China's "Whole County PV" programme has been dramatically expanding the use of solar power in rural areas, by building on government, comnmercial, industrial and residential rooftops. However, a large number of dispersed residential PV will have an impact on the power system, and accurately predicting the shortterm power generation of residential PV is a prerequisite for addressing the impact. However, in addition to its original volatility, residential rooftop PV also has the characteristics of small capacity, decentralized and offline operation, together with the lack of accurate meteorological data, making PV power prediction exceptionally complex. Therefore, under the limited data, this paper longitudinally detects similar samples from the previous power data of the residential PV to be predicted,and horizontally collects similar samples from the power data of neighboring residential PV, ultimately jointly realizing two dimensional data expansion, which overcomes the dependence of PV power generation prediction on some key input features to a certain extent. And then a residential PV generation prediction method is proposed based on LSTNet neural network, which has the functions of shortterm local features capture, longterm time series information reinforcement, and cyclical linear component extraction.

The thermal efficiency of the traditional bottomheated solar still is low, and the interfacial evaporation technology can limit the heat to the evaporation interface, and then quickly generate water vapor to realize the efficient utilization of solar energy. In this paper, a composite interface evaporator with carbon nanopowder as photothermal conversion material and coated with polyvinyl alcohol hydrogel was prepared, and on this basis, a singleeffect solar still was designed. In this paper, firstly, the energy distribution in the process of water production in the still is analyzed by theoretical calculation, and it is found that the sunlight reflection on the condensation surface and the heat conduction on the evaporation interface are the two biggest factors leading to the energy loss of the still. Then, by adjusting the wettability of the condensation surface, the light transmittance is improved, and the sunlight reflection is reduced, so that the evaporation interface can receive more solar energy. It was found that the thermal efficiency of the still was increased from 36.1% to 55.4% by adjusting the wettability of the condensing surface; the heat conduction loss of evaporation interface is reduced by optimizing the water supply structure of evaporator. When the proportion of water supply area is 20%, its thermal efficiency is improved to 64.6%. Finally, the water production performance of the still under outdoor practical conditions was tested, and the system operated stably without salt crystallization. The evaporation interface temperature and water production rate change synchronously with the change of irradiation intensity, and the wholeday water production reaches 2.89 kg/m². This study can provide theoretical guidance for the design and performance improvement of solar still.

The pitch Angle is generally set to a fixed value in the design of vertical axis wind airfoil, which leads to the problem that the aerodynamic performance of the airfoil can't be fully utilized. In this paper, a design method of vertical axis wind turbine considering variable pitch Angle is proposed and applied to airfoil optimization. Then, based on the braking cylinder theory, the power coefficient is iteratively calculated, and the maximum power coefficient is directly taken as the objective function, and the profile and pitch Angle distribution are optimized by using genetic algorithm coupled with RFOIL software. Finally, the new airfoil VAWT250 of vertical axis wind turbine is optimized. Compared with the reference airfoil AIR001, the optimization results show that the aerodynamic performance of the new airfoil is significantly improved under both smooth and rough conditions, especially under rough conditions, the maximum lift coefficient and liftdrag ratio are increased by 16.1% and 17.1% respectively. Under rough conditions, the maximum power coefficient of the wind turbine is increased by 6.81% considering the pitch Angle. The results have a certain guiding significance for the optimal design of vertical axis wind turbine airfoil.

Direct drive wind turbine (PMSG) has become the mainstream model and is widely used in power grid because of its superiority, but it is difficult to evaluate the influence of its control parameters on shortcircuit current characteristics due to the lack of quantitative analysis methods. Therefore, the analytic expression of threephase shortcircuit current is obtained by the calculation method of PMSG active current and reactive current through Parker transformation. Based on the trajectory sensitivity method, the influence mechanism of different control parameters on shortcircuit current is quantitatively analyzed from three aspects of generator parameters, voltage drop coefficient and PI parameter, and the parameter with greater sensitivity is selected as the leading parameter. The optimization objective function is constructed to optimize the main control parameters of PMSG short circuit current. Finally, the electromagnetic transient simulation model of PMSG was established on the PSCAD platform to verify and analyze the shortcircuit current characteristics of PMSG and the optimization effect of control parameters. The research results show that the trajectory sensitivity analysis method can quantify the influence of control parameters on shortcircuit current characteristics, and can provide guidance for parameter tuning in practical engineering.

