Introduction With the development of the Renewable Energy Sources worldwide, the concept of a global electricity network has been imagined in order to take advantage of the diversity from different time zones, seasons, load patterns and the intermittency of the generation, thus supporting a balanced coordination of power supply of all interconnected countries. In 2016, CIGRE decided to launch a feasibility study on this concept of global electricity network. In this respect, the WG C1.35 has been set up to provide a possible geographical and technical configuration and preconditions for its feasibility considering technology and economical aspects.

1. emissions on the climate, the energy awareness of the
population has changed.
In this respect the 2015 United Nations Climate
Change Conference, COP 21, agreed to a final global
pact to reduce their carbon output, and to do their best
to keep global warming below 2°C.
In the fight against climate changes, beside energy
efficiency, the development of renewable energies
is also an essential element. It requires the
implementation of ambitious co-development projects
to build wind and solar power plants in a large scale
and to be able to transmit the electricity over long
distance to consumptions areas.
The main driving force behind the Global Grid is
the harvesting of remote renewable sources, and
its key infrastructure element is the high capacity
long transmission lines. Wind farms and solar power
plants could supply load centers with green power
over long distances.
The resources were focused on the grid simulations
and analysis, using as most as possible data from past
and relevant international studies (e.g WEC).
Methodology
The study has limited the grid architecture to one
electrical node per region. This coarse granularity
is enough to provide a first quantitative assessment
of prospective interconnection capacities. Priority is
given to the identification of major electric transmission
corridors, meaning higher than 2 GW.
Although an interconnection between two regions •••
Introduction
With the development of the Renewable Energy
Sources worldwide, the concept of a global electricity
network has been imagined in order to take advantage
of the diversity from different time zones, seasons,
load patterns and the intermittency of the generation,
thus supporting a balanced coordination of power
supply of all interconnected countries.
In 2016, CIGRE decided to launch a feasibility study
on this concept of global electricity network. In this
respect, the WG C1.35 has been set up to provide a
possible geographical and technical configuration and
preconditions for its feasibility considering technology
and economical aspects.
The TB presents the results of this CIGRE concept
study. It addresses the challenges, benefits and
issues of uneven distribution of energy resources
across the world. The time horizon selected is 2050.
The study includes sensitivity analysis to different
factors: the capacity factors, the technology costs, and
the flexibility of the demand.
Background
The demand for electricity continues to grow as a
result of demographic changes, industrialization and
urbanization. The international energy references
like the International Energy Agency, and the World
Energy Council (WEC) still confirm the increase of
the electricity consumption, going from 22000 TWh in
2017 to 35000 TWh in 2040, and almost 40000 TWh
by 2050.
With the exhaustion of fossil resources, the increase
and volatility of prices, the effects of greenhouse gas
Members
J.YU, Convenor (CN), G.SANCHIS, Secretary (FR), K.BAKIC (SI),
N.CHAMOLLET (FR), A.KUMAR (SE), M.LE DU (FR), A.ILICETO (IT), Y .ZHANG (CN),
L.BELEKE TABU (RDC), S.CHATZIVASILEIADIS (DK), JL.RUAUD (RDC), D.RADU (BE),
J.FAN (CN), M.BERGER (BE), B.COVA (IT), M.STABILE (IT),
H.LI (CN), F.HEYMANN (PT), D.ERNST (BE), MA.DUPRE LA TOUR (FR), R.FONTENEAU (BE),
MM.DE VILLENA (BE), M.THEKU (ZA), M.RANJBAR (IR)
Global electricity network – Feasibility
study
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2. Results
For the reference case, meaning the isolated regions,
without any interconnection between regions, the
energy mix envisaged in 2050 by the WEC should lead
to an average cost of 54 €/MWh for generation. The
RES share (hydro, biomass, wind and solar) of this
production is 53%. The estimated CO2 emissions are
850 million tons per year (Mt/yr).
For the case with interconnections, the wind, solar, and
gas production technologies are optimized together
with the interconnections capacities. Nuclear, coal with
CCS, biomass and hydro production capacities are
imposed according to the isolated-regions case. •••
is represented by only one corridor, such a corridor
must be understood as several lines connecting
the two regions. Hence, the capacity of any single
corridor between two regions corresponds to the
sum of the capacities of all lines connecting these
two regions. The technologies considered in this
study include HVAC/HVDC overhead lines as well as
HVDC submarine cables. The figure 1 presents the 20
interconnections selected.
The scope of the feasibility is limited to one scenario.
However, the study performed different sensitivity
analyses in order to assess the impact of parameters.
The table 1 introduces the different case studies.
