November 10th has passed for some time; however, to all colleagues in concentrating solar power industry, the fire burned by the initiation of concentrating solar power demonstration project is still raging. At the initiation of National Energy Administration concentrating solar power demonstration project, the applicants, techniques, scales, locations and prices attract attention of the whole industry. Among all these, feed-in tariff earns most. Trying to figure out a reasonable electricity price is no less than testifying Goldbach's conjecture, which needs effort of thousands people, billions of cash and years of time.
Let’s first review a report together: in May 2013, authorized by National Energy Administration, China National Solar Thermal Energy Alliance and other organizations compiled 《China solar thermal power policy research report》jointly. Based on a case of a 50MW parabolic trough solar power plant, the report calculated and analyzed its LCOE. The case parabolic trough plant locates in Inner Mongolia Erdos region; and its detailed technical parameters are displayed below:
Technical parameters setting of a 50MW parabolic trough solar power plant
|
Items |
Technical parameters |
|
Capacity(MW) |
50 |
|
Location |
39°36' N, 109° 46' E |
|
Technical type |
Parabolic trough |
|
Solar field area |
500,000 m2 |
|
DNI |
1,900 kWh/m2yr |
|
Annual average air temperature |
7.4℃ |
|
HTF Temperature (oil) |
393℃ |
|
Cooling way of turbine |
direct air cooling |
|
Turbine rated inlet temperature |
383℃ |
|
Lower T. limit of HTF |
60℃ |
|
Oil temperature at starting point |
60℃ |
|
Efficiency of oil/water evaporator |
96% |
|
Thermal efficiency of turbine generator unit |
35% |
|
Ratio of operation during daytime |
83% |
|
Construction period |
2 years |
|
Capacity factor |
31.7% |
|
Auxiliary fuel for preheat and antifreeze |
Natural gas |
|
Annual electricity production |
138,700,000 kWh |
|
Annual self-power consumption( as 10% of production) |
13,870,000 kWh |
|
Annual on-grid power |
124,304,096 kWh |
|
Data from Institute of Electrical Engineering, Chinese Academy of Sciences, China Power Engineering Consulting Group Co., Ltd, Electric Power Planning and Design Institute |
|
Based on the assumption of financing conditions, and assuming the case plant enjoys the same government preferential policies as other renewable energy technologies: income tax, discount of value added tax, fixed assets depreciation and so on, if the average annual inflation rate during the operation period stays stable, based on the solar resource of the site, plant capacity allocation(power plant capacity factor and average annual on-grid energy), cost of investment, cost of operation and maintenance and financing cost, the report calculated out the plant’s LCOE as 1.38 yuan/kWh.
After two years, among all the concentrating solar power demonstration project applications organized by the National Energy Administration, the applied feed-in tariff most lies in between 1.20 yuan/kWh and 1.30 yuan / kWh. According to each applied feed-in tariff from initiation meeting, counted based on technical route, the average feed-in tariff applied for parabolic trough project is 1.246089 yuan/kWh; for solar tower project is 1.239914 yuan/kWh; for dish-type project is 1.248675 yuan/kWh; and for Fresnel-type is 1.206657 yuan/kWh.
Besides, according to the electricity price forecast voting launched by an industrial media through WeChat platform, the expectations of the final electricity price centralize in 1.2 yuan/kWh, and over a half of the voters thought it would be higher than 1.2 yuan/kWh.
As the first concentrating solar power project with an approved feed-in tariff of 1.2 yuan/kWh, Mr. Jianxiang Jin, the director of SUPCON Co., Ltd, says, “from my part, it is appropriate to fix the price at 1.2 yuan/kWh. The first phase of solar thermal power plant in Delingha only has a capacity of 10MW; the scale is relatively small, plus other research investment and waste. Thus, the approved feed-in tariff of 1.2 yuan/kWh was in fact slightly low. However, right now, required capacity for CSP demonstration projects is required as no less than 50MW, the scale has been enlarged, and the cost of each kilowatt will drop, meanwhile, solar-power efficiency will increase, the price at 1.2 yuan/kWh can make a profit, so it’s appropriate to fix the feed-in tariff at 1.2 yuan/kWh.”
Lixin Zhou, general manager of Commerce Department of Tianjin Binhai Solar Thermal Power Investment Co., Ltd, believes that compared with most countries, northwestern part of China does not have high quality of solar radiation resources; moreover, these areas locate in alpine area, there is a lot of wind and sand. Owing to this, the efficiency of heat collector is lower compared with that of America and South Africa. And we are inexperienced in system integration. For example, Siemens spent nearly two years in solar field and system testing for their first concentrating solar power project in Spain. The commissioning time of solar tower project (e.g. Tonapah and Ivanpah) is longer than expected, the output of plant failed to meet up expectation. Like some parabolic trough reflector factory, it takes at least a year from operation to mass production. Thus, the testing/commissioning period of solar field or heliostats field is longer than most projects. In order to encourage the development of CSP industry, the first CSP project not only needs a high electricity price, but also should be granted a reasonable construction preparation time. Without preparation and land formation, it is hard to start up before September of next year and put it into operation at the end of 2017. All the energy for solar power generation comes from the solar field, whatever parabolic trough plant or solar tower plant, one 50MW project with thermal storage covers at least 2km2 area, it’s better to set aside of enough time.”
If leave out the factor of inflows with low interest from the capital market, the feed-in tariff suitable for this group of demonstration projects shall be between 1.25-1.28yuan/kWh, said Zhifeng Wang, after all, there exists a lot uncertain technical demonstration project.
Zhipeng Liang, deputy director of New and Renewable Energy Department of the National Energy Administration, says that, the feed-in tariff policy for the first group of CSP demo plants hasn’t been decided and the applied price might not be the final. The final feed-in tariff will be evaluated by the pricing division of the National Development and Reform Commission (NDRC) based on the proposal of the National Energy Administration. There will be a possibility that the approved electricity price is lower than the applied one, and the applicants should give a commitment on whether do it or not, which is also one feature of the project evaluation. The applicants also need check in time, if not satisfied with the approved electricity price; the applicant could quit and be replaced by other applicants.
Initial investment, annual direct normal irradiation(DNI) of location, scale of heat storage, size of the plant, technical route and price of the land, all have an impact on the cost of concentrating solar power generation. Combining with practice and rational analysis, the final interval of feed-in tariff might be between 1.2-1.3 yuan/kWh.
The reasonable price of this group of CSP projects can not be known until three years after the plant gets constructed, i.e. year of 2020. No matter the prediction is optimistic or pessimistic, it is only estimation. But for the project being in exploration, it is much better to overweigh pessimistic factors while formulate the feed-in tariff. (Translated by Zhaorui Yang)
