The document proposes a concept called Jidai for offshore production of renewable hydrogen in Japan. Jidai would involve installing a semi-submersible platform offshore that uses wind energy to power electrolysis of seawater to produce hydrogen. The hydrogen would be compressed and stored on the platform before being offloaded via shuttle tankers. Jidai aims to help Japan transition to renewable energy and hydrogen fuel while freeing up land space and reducing emissions. It could also be applied in other coastal regions to facilitate clean energy production and distribution.

1. SAFER, SMARTER, GREENER
WHAT IS THE NEXT STEP?
DNV GL SUMMER PROJECT 2015
Offshore production of renewable hydrogen.

2. 02 DNV GL SUMMER PROJECT 2015 Offshore production of renewable hydrogen
Energy enables human development and has helped
lifting millions of people into a global middle class.
However, the energy mix today is dominated by fossil
fuels, and this strains the earth’s climate and limited
resources.
Continued growth and development requires cleaner
alternatives. Recent technological advances and cost
reductions are making renewable energy sources
more accessible, but the pace at which we are moving
is not fast enough.
Being young today, we have benefited from the
developments driven by our parents’ generation. Now,
it is our turn to take responsibility for the next era.
By building on existing knowledge from the oil & gas,
maritime, and energy sectors, we are exploring new
ways of incorporating renewable energy sources into
the global energy system.
Shipping
800 GWh/day
Heavy transportation
4,700 GWh/day
The internet
5,000 GWh/day
Energy consumption
The next step

3. Offshore production of renewable hydrogen DNV GL SUMMER PROJECT 2015 03
04 Hydrogen
06 Japan
08 Jidai
10 Process
12 Platform
14 Figures
15 Benefits
16 New Era
Cars
11,000 GWh/day
Industry
25,000 GWh/day
Residential
18,000 GWh/day
Content

4. 04 DNV GL SUMMER PROJECT 2015 Offshore production of renewable hydrogen
*Based on the fuel consumption of Toyota Mirai
10L
130 km*Hydrogen gasSeawater
1.1 kg
Travel 130 km on a
bucket of water!

5. Offshore production of renewable hydrogen DNV GL SUMMER PROJECT 2015 05
Using hydrogen as a fuel was imagined by the visionary
French writer, Jules Verne, who also described subma-
rines and space travel almost 150 years ago. Hydrogen
is an excellent energy carrier with a high energy density,
and now it is finally ready to unleash its full potential.
Developments in fuel cell technology, led by the auto-
motive industry, have made hydrogen an attractive fuel
for transportation as well as for residential use. Further,
the energy needed for production of hydrogen can be
supplied by renewable sources, which are becoming
increasingly cost-efficient.
Offshore wind energy is developing rapidly and global
installed capacity has doubled from 2011 to 2014. The
emergence of floating wind technology provides even
more opportunities. Still, only 2.4% of the world’s wind
power production is done offshore.
The energy contained in the powerful ocean winds is
almost unlimited. Hydrogen enables us to take the energy
from remote locations and integrate it with society.
I believe that water will one day be
employed as fuel, that hydrogen and
oxygen, which constitute it, will furnish an
inexhaustible source of heat and light. […]
Water will be the coal of the future.
– Jules Verne, 1874
“

6. 06 DNV GL SUMMER PROJECT 2015 Offshore production of renewable hydrogen
Combining natural resources, technological expertise,
and a strong drive for new energy solutions, Japan is
set to become the world’s first hydrogen society.
Politics
Today, Japan’s energy supply is dominated by
expensive import of fossil fuels, contributing
to high CO2 emissions and low energy
self-sufficiency. Moving into the future,
the Japanese government is dedicated to
increase the share of renewable energy.
Offshore
The exclusive economic sea zone of Japan
is the world’s 6th
largest, a big contrast to
the limited space and densely populated
areas on land. The large ocean areas have
provided Japan with extensive experience
and expertise in the maritime sector.
– Shinzō Abe, Prime Minister of Japan
Japan is back

7. Offshore production of renewable hydrogen DNV GL SUMMER PROJECT 2015 07
Hydrogen
Japan has a vision of becoming a carbon-
neutral hydrogen society by 2040. Fuel cell
vehicles have already made a successful
entry into the Japanese market, and within
15 years, hydrogen is foreseen to be an
integrated part of the Japanese society.
Technology
Japan is the world’s third largest economy,
and has for many years been a main
driver in technological development.
Combining innovation with experience in
manufacturing and industry, Japan has all
the prerequisites needed to develop new
and clean energy technology.
Wind
Strong and stable winds offshore provide
Japan with an abundant source of
renewable energy. Because of this, Japan
is investing heavily in the development of
floating wind turbine technology, which will
enable better utilization of the vast offshore
wind resources.
Adding one idea …

8. 08 DNV GL SUMMER PROJECT 2015 Offshore production of renewable hydrogen

9. Offshore production of renewable hydrogen DNV GL SUMMER PROJECT 2015 09
JIDAI
The concept name Jidai is Japanese, meaning “New Era”.