Figure 1 - The 20 interconnections selected for the Global Grid assessment
Table 1 - The different case studies for the sensitivity analysis
• Reference cases
– Isolated zones with no interconnections
– Reference case with interconnections
• Sensitivity studies
– Lower cost of interconnection between North-Africa and Europe
– Interconnection between Russia and North America made impossible
– Sensitivity to a higher costs of interconnections
– Modification of wind capacity factors in Central Asia and North East Asia
– Sensitivity to the losses in the interconnections
– Sensitivity to daily or seasonal storage possibilities
• More theoretical cases
– Only production allowed : solar photovoltaic and wind
– Only production allowed : solar photovoltaic
Imposed productions
• following WEC scenario:
Nuclear, coal with CCS,
biomass, hydro
• Wind and solar PV as in 2017
Optimized productions,
together with
interconnections
• Gas technologies (CCGT with
or without CCS, OCGT)
• New wind and solar PV
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3. there is an excess of production in North America,
the interconnection is used to export it to Asia and
Europe through Russia. On the opposite, when there
is a lack of production in North America (negative
residual production on the figure, mainly in summer
due to cooling) the interconnection is used from Russia
to North America, especially to get benefits of wind
productions in Central Asia (region 6).
The high level of interconnections in Asia allow for a
redistribution of production in the region. Much less
production for North-East Asia (region 4) and much
more production in Central Asia (zone 6, wind) and in
South-East and South Asia (regions 5 and 7, wind and
solar), getting the benefits of better capacity factors.
Finally, the use of interconnections selected according
to their profitability, leads to an average cost of 48€/
MWh for generation and interconnections. The RES
increases to 76%. The estimated CO2 emissions are
largely reduced to 343 Mt/yr.
Although this solution requires 2600 GW for the
cumulative capacity of the interconnections,
representing 17% of the installed generation capacities,
this solution is profitable.
The additional cost of the infrastructures (+100G€/
year) is largely compensated by the reduction of the
generation costs (-350G€/yr). The replacement of gas
production by wind and solar productions lowers the
global cost of the system.
The figure 3 shows the capacities and volume of
generation, for each technology, and for the case without
interconnections, and the case with interconnections. •••
The optimization procedure is seeking for a balance
between the costs of the interconnections depending
on their unit costs, and the benefits of mutualizing the
load curves of different zones and getting an access to
renewable productions with better capacity factors.
The figure 2 gives the optimized capacities (GW) either
for production and interconnection. The numbers in
bracket [ ] give the annual cost of interconnection in
billion euros.
Different noticeable results can be seen on this figure.
The most obvious one is the development of very
important capacity interconnection around Central Asia
(region 6):
- 409 GW to North-East Asia (region 4),
- 495 GW to South-East Asia (region 5),
- 240 GW to Russia (region 10).
This development is linked to huge capacities of wind
productions in Central Asia, explained by the very good
capacity factors. The 1426 GW installed capacity for
wind production is almost 10 times the total production
capacity installed in the reference case, with isolated
regions, far beyond the only needs of this zone. The
interconnections are used to provide renewable energy
in all surrounding zones.
The most expensive interconnection capacity is
developed between Russia and North America: 183
GW for 27 G€/yr. This interconnection is connecting
the Asian-European continent to the Americas and is
used in both directions. The main driver for the use
of this interconnection is the residual production in
North America (i.e. total production – total load): when
Figure 2 - The optimized capacities (GW) for generation and interconnections
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4. sources, instead of gas generation, reducing the total
cost for the worldwide community, and contributing to a
drastic reduction of CO2 emissions.
A follow-up WG C1.44 is starting with the objective to
challenge the present results with the implementation
of alternative solutions for flexibility as more storage,
and demand-side facilities within the region. 
The replacement of gas production by wind and solar
productions lowers the global cost of the system. The
total production costs are 330 G€/yr lower as illustrated
in the figure 4.
Conclusions
Obviously, the results of the feasibility study depend
on the assumptions selected, and on the different
parameters used for the simulations. Therefore, several
sensitivity analysis were performed in order to assess
the robustness of the results.
The sensitivity studies analyzed the sensitivity of the
results with the possibility: to impose some corridors,
to change the value of capacity factors, to take into
account the losses in interconnections, and to take into
account some storage facilities.
Finally, these sensitivity analysis show good resilience
of the results on the whole. Some light change occurs
on the total cost but without large impact, keeping
profitability for the interconnection solution.
Thus this CIGRE feasibility study shows, within the
limits and boundary conditions adopted, the added
value of interconnecting the continents in comparison
with keeping them separated.
The global electric network, compared to non-
interconnected grids, enables the use of wind and PV
Figure 3 - The share of each production technology, capacities and volumes – reference case with interconnections
Figure 4 - The repartition of the annual cost, reference case with
interconnections
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