(John Kemp is a Reuters market analyst. The views expressed are
By John Kemp
LONDON, June 19 China's power engineers have
become world leaders in ultra-high-voltage transmission systems
connecting far-off power sources with cities hungry for
China already has seven ultra-high-voltage (UHV) lines in
operation, more than any other country, carrying power over
thousands of kilometres at around 800,000 or even 1 million
In April, the government gave the go-ahead to build another
line operating at 1 million volts between rural Anhui province
and the cities of Nanjing and Shanghai.
The National Energy Administration, which is part of the
powerful National Development and Reform Commission, the
country's top economic regulator, has ambitious plans for as
many as 12 inter-regional ultra-high-voltage transmission
corridors spanning the country.
Most of the existing and planned transmission lines run
broadly west to east and are intended to take power from western
and central regions, where there are abundant hydro, coal, gas,
solar and wind resources, to major industrial cities near the
With so many projects planned, State Grid Corp of China
(SGCC) is looking forward to a "golden era" of UHV development
at home and likens its UHV experience to a "golden business
card" to help it win business overseas, according to a company
release ("China enters a golden era of UHV development", May
State Grid says UHV will give China a unified national
electricity market for the first time as well as helping to meet
booming electricity demand and cut pollution.
UHV is intended to link the country's existing regional
grids in a national network. But it is also meant to herald much
bigger changes in the way China uses energy.
SGCC wants the coal- and oil-fired boilers used in
factories, offices and district heating systems across northern
China to be replaced by electric heating to cut the air
pollution that kills millions of people every year.
Much of the electricity for the grid would still be
generated from coal, a source of greenhouse emissions as well as
But large central power stations are likely to be more
efficient than the small and old boilers used in many northern
areas to provide winter heating, and it would be easier to fit
them with scrubbers and other technology to cut pollution.
Shifting from coal to electric heating would also enable
China to integrate more clean sources of power such as wind and
solar into the energy mix.
State Grid calls it the "coal-to-electricity" programme and
says it would help meet many of the government's plans for
increasing energy efficiency, cutting pollution, and reducing
dependence on imported oil.
Coal-to-electricity aims to replace coal-burning stoves for
industrial and residential purposes with electric ones to curb
air pollution, SGCC Executive Vice-President Yang Qing told a
conference on green electricity in November 2013.
Oil-to-electricity could help develop the market for
electric vehicles and electric irrigation in rural areas, to cut
reliance on gasoline and diesel, Yang explained ("SGCC proposes
coal-to-electricity to control smog", Xinhua, Nov. 8, 2013).
Under a programme launched last year, SGCC intends to
replace many district heating boilers with large-scale heat
pumps, according to Xinhua.
SGCC's strategy for cleaning up China's pollution problem
and cutting greenhouse emissions is essentially similar to the
climate plans being pursued by governments in Europe and North
The strategy consists of two separate transitions:
electrification and decarbonisation. It would shift more energy
consumption away from direct use of fossil fuels onto the
electricity grid, then cut emissions from power plants by
replacing fossil fuels with more renewables and nuclear power.
LOST IN TRANSMISSION
China's problem is that main sources of fossil fuels and
renewables for power generation are hundreds and even thousands
of kilometres from where the electricity is most needed.
All transmission systems lose energy between generation and
the end consumer as the electricity encounters resistance in the
wires along the way and some energy is lost as heat.
On average, about 6 percent of the electrical energy
transmitted and distributed in the United States was lost
between 1990 and 2012, according to the U.S. Energy Information
The further electricity is transmitted, the more is lost.
Economic considerations therefore tend to cap transmission
One reason why solar power stations in North Africa and the
Sahara cannot currently be used to supply electricity to
Northern Europe is that the transmission losses would be too
But it is possible to reduce the proportion of energy lost
by stepping up the voltage, which is why China and a number of
other countries have begun developing ultra-high-voltage systems
to carry power over much longer distances.
In the United States, most long-distance transmission lines
operate at 230kV, 345kV, 400kV or sometimes 500kV, where kV
stands for thousand volts. In Britain, most of the National Grid
operates at 275kV or 400kV.
But China's existing UHV systems mostly operate at 800kV,
nearly twice as high, or even 1,000 kV in some cases.
GOLDEN ERA OF UHV
Operating at extremely high voltages creates technical
challenges as transformers, towers, cables and relays must run
safely in a more demanding environment than normal.
Much of the early work on UHV systems was done by electrical
engineering companies such as Siemens and ABB
. However, SGCC has mastered the technology and says 90
percent of the engineering work has now been localised.
China's existing UHV lines have delivered more than 160
terrawatt-hours of electricity since they were commissioned,
about the same as the annual consumption of the state of Ohio or
half what Britain uses in a year.
The company says its UHV lines have successfully withstood
extreme weather, including heat, cold and storms.
Now China wants to export that expertise to other developing
and developed countries looking to build long-distance
transmission lines or super-grids.
In February, a consortium led by SGCC won a 30-year
concession to build and operate a 2,000-km (1,240-mile), 800kV
UHV line in Brazil. The transmission system will carry power
from the Belo Monte dam in northern Brazil to the major
consumption centres in the southeast.
"The successful bid fully reflects the company's advantages
in this area and will promote China's technology, equipment and
experience on UHV transmission into Brazilian and other overseas
markets," SGCC trumpeted in a statement ("SGCC won the bid of
Brazil's Belo Monte Hydropower UHV Transmission Project", Feb.
In the past, some policymakers have expressed concerns about
linking up China's entire electricity network in one giant
super-grid, fearing more interconnectedness would also increase
the risk of nationwide power blackouts.
But according to SGCC, top officials, including Chinese
Premier Li Keqiang, endorsed the UHV super-grid strategy at a
meeting in April.
"The Premier's stance ended the argument of whether to
construct UHV. The answer is YES and MORE. This year will be a
golden era of approving and constructing lots of UHV projects."
In practice, not all these projects are likely to be
approved. SGCC has had its plans scaled back before. But enough
will go into construction in the next few years to transform
China's electricity industry radically.
(Editing by Dale Hudson)