On September 22-23, when the Second China Delingha Solar Thermal Conference 2017 was to be held in Delingha, Qinghai Province, the reporter interviewed Sun Rui, vice president of the General Institute of Electric Power Planning and Design, about the issues such as 'the prospect, development bottleneck and solutions of China's solar thermal power industry' and 'the progress of the first 20 solar thermal demonstration projects'. The following is the content of the interview:
Sun Rui, Vice President of the General Institute of Electric Power Planning and Design
Photothermal power generation will play an important role in our country's energy transition
Reporter: At present, our country light heat development present situation how? How about the market space?
Sun Rui: The relevant scientific research institutions and universities in our country have studied the photovoltaic thermal power generation technology from the theory to the experiment for more than 10 years, master its technical characteristics, and lay the foundation for the engineering application; A number of photothermal power generation proprietary technology companies have developed proprietary technology and products with independent intellectual property rights, and have built a number of photothermal power generation test facilities and test projects. Among them, Zhejiang Zhongcong Qinghai Delingha 10MW tower photothermal power Plant has been put into operation since June 2013, and has accumulated rich experience in operation. In addition, there are dozens of projects in the pre-construction work. In September 2016, the previous demonstration project has been approved by the National Energy Administration. The total installed capacity of 20 units is 1.349 million kW, and some projects have started construction.
The Strategy of Energy Production and Consumption Revolution (2016-2030) issued by the National Development and Reform Commission and the Energy Administration (No. [2016]2795) proposes the implementation of leap-forward development of non-fossil energy. By 2030, the proportion of electricity generated by non-fossil energy should reach 50% of the total electricity generation. How to achieve this goal, the specific program is still in the process of research and development. Based on some relevant information, it is roughly estimated that the installed capacity of solar power generation in 2030 May reach 500 million kilowatts, and the installed capacity of solar thermal power generation will occupy a considerable proportion.
According to the statistics of the Wind Energy and Solar Energy Resource Center of China Meteorological Administration, China has about 940,000 km2 of available land with the normal direct solar radiation DNI>1700kWh/m2, and these lands are basically Gobi and desert. If 100,000 square kilometers of land is used to build a solar thermal power plant, the annual generating capacity can reach 5.4 billion kWh, and the total installed capacity is about 1.35 billion kW if the number of generating hours is 4,000.
Reporter: What role does photothermal power play in the power system?
Sun Rui: Through the configuration of heat storage system, the photothermal generator set can maintain stable power output, which is not affected by the change of light intensity. If the capacity of the heat storage system is large enough, the unit can realize 24 hours of continuous power generation. At the same time, compared with coal-fired units, photothermal generating units have shorter start-stop time, lower operating load and better peak regulating performance. They can quickly adjust the output of turbogenerator units according to the needs of power grid load, that is, participate in the primary frequency modulation and secondary frequency modulation of the system. Therefore, the photothermal generator set can be used as the main unit in the power system to bear the base load, and can also be used as the peak regulating unit to bear the peak load. In winter, the wind abandoning power can also be used to store energy for power generation.
Photothermal power generation is not only renewable energy generation itself, but also can improve the capacity of accepting wind power and photovoltaic power generation due to its regulating effect. This is because it replaces coal-fired units in the power system and reduces the small technical output required to run the units in the grid, so its contribution to increasing the share of renewable energy generation is 1.5 times that of installed PV capacity. In addition, it must be emphasized here that if the photothermal generation is used as the peak regulating unit, the principle of not sacrificing the economy of the photothermal generation unit should be taken as the principle.
Reporter: How will future photothermal power be positioned in our energy system? Is it possible to become the dominant energy source?
Sun Rui: Solar energy resources are inexhaustible. Photothermal power generation can provide continuous and reliable power and has good regulating performance. Photothermal power generation can not only replace fossil energy power generation, but also play the role of peak-regulating power station and energy storage power station to improve the power system's capacity to accept wind power and photovoltaic power generation. However, the direct solar radiation resources and available land resources are distributed in the western region of China, and the power consumption space in the western region is limited. When the solar thermal power generation reaches a certain scale, it must rely on long-distance transmission lines to transmit power to the central and eastern regions.
Therefore, photothermal power generation, as one of the renewable energy power generation, will be in synergy with the hydropower, wind power, photovoltaic, biomass power generation and other diversified renewable energy power generation, and play a role in our energy transformation.
The first 20 solar thermal demonstration projects encounter four 'roadblocks'
Reporter: With only one and a half years to go before the completion of the first 20 solar thermal power demonstration projects by the end of 2018, the project progress is not optimistic. What are the main obstacles? How to solve it? Which projects are expected to be completed and put into operation by December 31, 2018?
Sun Rui: The progress of the previous batch of demonstration projects did not meet the expectations, the reasons are many, there are common problems, but also some individual problems, summarized in the following reasons:
First of all, the on-grid electricity price of the first batch of solar thermal power generation demonstration projects approved by the National Development and Reform Commission was 1.15 yuan /kWh, which did not reach the expected return on investment (internal rate of return on capital of 10%) when most projects were declared. Therefore, in the approval document, it stressed that 'relevant local departments are encouraged to adopt measures such as tax cuts, fiscal subsidies, green credit and land concessions for solar thermal power enterprises, so as to promote the development of the solar thermal power industry.' However, judging from the implementation of the previous approved projects, the support measures emphasized in the article have not been implemented. As a result, the low return on investment of some projects poses obstacles to investment decisions, and some projects are likely to be abandoned.
Second, project financing is difficult. Banks have a limited understanding of the photovoltaic power generation, and they are worried that the photovoltaic power generation will suffer from serious light abandonment like the photovoltaic power generation project, which will affect the loan repayment. In addition, banks have strict loan conditions for private enterprise investment projects, and it is difficult to meet the requirements of guarantee and mortgage. As a result, some projects invested by private enterprises have to seek state-owned enterprises as investment partners to solve financing problems, which also delays the progress of the projects.
Third, when the demonstration project was declared, the declaration unit was not fully prepared and the site conditions for the factory were not fully implemented. Later, the site had to be changed, delaying the project progress. In other projects, the way of collecting light and heat was not thoroughly studied, and later they had to be changed, which also delayed the progress of the project. There are also some projects, due to the bidding process complaints, also caused a great impact on the project schedule.
Fourth, the construction cycle of the general solar thermal power generation project needs 24 months, but the winter in the north of our country can not be constructed and installed. So it would take about three years in total to add two winters to the 24 months. Based on this, most projects will not be completed by the end of 2018. From the announcement of demonstration projects in September 2016 to September 2019 is a reasonable construction period.