There have been problems with curtailment of renewable energy outputs in China. Many of the country’s wind projects are in remote areas in the north-west, poorly served by grid links. They have sometimes been unable to dispatch their full potential output to users, most of whom are in the major urban areas on the south-east coast. Similar problems have faced some solar projects. Basically, the rush to deploy wind and photovoltaics (PV) overwhelmed the grid system.
One response has been to slow down the deployment rate of wind and PV while grid improvements were made. As I noted in an earlier post, new projects were halted in some areas and capacity caps and quotas imposed, that also being a response to a cost/subsidy overshoot problem caused by the very rapid deployment. The government was forced to suspend all new subsidized solar capacity approvals for a while, after a record 53 GW capacity increase in 2017 left it with a backlog of at least 120 billion yuan ($18 billion) in subsidy payments. So there was a big slowdown.
Necessary action
Clearly something had to be done about the cost overshoot and about curtailment, with a slowdown being an obvious first step. The PV curtailment rate across China had risen 50% in 2015 and 2016, with over 30% of available power in the north-west provinces Gansu and Xinjiang failing to reach the grid. Curtailment of surplus wind output had reached 20% in 2016 nationally and was much more in some remote locations with poor grid links – 43% in worst-case Gansu province. However, there has been progress. Curtailment fell to 33% in Gansu and 15% nationally in 2017. With the slowdown no doubt helping, efforts are now under way to get curtailment down to 30% in the worst locations, Gansu and Xinjiang, and to 20% in Jilin, Heilongjiang and Inner Mongolia. The expectation is that it could be completely eliminated in Heilongjiang, Jilin and Ningxia, while Inner Mongolia is expected to reduce it to below 5%.
In the meantime, the slowdown has helped with the subsidy overspend, as has the fall in cost of PV and wind. In January 2019, China’s National Reform and Development Commission (NRDC) reportedly said that solar construction costs in China had fallen 45% from 2012 to 2017, while wind project costs had dropped 20%. As a result, the subsidy system was being revamped, with some wind and PV projects able to go ahead subsidy-free. Some projects will still get subsidies but the NRDC said “the economic efficiency of projects has steadily increased, creating favourable conditions for state subsidies to retreat and pressures on subsidy funds to ease”.
It seems China’s renewable power capacity will continue to rise. Indeed, by the end of 2018, it had reached 728 GW, up 12% on the year before, according to the National Energy Administration (NEA), and representing 38.3% of China’s total installed power capacity. It included an extra 20 GW of wind and 44 GW of PV. Reuters said “China has tried to change the ‘rhythm’ of renewable power construction to give grid operators time to raise transmission capacity and ensure clean electricity generation is not wasted”. The NEA noted that overall rates of waste in the wind power sector had fallen to 7% in 2018, down five percentage points on the year before, although the major wind generation regions of Xinjiang and Gansu in the far northwest had still failed to get around a fifth of potential wind power onto the grid over the period. There is still a way to go.
More change please
Further improvements are clearly needed. However, looking at it optimistically, a recent report from the US Brookings Institution says “if renewable energy curtailments were to be resolved, then its share in meeting new electricity needs will raise from 37.8% to 63.4%. Similarly, it will increase its share of total electricity generation by 1.6% (from 26.4% to 28.0%)”.
In some ways it’s a little surprising that China has had these problems. With ostensibly high levels of central control China ought, you might think, to have more coherent energy system planning and regional grid co-ordination. However, the reality seems to be that what exists is what has been described as “fragmented authoritarianism”, with rival bureaucratic cliques having conflicting or at least confused jurisdictions. Not too dissimilar from elsewhere perhaps! Though as we have seen, it has had some unwelcome impacts on China’s renewable developments with, for example, edicts coming from central government about building more generation capacity but local regional agencies having responsibility for grids but not always being given the resources to meet them. Clearly, much more needs to be done in terms of national and local grid-strengthening, better project siting and systems design, as well as more integrated planning and institutional policy processes.
Meanwhile, in terms of grid upgrades, one central government priority has been to improve links to the giant 22.4 GW Three Gorges hydro project, which is in the middle of the eastern part of the country, some way from urban centres of power demand on the eastern and southern coast. A series of High Voltage Direct Current (HVDC) links has been built to East and South China, over distances of around 1,000 km, to transfer electricity from the hydro project, and presumably that will also help wind and solar projects in the area. In all, the total capacity of the HVDC links is 7200 MW, with line losses put at about 3%.
Supergrid spread
HVDC links are also being made further afield, from Liaoning, Tianjin and Shandong to Russia and Mongolia. That can help with balancing for China and maybe for other countries in Asia. Given its huge wind, solar and hydro resources, China may at times have some energy to spare for sale, as long as it improves its internal grids, yet at other times the nation may need some balancing inputs. For that, there is abundant wind potential available in Mongolia, where there are also plans for developing large-scale concentrating solar power (CSP) projects in the Gobi Desert. For example, excess power (1 GW’s worth) from the proposed Gobitec CSP project would be exported to urban centres in China, Japan and South Korea via a new network of nearly 4000 km of high-voltage direct current (HVDC) transmission lines.
That could see the creation of an Asian supergrid network, something that Japan in particular, being a series of islands with limited land area for renewable energy projects, may find very helpful. It could also provide useful balancing by linking up renewable inputs across a very wide area at, it is claimed, reasonable cost. As I noted in an earlier post, a variant of this idea, promoted by the Japanese Softbank Group and Japan’s Renewable Energy Institute (REI), is the so-called Golden Ring. Wind energy generated in Mongolia would be transmitted via China and South Korea to Japan, using HVDC links and undersea grid cables, and hydropower from Russia would also be delivered to Japan and other nations. Companies in each region have expressed interest.
That may be some way off but taking it one – big – step on, China has reportedly been looking seriously at the idea of a $50 trillion global grid. But first it must get its internal grids sorted. It is certainly trying with, as I noted earlier, vast cross-county HVDC supergrid links, of which 30,000 km has already been completed. The main aim of supergrid systems is to enhance trade but they would also aid balancing and could reduce the need for local curtailment. Though at a cost. In my next post I look at the somewhat heretical idea that we should accept curtailment since dealing with it will be too expensive.
The above is based in part on material in the new updated and expanded edition of my IOP book Renewables, out later this year.
