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China Power Sector For Dummies- Part 1: Grids and Dispatch - Getting Smarter
1/10
First, Chinese doesn't have a national grid, at least not in the way that small countries do. There are 6 regional grids (N, NE, NW, E, C, S). State Grid runs 5 of them and Southern Grid runs 1.
1/10
First, Chinese doesn't have a national grid, at least not in the way that small countries do. There are 6 regional grids (N, NE, NW, E, C, S). State Grid runs 5 of them and Southern Grid runs 1.
2/10
These grids are somewhat interconnected with Ultra High Voltage (UHV) lines. UHV DC lines are used for long-distance connections and UHV AC lines for shorter distances. So power can be moved around the country, but at a cost, and lines have load limits.
These grids are somewhat interconnected with Ultra High Voltage (UHV) lines. UHV DC lines are used for long-distance connections and UHV AC lines for shorter distances. So power can be moved around the country, but at a cost, and lines have load limits.
3/10
The overall balance of China's power sector is indeed of oversupply, but this is not true on a regional basis. The East and South grids specifically have very tight local supply and are net importers of power from other grids. Meanwhile the NW and NE grids have a huge glut.
The overall balance of China's power sector is indeed of oversupply, but this is not true on a regional basis. The East and South grids specifically have very tight local supply and are net importers of power from other grids. Meanwhile the NW and NE grids have a huge glut.
4/10
This power glut is due to renewables, specifically wind in the NE and both wind and solar in the NW. These regions have great natural resources of wind and solar but relatively weak local consumption of power . Even after ex-region export, they still have too much power.
This power glut is due to renewables, specifically wind in the NE and both wind and solar in the NW. These regions have great natural resources of wind and solar but relatively weak local consumption of power . Even after ex-region export, they still have too much power.
5/10
In a perfect economic world, power is purchased by the grid from generators according to marginal cost, and solar/wind power, with a marginal cost near 0, would always get dispatched as long as the sun is shining/wind is blowing. But this doesn't always happen in China.
In a perfect economic world, power is purchased by the grid from generators according to marginal cost, and solar/wind power, with a marginal cost near 0, would always get dispatched as long as the sun is shining/wind is blowing. But this doesn't always happen in China.
6/10
The issue is that some (not all) Chinese provinces follow a quota dispatch policy, whereby all generators are guaranteed a certain number of operating hours in a year. The grid is required to buy power from all the generators equally. Including coal.
The issue is that some (not all) Chinese provinces follow a quota dispatch policy, whereby all generators are guaranteed a certain number of operating hours in a year. The grid is required to buy power from all the generators equally. Including coal.
7/10
When the sun is shining or the wind is blowing, but the grid isn't purchasing their power, that generation is wasted (unless storage is available). This is called curtailment. For several years, it was a major concern for renewable generators and investors in China.
When the sun is shining or the wind is blowing, but the grid isn't purchasing their power, that generation is wasted (unless storage is available). This is called curtailment. For several years, it was a major concern for renewable generators and investors in China.
8/10
From 2016-2019, approvals for new capacity in the NW and NE grids were slashed to help demand catch up to supply and combat curtailment, and it was working.
With reduced power demand in 2020 (COVID), curtailment has returned to some degree, although not as bad as before.
From 2016-2019, approvals for new capacity in the NW and NE grids were slashed to help demand catch up to supply and combat curtailment, and it was working.
With reduced power demand in 2020 (COVID), curtailment has returned to some degree, although not as bad as before.
9/10
Curtailment is much less pronounced in provinces that don't have a generation quota for coal. In these provinces, power is dispatched according to an economic merit order, with the cheapest dispatched first. Expensive generators will theoretically be forced out eventually.
Curtailment is much less pronounced in provinces that don't have a generation quota for coal. In these provinces, power is dispatched according to an economic merit order, with the cheapest dispatched first. Expensive generators will theoretically be forced out eventually.
10/10
China's dispatch protocols will get better as big data is applied in the power sector. While it will always be difficult to compete with the efficiency of small grids like SG, China is well on-track to have the world's 'smartest' LARGE grid within 10 years IMO.
China's dispatch protocols will get better as big data is applied in the power sector. While it will always be difficult to compete with the efficiency of small grids like SG, China is well on-track to have the world's 'smartest' LARGE grid within 10 years IMO.
