Earlier this month China’s Xinjiang region announced that its second batch of market-based renewable energy projects included no less then twelve projects each consisting of 900 MW of photovoltaics and 100 MW of concentrated solar power (CSP). A thirteenth project is to have 1.35 GW of PV capacity and 150 MW of CSP, with most of these CSP plants having 8-hour thermal energy storage capacity, excepting three of the smaller projects, which are 12-hour
That means Xinjiang is building 1.35 GW / 12 GWh of CSP energy storage by 2024, supporting 12.15 GW of photovoltaics – and it is not the only province fostering the technology within China. The provinces of Gansu, Qinghai, and Jilin had already announced a combined 1.3 GW of CSP back in January, likewise consisting of 100 MW projects – and in every case the projects are to be developed by some of China’s largest developers, ranging from Datang to Three Gorges to SPIC to Power China and other big state-owned names.
Together with the 570 MW already commissioned in China thanks to its pilot project fleet, the projects announced across four provinces – and Inner Mongolia is still to come – will put China at a CSP capacity of 3 GW, eclipsing the former market leader Spain, which brought its fleet online between 2008 and 2012 and has been considering a retrofit to add thermal energy storage.
China’s original pilot project fleet was to consist of 1.35 GW across twenty projects, but these were developed by small companies many of which could not secure funding in time to meet the financially-necessary subsidy deadline of end-2020 for commissioning – which is why only 570 MW of that fleet was built. The new business model is as part of China’s monumental “base project” initiative of utility-scale wind-solar-storage complexes, many sited in the north of the country, with some 85 GW currently under construction. In Xinjiang alone the scheme is fostering 27 GW of photovoltaics, 13 GW of wind power, and 7 GW storage – 1.35 GW of CSP, with the rest being batteries. Because the cost of a battery project is directly proportional to duration, CSP has a clear niche of 8-hour up to 16-hour storage, as scaling up storage capacity only requires more pipes, molten salt, and salt tanks.
China’s CSP pilot projects consisted of a wide variety of designs, but in the past two years the market has clearly settled on molten-salt tower designs. Eight fit that description among the eleven projects in the Gansu-Qinghai-Jilin trio with only two being Fresnel and one a beam-down tower. All use molten salt, indicating that lower 400-degree temperatures (as opposed to 565 degrees) is simply not efficient enough for driving a steam turbine to generate electricity – consider that Western CSP companies like Vast Solar and Heliogen are taking things even further to 800 degrees and 1000+ degrees respectively.
It’s interesting that one of the provinces with CSP capacity is to be Jilin, with 200 MW – that is the province directly north of North Korea, and it is mostly a green place not a desert, though it is next to the eastern reaches of the Gobi. Judging by Direct Normal Irradiation and rainfall metrics, if CSP is usable there, then Europe could build some in southern France, not just Spain, Italy and Greece.(By rethinkresearch.biz Andries Wantenaar)