IEEE Power & Energy Magazine - November/December 2019 - 103

Key Measures and
Their Effectiveness
Retrofitting Coal-Fired
Generators in
Northeast China
In systems dominated by coal-fired
generators, increasing flexibility
is the primary technical measure
required to enhance the system's
capability to integrate VG. In 2016,
november/december 2019

200

169.9
5.76%

150

8
6

100

2015

2016

2017

2018

(%)

VG power plants have been equipped with high-voltage and the NEA issued a list of coal-fired generation retrofit pilot proj-
low-voltage ride-through capability, which improves their ects nationwide to enhance flexibility on the generation side.
ability to support power grids. The construction of interpro- Northeast China was the first region to implement the retro-
vincial and inter-regional transmission lines and generation fits, and most of the projects are located in this region. North-
dispatch over larger balancing areas has been completed to east China's power grid is single ac with a maximum load of
make use of diverse resource locations and production. On approximately 60 GW. For nearly a decade, the primary sources
the demand side, the wider use of electricity in place of other of supply for that grid were wind, thermal, and nuclear power.
energy sources, such as for heating and to power vehicles, More recently, the region has experienced an increase in vari-
also increases the capability of the power grid to interconnect able power supply with a lack of flexible generation. By the end
of 2018, 24 power plants in Northeast China had completed the
more VG.
The main policies and market mechanisms encourage retrofit, creating a regulating capacity of 3.95 GW.
the shift of newly installed VG capacity to Central and
One way to retrofit a coal-fired power plant is to improve
East China from the Three North regions and foster the the boiler and turbine systems to reduce minimum power gen-
participation of VG in various types of market trading. eration output by reducing steam output. This applies to both
The main market solutions include inter-regional spot combined-heat-and-power (CHP) and non-CHP generators.
markets for VG, downward dispatch ancillary service Another way to retrofit is to use electric boilers to decouple the
markets to incentivize downward dispatch of conventional power and heat generation of conventional CHP generators to
generation, and generation rights trading between VG and increase the flexibility of power output. The addition of elec-
tric boilers in the system also increases electricity demand,
consumers' self-supply coal-fired power plants.
With the implementation of these
measures as well as the higher-
than-expected electric de mand
Southwest
Northeast China
growth in recent years, VG cur-
China
Liaoning
Southwest China
tailment has been alleviated sig-
0.02%
Jilin
Sichuan
nificantly since 2017. Both the
Heilongjiang
Chongqing
Northeast
amount of curtailed energy and the
East Inner
Tibet
China
Mongolia
curtailment rate have been reduced,
0.59%
Northwest
while the amount of VG and its
North China
North China
Northwest China
China
0.28%
share in the total energy supply
Beijing
Shaanxi
99.11%
increased (Figure 6). In 2017, the
Tianjin
Gansu
Hebei
Qinghai
installed capacity of VG increased
Shanxi
Ningxia
by 31%, and the curtailed VG de -
Shandong
Xinjiang
creased by 7.4 TWh. The curtail-
ment rate of VG was reduced to
10.4%, 5.2% lower than the rate figure 5. The distribution of solar power curtailment in the SGCC operating areas in 2016.
in 2016. In 2018, the installed VG
capacity increased 22% above
2017 levels, and the curtailed VG
400
18
decreased by 33.2 T W h, which
358.9
15.56%
was 5.8% below 2017 levels. The
16
350
goal for 2019 is to reduce the cur-
293.9
14
14.72%
300
tailment rate of VG to under 5%
12
10.4%
250
of total potential production.
223.8

Installed Capacity of VG (GW)
Curtailment Rate of VG

figure 6. The installed capacity and curtailment rate of VG in China in 2015-2018.
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