business
The importance of materials
roles. The company was originally head-
SubCtech sources the highest-quality
quartered in a small town near Kiel, but
raw materials from around the world
soon moved into Kiel proper, where its staff
for the construction of its products. COO
count has gradually risen from 20 to 76,
Sören Johannsen highlighted the reason
144 Inside marine
SUBCTECH
I PROFILE
that’s so important:
products, so many components that our
“The steps from prototyping
products need for deep-sea operations
to operational use for any
simply aren’t available on the market,
material and any product is a long
and so we have to make them ourselves.”
process involving testing and certifica-
The same applies to the company’s
tions. There’s a big difference with the
production machinery and even its
quality of materials used underwater and
testbed equipment, almost all of which
our task is to sell a fully qualified, 100 per
had to be developed and built in-house
cent secure product.”
since it simply didn’t exist to buy.
One of these materials is titanium,
Perhaps mercifully, then, one of the
which is used for every battery’s pressure
most important components - the lithium
hull. The pressure hull and most of the
battery cells themselves - are sourced
battery’s internal components are
from well-known producers with whom
manufactured at SubCtech.
SubCtech has supply contracts.
“We build most of the components in-house, including the pressure vessel,”
Sustainable electric power
Mr Marx said: “we also develop and pro-
While rechargeable lithium-ion batteries
duce the battery management systems,
have become commonplace in the daily
hardware, software, testing, control
lives of most consumers, it’s a relatively
systems and all battery components
new technology where subsea operations
in-house. While we’d prefer to use existing
are concerned. “It’s a big step forward for
146 Inside marine
the subsea industry and it’s an important topic for us,” Mr Marx confirmed. “particularly in terms of the way in which it improves the sustainability of the industry. “Firstly, because we’re replacing primary batteries with rechargeable batteries, and secondly because hydraulic systems are being replaced by battery-electric sys-
The recycling process must follow
tems which have a design life of 25 years;
strict legal guidelines to ensure full
so it’s very robust and that makes it very
transparency, as Mr Johannsen pointed
sustainable because clients don’t have to
out: “The recycling is strictly regulated
replace it frequently. Lowering CAPEX and
by German law, requiring that every
OPEX costs is important - it’s beneficial to
item we recycle be documented so
us, our customers and our partners and
that the flow back to raw material is
ultimately it will lower energy prices.”
also documented.”
At the end of one of SubCtech’s battery
Concluding, Mr Marx highlighted how
lives, all of the components can be recycled.
the company’s best assets are driving it
Customers can simply return the batteries
forward: “We’ve learned over the years
to SubCtech, which then forwards them to
that even as a medium-sized company,
specialist partners for recycling. Although
we’re able to move the world a little bit.
they’re also fully recyclable, the titanium
Today, we have the best products with
pressure hulls housing SubCtech’s bat-
a great reputation and a high-quality
teries have an endless design life and
team. In my 30 years in the industry,
are simply reused by the customer.
that’s the recipe for success.”
n
Inside marine 147