10. 10 DNV GL SUMMER PROJECT 2015 Offshore production of renewable hydrogen
500
MW
Offshore, seawater is abundant. However,
the process needs water with very high
purity, and seawater is therefore desali-
nated in three energy-efficient steps. First,
the water is passed through a sand filter,
before it undergoes a double-pass reverse
osmosis. Finally, electrodeionization is used
to remove remaining salts. The ultra-pure
water is then fed to the electrolysers.
Producing hydrogen
1. Water purification 2. Electrolysis 3. Compression
Multiple stacks of polymer exchange
membrane (PEM) electrolysers produce
high-purity hydrogen and oxygen gas from
water, and gives the plant enough capacity
to match the maximal power output of
the wind farm. The PEM electrolysers are
compact and flexible, responding to the
intermittent power supply on a second to
second basis.
Produced hydrogen gas is compressed to
700 bar in an ionic compressor to reduce
storage volume. The pressure of the gas
is gradually increased in five steps, keep-
ing the energy loss close to zero. With
minimal maintenance requirements, the
compressors are well suited for offshore
operation.
Water purification CompressionElectrolysis

11. Offshore production of renewable hydrogen DNV GL SUMMER PROJECT 2015 11
Handling
intermittency
4. Storage
Where does the energy go?
Hydrogen
Electrolysis losses
Compression
Offloading
Platform operation
Water purification
Pumps, cooling systems
High-pressure hydrogen gas is stored
in a module-based tank system, waiting
to be offloaded. By using lightweight
composite tanks, both weight and cost
are reduced. The storage capacity is 400
tonnes of hydrogen at 700 bar, equivalent
to three days of average production.
All system components have been specifically chosen to with-
stand the intermittent power supply from the wind turbines as
well as frequent start-stop cycles without undue delay or wear.
In addition, a combined battery and fuel cell backup system
provides the necessary power for keeping critical equipment
in operation when wind power is unavailable. This evens out
power fluctuations during production cut-in and cut-out. The
backup system also supplies enough energy to restart and
de‑ice the wind turbines after production shutdowns.
Storage

12. 12 DNV GL SUMMER PROJECT 2015 Offshore production of renewable hydrogen
Designing the layout of the platform with easy access for
humans and machines, the maintenance and surveillance
can be automated when the technology for smarter
autonomous systems matures.
In case of failure or shutdown of the
windfarm, internal power production
using stored hydrogen and fuel cells
keeps the integrity of the platform.
Storing purified water in the pontoons
works as an integral part of the ballast
water system, and frees space on the
upper decks for production and storage.
A semi-submersible platform combines a small waterline
area and deep draft with a high moment of inertia, giving it
both stability and small responses to waves. This ensures a
safe operation even in harsh weather conditions.
Platform layout

13. Offshore production of renewable hydrogen DNV GL SUMMER PROJECT 2015 13
Overpressurization in the production and
storage areas is relieved by cold vents.
The liquid displacement shuttle system
secures a steady and efficient offloading of
the compressed hydrogen.
The transfer of hydrogen
to the shuttle tanker is
made via a buoy, allowing
safe offloading and a high
operational window.
The storage area is filled with inert gas,
preventing ignition in case of hydrogen
leakage, creating a safer system.
The production system consists of
several modules that can be changed
or repaired individually, adding
flexibility to the overall system.

14. 14 DNV GL SUMMER PROJECT 2015 Offshore production of renewable hydrogen
Key figures
€/kg
0
5
10
15
20
JidaiSolar
PV
Onshore
wind
Grid
electricity
H2 break-even price in Japan €/kg
Cost breakdown
42,000 tonnes/year
Production Commuters Petrol equivalent
400,000, 30 km/day 1.17 €/l *
EUR/year
Hydrogen produced from renewable sources will play a vital role in
the future energy market, ensuring self-sufficiency and lowering CO2
emissions. Jidai offers a cost-competitive solution and reduces the
need for electrical infrastructure. Challenges with limited space on
land, a restricted grid capacity and seismic activities make Jidai an
attractive solution for Japan.
0 20 40 60 80 100
OffloadingSupporting systems
Wind park
TransportPlatform
Compression and storageElectrolysis
*Delivered to port

