No. 94 · APRIL 2022

SUMITOMO ELECTRIC TECHNICAL REVIEWPREFATORY NOTE

Featured Topic: C ontributing to a Zero-Carbon Society
through Technology Development

Masaki SHIRAYAMAManaging Director
General Manager, Electric Wire & Cable, Energy Business Unit

1. Decarbonization over the Power Cable
MarketEfforts toward a Zero-Carbon society to curb global
warming have become a major trend worldwide. Back inOctober 2020, the Japanese government proclaimed the targetof achieving Carbon-Neutral by 2050, referred in “GreenGrowth Strategy,” with a policy to make concerted efforts onthe development of renewables and hydrogen energy sources,
namely “carbon neutral innovation,” with aims to strengthen
the competitiveness of Japanese industry. In addition, a “GreenInnovation Funding” was founded to promote it.
The Public-Private council set a high expectation on theoffshore wind industry with a vision to achieve an ambitious
target capacity of 30-45 GW by 2040. Meanwhile, these initiatives are facing challenges such as the disperse renewableenergy resources and the impact of typhoons and other severe
weather conditions on the offshore wind power facilities.
Europe, the preceding region to adopt renewable energy,
has been engaged in identifying potential areas for harvesting
renewable resources. The energy is then transmitted withdirect current (DC) cables utilizing cross-border interconnectors to meet the demand for electricity over a large area. The
transition and adoption of such energy schemes are rapidly
underway worldwide, including India, United States, andChina. In Japan, a master plan involving the construction of alarge-scale and ultra-long-distance submarine cable system of
4-8 GW from Hokkaido (the northernmost island of Japan) tothe Tokyo metropolitan area is under consideration.
Furthermore, as the interest in floating wind turbines is likely
to increase in the near future, the development of dynamic
cables for such applications is needed.

2. Societal Contribution through TechnologicalDevelopment
Sumitomo Copper Rolling Works was founded in 1897
for the manufacturing and sales of copper plates, rods, andwires with raw copper mined from Mt. Besshi, which underpins the wire and cable business of Sumitomo ElectricIndustries, Ltd. In 1911, the 11 kV high-voltage undergroundpower transmission cable manufactured by Sumitomo Electric
was put to practical use for the first time in Japan. Since then,the Company has been developing high-voltage and high-capacity cables by fully utilizing its innovative technology ininsulating materials and manufacturing technologies. Withcross-linked polyethylene (XLPE) insulated cables, which are
the mainstream at present, we have successfully put in practice the world’s highest voltage of 500kV (AC) and 400kV(DC), contributing to technological innovation in energy infrastructure. In other respects, the Company has been contributing to the stable power supply with the development ofpreventive technology to detect “partial discharge,” which
eventually leads to breakdown, especially when power supply
is interrupted by natural disasters or accidents, and byimproving the accuracy of technologies to pinpoint the fault
location along with short responsive time for cable repair
along with strengthened service capacity to facilitate the maintenance works of aging circuitries.
In recent years, Sumitomo Electric Group companies
have focused their R&D efforts on technologies such as power
reservation batteries, IoT, and AI-based smart power management to resolve the instability of renewable energy.
Moreover, these companies are coping with the transition to circular economy internationally by developing newmaterials to increase the recyclability of decommissioned
cables and reducing CO2 emissions in manufacturing to minimize the environmental burden.

3. Development in DC Cable Technology
In 1954, the world’s first DC submarine cable made ofinsulation paper impregnated with high-viscosity oil was usedfor DC power transmission between mainland Sweden andGotland islands. Similarly, a DC 250 kV oil-filled (OF) cable
was installed between Honshu (the main island of Japan) andHokkaido, and since then, OF cables have been used globally.
Contrarily, XLPE cables, which have been studied sincethe 1970s, had the advantage of not leaking in the event of amarine accident. However, the problem of the deteriorating
DC insulation performance due to the accumulations of spacecharge in the XLPE insulation remained to be solved.
Through years of research and development, including
the introduction of inorganic additives to the insulating material with high space charge resistance, a 250 kV DC submarine
XLPE cable was installed in 2012 linking Hokkaido andHonshu, which still holds the world’s highest voltage record.
Following the milestone above, Sumitomo Electric wasawarded for the construction of a 140 km DC 400 kV interconnector, namely NEMO Link between the United Kingdomand Belgium. This was the world’s first DC interconnector
Prefatory Note1（1）SUMITOMO ELECTRIC TECHNICAL REVIEW

project that adopted an XLPE cable operating at 400 kV. TheNEMO Link has been transmitting power without fault since
its completion in January 2019, contributing to the stableenergy supply between the countries.

No. 94 · APRIL 2022

SPSS, s EMSA contributes to stable and economical energy
management (Fig. 1). Proposals to solve the issues of energy
security at regional industrial parks, residential areas, remoteislands, etc. with the use of distributed photovoltaic systems in
combination with energy management technologies, theCompany will provide solutions to achieve energy saving,
reduction in cost and CO2 emissions.

