By Dave Elliott
The Chinese National Renewable Energy Centre (CNREC) says China could get 85% of its electricity and 60% of all its primary energy from renewables by 2050, with wind and solar PV both exceeding 2TW of installed capacity by 2040.
The nation certainly seems to be trying to head that way. Under its new 5 year plan it aims to more than double its wind energy capacity (to 250GW), and nearly treble solar capacity (to 160GW), accelerating well ahead of the EU.
Renewables, including hydro, now supply around ten times more electricity than nuclear power in China, with wind power alone generating more than nuclear. By early 2015, the country had over 115GW of grid-connected wind capacity. Some 21GW of this is in Inner Mongolia, and nearly 11GW in the neighboring Gansu Province. And it is continuing to expand – 30GW was added nationally last year, bringing the total to over 145GW.
However, there are grid-related problems with some of this capacity, leading to around 12% of total wind output being curtailed in 2014, rising to 15% in the first half of 2015, and even more for the wind projects in the remoter locations, far from the major urban energy demand centres in the east. In the first half of 2015, curtailment exceeded 43% in the province of Jilin, 31% in Gansu, 28.8% in Xinjiang, and 20% in West Inner Mongolia.
Long distance transmission is obviously an issue, and has been addressed by building 1000km HVDC supergrids for the large hydro projects in the centre of the country. Wind may need some too. But wind projects are much more diffuse than big hydro, and weak local grids are also an issue. The wind boom happened, in response to central government targets, before proper attention was paid to transmission, which was left mostly to poorly resourced local government agencies: see ‘Energy Governance in China’, P Andrews-Speed, Palgrave.
That is now being addressed and CNREC’s detailed roadmap looks in particular at integration issues, stressing the need for flexible supply and demand-side systems and for inter-province grid connections.
With PV solar now also expanding rapidly in China, there is clearly going to be a need for more work on integration. To help, the US National Renewable Energy Labs, along with the Danish Energy Agency, is working with CNREC and other Chinese groups in an interesting collaborative programme supported by the Children’s Investment Fund Foundation. It is looking in detail at integration issues, drawing on US research and practice. Four technical reports have now been produced. The emphasis is on relaying US experience, but they also look at the situation in China. For example, ‘Renewables-Friendly’ Grid Development Strategies: Experience in the United States, Potential Lessons for China notes that, in addition to grid issues, local system inflexibility and management priorities add to the challenge in China. One problem it identifies is ‘the administrative priority given to the operation of combined heat and power (CHP) units so that heat supply to local residents can be guaranteed during the long winter months. As a result, thermal units often displace wind generation. Additionally, the winter demand for heat reduces the ability of CHP units to ramp down, making variable generation (VG) integration more difficult’.
CHP is valuable in itself, as a low carbon local heat source, but also as a way to balance power use against changes in demand and renewable supply. Similar conflicts have emerged in the EU, in Denmark and Germany especially, although, in that case, CHP/District heating projects are being squeezed out of the energy market by cheaper wind power. Support measures may have to be adopted to limit that. Clearly establishing and then managing the right mix of systems will be hard.
There are also wider issues. The NREL report adds ‘China does not have an organized, actively traded electricity market. The annual amount of inter-provincial power transmission is determined administratively each year by the local governments involved. Fuel prices are also administered and change very slowly […]. Unit commitment is not done on the basis of economic merit. Rather, schedules are set yearly, monthly, and weekly in a hierarchical manner from national, regional, and provincial to county and municipal levels. Traditionally, managing generator schedules focuses on making steady progress towards yearly contracts and administratively allocating generation hours among several power plants’.
However, measures promulgated in 2007 started China on a path toward an ‘energy saving dispatch’ approach, and NREL say that ‘in early 2015, China embarked on a new round of power sector reform, with goals to increase the use of market mechanisms for ancillary services, direct electricity sales, and demand-side management programs’. It may take a while to introduce the sort of market competition the US has, and not everyone will see that as ideal! But NREL’s report provides some technical guidance on how grids can be managed flexibly, which may be very helpful.
The other three reports may also be helpful. Certainly they provide a useful overview of research and experience in the US. One looks at Historical and current US strategies for boosting Distributed Generation. Another looks at Advancing System Flexibility for High Penetration Renewable Integration and is a mine of information on current US thinking on smart grids, demand management and the like. The other looks at Electricity Capacity Expansion Modeling, Analysis, and Visualization: A Summary of Selected High-Renewable Modeling Experiences. It focuses on NREL’s experience with capacity expansion modeling, including mention of the NREL’s 80% high renewable 2050 model. But, for comparison, it does also include data from the China Renewable Energy Analysis Model-Electricity and District Heating Optimization (CREAM-EDO) with high renewables penetration. Quite amazing – rapid acceleration of renewables means that carbon emissions peak at around 2025, well ahead of current targets. Hopefully the US-China collaborative programme will help that happen.
China is clearly leading the renewables race in terms of installed capacity, and is well ahead of every other country in wind power – e.g. the US is only at 74GW. While it is doing less well on integration, technical collaboration with the US may help. Though it has to be remembered that the US and China are in competition for markets. So not all Sino-US interactions in this field are so positive: see this case study of the EU-China solar panel anti-dumping dispute.
The situations in China and the US obviously differ. China is pushing renewables harder. But there are also some similarities: for example, both now need to develop long distance supergrid transmission, as well as local smart grid demand management. It will be interesting to see how they get on, separately – and together.