15. Offshore production of renewable hydrogen DNV GL SUMMER PROJECT 2015 15
Provides work
opportunities
Estimated creation of
40,000 work years
Reduces
CO2 emissions
300,000 tonnes CO2
avoided each year
Frees land
space
To produce the same amount
of hydrogen would require
a land area of 20 km2
with
solar energy (PV)
Secures
energy supply
Reduces dependency
on imported fossil fuels
Maintains
safety
Less exposed to
earthquakes and tsunamis
Improves
air quality
The only emission from
fuel cell vehicles is water
Social benefits

16. 16 DNV GL SUMMER PROJECT 2015 Offshore production of renewable hydrogen
Japan has made a brave commitment to become a
renewable hydrogen society by 2040, and they have the
need, will, and competence to do it. We believe that Jidai
has the potential to play a vital role in Japan’s hydrogen
vision. The technology is available today, and by 2030 we
believe it will be cost-efficient.
Although designed for Japan, Jidai is not limited by
­geography or market. As a standardized system, the con-
cept can easily be installed in other areas and adapted to
specific local conditions. The modular process is scala-
ble, the floating structure simple, and the offloading and
transportation system flexible. It is a particularly attractive
solution in coastal regions where electric power is expen-
sive, or where land resources are scarce.
Jidai offers a smart way of harvesting the abundant off-
shore resources and facilitates a complete value chain of
clean energy. Produced from wind power, hydrogen be-
comes a zero-emission fuel from creation to consumption.
We believe renewable hydrogen is the next step.
Jidai is how we propose to take it.
The New Era

17. Offshore production of renewable hydrogen DNV GL SUMMER PROJECT 2015 17
Industry
Shipping
Cars
The internet
Heavy
transportation
Residential
JIDAI

18. 18 DNV GL SUMMER PROJECT 2015 Offshore production of renewable hydrogen
From left, back row: Are Kaspersen (project manager DNV GL), Daniel Jakobsen, Adrian Mekki, Eirin Fjellanger, Morten Aslesen,
Lars-Henrik Nysteen, Kristoffer Bjerkelund, Christian Carstensen, Egil Gustafsson. Front row: Katrine Storaker, Tadashi Uchihira,
Karin Cederberg, Zhenying Wu, Elsa Härdelin, Kristina Dahlberg (DNV GL).
Thank you, DNV GL
The DNV GL Summer Project 2015 involves thirteen
Master’s students, from eight universities and of five
nationalities. The outcome of our project is developed
by challenging each other’s ideas and building on each
other’s competences. Seven amazing weeks have come
to an end, and we would like to thank DNV GL for the
opportunity given to us and for an unforgettable time. We
are grateful towards all DNV GL colleagues and external
experts who have helped and enabled us to realize this
project. Your availability, positivity and support have been
highly appreciated.

19. Offshore production of renewable hydrogen DNV GL SUMMER PROJECT 2015 19
Sources: Barath Raghavan, The energy and emergy of internet, ICSI and US Berkeley. EIA, Annual Energy outlook 2015 with projections to 2040,
April 2015. METI, Strategic Energy Plan 2014, The Japanese Ministry of Economy, Technology and Industry, April 2014. Ministry of Economy,
Technology and Industry, FY2013 Annual Report on Energy, METI, 2014. Mizuho Information & Research Institute, Study on current situation and
future forecast of hydrogen demand and supply, New Energy and Industrial Technology Deveopment Organization, 2013. NEDO, Hydrogen
White paper, NEDO, 2014. Siemens AG, What is the real cost of offshore wind?, Siemens AG, 2014. Y. Nagayama, T. Ohya & H. Ota, M. Sakai, K.
Watanabe, Y. Kobayashi ,”Japan’s Largest Photovoltaic Power Plant —Turnkey Construction Contract and Commissioning of Oita Solar Power—,” in
Hitachi Review, vol. 63, pp. 398–402, July 2014.
A rapid transition to a low carbon future
requires new ideas. We need an inspiring
vision of the future in order to create the
new technologies and solutions needed.
The green future represents plenty of
opportunities for innovation.
– Bjørn K. Haugland, Chief Sustainability Officer, DNV GL
“

20. SAFER, SMARTER, GREENER
DNV GL AS
NO-1322 Høvik, Norway
Tel: +47 67 57 99 00
www.dnvgl.com
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