IEEE Power & Energy Magazine - November/December 2015 - 47

to Hunan, and the ±800 kV HVdc project from North
Shanxi to Jiangsu. (See Table 2.)
✔ Establish a mechanism of renewable energy priority dispatch and optimize the procedure of renewable energy dispatch. The optimization of dispatch in
each time interval has been strengthened. Renewable
generation has been included in the annual, monthly,
weekly, and daily generation schedules. Given the
priority of the stable operation of the power grid, the
maintenance arrangements and commitment of conventional generators were coordinated for optimal
performance. The integration of renewable energy
have been given priority. With intraday scheduling,
there is rolling adjustment of all the generation schedules based on the very short term wind and PV forecast (15 min-4 h ahead), maximizing the integration
of renewable energy.
✔ Further decrease the minimum output of thermal
generation and facilitate renewable energy integration locally. Monitoring of CHP generators has been
strengthened in northeast China (see Figure 6). Utilizing the monitoring system, the temperature of the
water supply and return in important urban heating
areas were monitored in real time and the output of
CHP generators adjusted dynamically. Heat storage
during peak load hours and heat utilization during
valley load hours were implemented. With the premise that the heat demand within the province was satisfied, the output of the CHP units was optimized to
maximize the integration of wind power.
✔ Take full advantage of the bulk power grid, and maximize
the use of existing interprovincial transmission during
valley load hours to transport renewable energy. Wind
power and PV energy enterprises have been encouraged
to transport output to other regions by making use of the
electricity trading platform of SGCC. More than 200
wind power and PV power enterprises participated in
interregional electricity trading in 2014 (see Figure 7).

generation integration locally. An initial analysis shows that
1 kW of pumped hydro power station capacity can increase
wind integration by 2.5-3 kW, which shows the significant
benefits of pumped hydro. But compared with wind projects,
the construction period for pumped hydro is eight years or
longer. There have been pumped hydro generation plans in
wind power bases such as Jilin, Heilongjiang, Hebei, and
Shandong to facilitate wind power integration in the Three
North area for many years. But due to the lack of a clear
pricing mechanism, pumped hydro power stations have not
been progressing well. With the issue of the official document by the Chinese government in July 2014, clarifying the
power pricing mechanism for pumped hydro power stations,
the construction of pumped hydro is speeding up. Three new
pumped hydro power stations, with a total capacity of 3.6 GW,
have been under construction since June 2015.

Main Practice of Facilitating
VG Integration in China
Although subject to the constraints of technology and industry management, China's power sector has conducted much
work on the integration of VG.
✔ Increase investment and speed up power grid construction to satisfy renewable energy integration and
interregional transmission requirements as much as
possible. By the end of 2014, the length of transmission lines for renewable energy in the SGCC operation area reached 40,000 km, of which 37,000 km is
for wind and 2,625 km for PVs. The total investment
reached RMB 79.5 billion. As an important action
to fulfil the National Air Pollution Control Plan and
the renewable energy integration requirements in the
Three North area, the ±800 kV high-voltage (HV) dc
line from Hami to Zhengzhou was put into operation
in January 2014. Similar projects under construction
include the ±800 kV HVdc project from Ningdong to
Zhejiang, the 1,000 kV HVac project from Ximeng to
Shandong, the ±800 kV HVdc project from Jiuquan

table 2. HVdc and HVac transmission projects in China for renewable energy transmission.

Type

Capacity
(GW)

Distance
(km)

Coal-Fired
Generation
Capacity (GW)

Wind Capacity
(GW)

PV Capacity
(GW)

Year of
Completion

Hami to
Zhengzhou

±800 kV HVdc

2,210

6.36

1.25

2014

Ningdong to
Zhejiang

±800 kV HVdc

1,720

9.20

3-4

1-2

2016

Ximeng to
Shandong

1,000 kV HVac

730

8.62

TBD

2016

Jiuquan to Hunan

±800 kV HVdc

2,383

2.8

2017

North Shanxi to
Jiangsu

±800 kV HVdc

1,120

TBD

2017

Project (Start
Point-End Point)

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