DeploymenttoVPPs

Contribution to increased incorporation of renewableenergy and grid stabilization

Virtual power plant (VPP)
A virtual power plant controls
small-scale renewableenergy sources, storagebatteries, and other energy
resources in an integrated
manner to have them
function as a single power
station. Its advantages
include eﬀectiveness incontinuous and increasing
incorporation of renewableenergy sources and power
grid stabilization.

Photo 1. Submarine cable installation (NEMO project)

ThermalPV

StoragebatterysystemPV:Photo Voltaic
EV:Electric Vehicles

PV

StoragebatteryPowergenerator

Factory energy management system

Sumitomo Electric strives in building a sustainable
society with a focus on three mottos of “Minimize
Environmental Burden,” “Improve Energy Quality,” and“Ensure Energy Security” in a drastically changing powersystems today.
The utilization of renewable energies contributes tominimizing environmental burden, but at the same time, it iscontradictory in that large-scale development of renewablesources to improve power quality brings environmental
impact. Thus, it is equally important to use technologies likebattery storage and smart power control in conjunction withthe development of renewable energy. Technologies like redox
flow battery storage systems for industrial or grids application,
Power Depo III energy storage for households; taking advantage of IoT and AI in Energy Management Systems (EMS) –Wind

power generation

Aggregator

Factory︓FEMS

4. Development in Smart Energy SystemTechnologyPV

power generation

Power transmission anddistribution network

power generation

Substationequipment

Recognition of the successful operation and achievements stated above led to the award of another contract fromthe German Transmission System Operator (GTSO) Amprion
for a 525 kV DC XLPE cable system with a route length of
320 km. This system will transmit offshore wind energy
generated in the North Sea to southern Germany, where electricity demand and consumption are high. Sumitomo Electricis the only Asian corporation qualified for thePre-Qualification (PQ) process of the project, along with fourothers appointed by the Employer. Sumitomo Electric passed
the stringent PQ test that continued for nearly two years.
Construction is planned to begin circa 2024.
A collaboration with Siemens Energy in the sector ofhigh-voltage DC power transmission started in 2017, and in
the same year, a consortium between the two companies wonan order for a 320 kV DC transmission project in southernIndia. In 2021, the consortium was awarded the 320 kV DC
Greenlink project connecting Ireland and Great Britain with atarget completion in 2024.
As the market and projected demand for cross-borderinterconnectors and large-scale offshore wind platforms that
require export cables for transmitting electricity back toonshore power stations are expected to grow rapidly not onlyin Europe but also in Asia, where utilization of DC-XLPE
cables is highly anticipated. Sumitomo Electric is confident
with its technology to meet the market needs.

Hydropower
generation

Nuclearpower generation

PVsystemOﬃce︓BEMS

Building energy management system

Distributed energy resources sources including
photovoltaic power generation, generators, andstorage batteries

EVsystem
Powergenerator

Storagebattery

Home︓HEMS

Home energy management system

OpenADR, ECHONET Lite, and Wi-SUN

Total coordination

Development ofnetworked systems

s EMSA in conjunction with SPSS provides various solutions
in response to demand for decarbonization solutions.

Fig. 1. Smart energy system

5. Conclusion
In Japan, the energy sector accounts for 40% of CO2
emissions in total, as Sumitomo Electric is demonstrating its
efforts and contribution toward a zero-carbon society; decarbonization of other sectors like transportation and heavyindustries (petro-chemical, steel mill, etc.) is equallyimportant. Furthermore, as the transportation sector is facing amajor transition towards electrically driven vehicles, thischange will have a significant impact on the energy sector.
The impact will not merely be an increase in demand for electricity, but also a reduction in environmental burden throughthe use of storage batteries in these vehicles, the maintenanceand improvement of power quality, and assurance of energy
security. Sumitomo Electric is confident with the combinationof its core technologies in the areas of mobility, energy, andcommunications to create new values.
Additionally, it is important to improve and refine theelectricity storage technology for achieving a higher utility inrenewable energy. In the near future, the development of
low-cost, high-capacity storage batteries, hydrogen production
using renewable energy, and the deployment of mobilehydrogen storage will be realized. For data centers, energy
conservation is anticipated to be industrialized at the device
level, which may initiate a new technological innovation.
Realizing a zero-carbon society by 2050 is a common
challenge for humanity. Sumitomo Electric is committed tobuilding a sustainable society with its core technologies
focused on energy, while collaborating with stakeholders toprovide new products and services.
• ‌SPSS is a trademark or registered trademark of Nissin Electric Co., Ltd.
• ‌Power Depo and s EMSA are trademarks or registered trademarks of
Sumitomo Electric Industries, Ltd.

Featured Topic: Contributing to a Zero-Carbon Society through Technology Development

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