Solar power system that provides energy at night to help China stick to climate commitments
Image credit: DT
Increased adoption of Concentrated Solar Power (CSP) in China would go a long way to helping the country stick to its climate change agreements, according to a new study.
While the country already has a significant amount of relatively cheap wind and solar power installed, these forms of electricity generation only deliver power when it is windy or sunny.
By contrast, more expensive CSP can store its solar energy relatively inexpensively and for long durations in order to deliver power at any time, day or night. SP systems generate solar power by using mirrors or lenses to concentrate a large area of sunlight, or solar thermal energy, onto a small area. Electricity is generated when the concentrated light is converted to heat, which drives a heat engine (usually a steam turbine) connected to an electrical power generator.
While not present in all CSP plants, storage capabilities are made possible by using the solar energy to heat molten salt or synthetic oil which can be stored to provide thermal energy at high temperature in insulated tanks. Later the hot molten salt or oil is used in a steam generator to produce steam to generate electricity by steam turbo generator as per requirement.
According to the study from a research team at Beijing’s Tsinghua University, even though it is more expensive, CSP could ultimately prove less costly for a power system with a lot of renewable energy due to its ability to provide energy all day long.
It found that if CSP were substituted for between 5 and 20 per cent of planned PV and wind power in Gansu Province and Qinghai Province it would bring the greatest benefit to power systems operators, reducing curtailment of wind and PV while lowering the operational costs of base load coal generators that must ramp up and down to ameliorate fluctuating generation from solar and wind.
“We have proposed several research studies before about wind and solar, and they have now have raised more interest in CSP, which is still in its first stage of development,” said lead author of the study, Professor Chongqing Kang. “The reason for the interest is that China has set a very aggressive goal for renewable energy and wind and PV are already in fast development.”
The study comes at a time when China is planning to literally double 2018 global CSP deployment of 5 GW by 2020. Following a 1 GW round of 18 demonstration projects, China plans to build 5 GW of CSP.
Some initial targets in the first round of demonstration projects have proven harder to achieve than expected. Several projects dropped out, unable to reach an initial milestone on time. However, the authors are very confident that these growing pains are surmountable, noting CSP has barely begun deployment compared with PV and wind.
“Not all of the parts can be produced by China at this point, so the learning process in the construction process is a little delayed,” Kang said. “They are still learning; development will be faster in the near future.”
According to the latest annual report from Bloomberg New Energy Finance, global investment in clean energy projects rose by 3 per cent globally largely due to the surging solar market in China.