It is of great significance to optimize the planning and layout of new energy power generation projects on the basis of fully comparing the competitiveness of various new energy power generation projects to promote the highquality development of the regional new energy industry. In order to scientifically measure the competitiveness of various new energy power generation projects in the region and analyze the competition pattern of regional new energy power generation projects, this paper constructs a model of niche width, intensity and overlap of regional new energy power generation projects based on the niche theory, and takes the western region of Inner Mongolia as an example, combined with the operation data of new energy power generation projects in 2022, to measure and analyze the ecological niche of wind power and solar power generation projects in each league city. The results show that there is a mismatch between the niche "structure" and the "scale" width of new energy power generation projects in the western region of Inner Mongolia, and it is necessary to continuously optimize the structure and scale of new energy installed capacity in Ulanqab and Bayannur City. The intensity of new energy niche in the "HohhotBaotouOrdosWuha" area is low, and the development of distributed new energy power generation projects should be considered in the future. The ecological niche overlap between Wuhai and other cities in the western region of Inner Mongolia is low, indicating that Wuhai area has strong potential for new energy development. The research results can provide theoretical support for regional new energy planning, and also provide a decisionmaking basis for the project development of energy investment enterprises.

In this paper, a swirl staged burner with pyrolysis volatiles as fuel was designed. The flow field of the burner combustion process was simulated by ANSYS software, and the flow and combustion characteristics of the burner were studied. The results show that the swirling air of the burner effectively breaks up the pyrolysis volatiles, and achieves the effect of sufficient mixing, stable and uniform flow field and temperature field. The edge flow field generated by swirling air reduces the temperature of the inner wall of the burner (up to 815.69 K), slows down the high temperature corrosion of the wall and reduces the formation of NO₂; the NO₄ concentration in the flue gas of the burner is 43.33 mg/m³, which is significantly lower than the standard limit. The content of pyrolysis volatiles at the outlet of the burner is less than 0.2%.

In the article, biochar was prepared from corn stover, and its structure was characterised by Fourier transform infrared spectroscopy, scanning electron microscope and specific surface area tester, and the adsorption performance of biochar on phenol under different conditions was investigated. The results showed that the microstructural integrity of the biochar gradually decreased and the pore size gradually increased with the increase of carbonation temperature, and the surface contained a large number of polar functional groups, which had a good promotion effect on the adsorption of phenol in solution; the best adsorption performance was obtained for the biochar prepared at a carbonation temperature of 600 °C, with water vapour as the ambient gas and corn stover with a particle size of 40 mesh; the best adsorption performance was achieved when the dosage of CSBCW600 was 0.5 g, the reaction temperature was 35 °C, the oscillation frequency was 150 r/min, the adsorption time was 4 h, the initial concentration of phenol was 100 mg/L, and the reaction volume was 50 mL, 99.5% of phenol was removed.

In order to solve the micrositing problem of wind farms under complex terrain, an optimization strategy based on improved discrete state transfer algorithm (RCDSTA) is proposed. Firstly, in order to solve the influence of ground flatness on fan placement, the terrain ruggedness index (TRI) is introduced to quantify the ground flatness numerically, and the points with excessive ruggedness are constrained. Secondly, a wind turbine layout optimization method based on discrete state transition algorithm (DSTA) is proposed to calculate power generation by multiwind downward threedimensional wake superposition, and the DSTA algorithm is improved to reduce the calculation time of fitness value, so as to shorten the calculation time of complex calculation optimization problems and improve the calculation efficiency. Finally, taking a wind farm with complex terrain in Xinjiang, China as an example, the algorithm is compared with the microscopic site selection results of genetic algorithm (GA) and engineering design under the background of the same terrain conditions and objective function. The simulation results show that the discrete state transition algorithm is more effective than the above two methods in providing a reasonable fan layout scheme considering the characteristics of terrain factors.

Reasonably determining the renewable energy quota ratio to maximize the consumption of renewable energy while minimizing the costs for quotaobligated entities is a critical challenge that numerous studies urgently need to address. In this article, the renewable energy quota target suitable for China is analyzed, with the goal of maximizing the interests of market participants, while considering factors such as power source characteristics, market features, and resource attributes. A noncooperative game bilevel optimization model for renewable energy quota ratios is proposed. In this article, the renewable energy quota target suitable for China is analyzed, with the goal of maximizing the interests of market participants, while considering factors such as power source characteristics, market features, and resource attributes. A a noncooperative game bilevel optimization model for renewable energy quota ratios is proposed. Power generators are positioned at the upper level of the model, engaging in noncooperative games with other power generators to determine optimal pricing based on marginal costs for profit maximization. Quotaobligated entities are located at the lower level, adjusting their electricity purchase plans to optimize the reported electricity quantities and prices from power generators, thereby minimizing total electricity procurement costs. The case study analysis demonstrates that the constructed model not only enhances the benefits of market participants but also promotes the consumption of renewable energy.

Aiming at the defects of gap light leakage and surface heat transfer in the use of a glass vacuum tube, in this paper, the glass tube embedded star multifins receiver is used as the concentrating photothermal conversion component of compound parabolic concentrating solar air device, and the air is selected as the heat transfer medium to alleviate the above defects and reduce the sealing requirements of the device and the low temperature burst tube´rate. The influence of the fin shape of the starshaped multifins receiver on the performance of the compound parabolic concentrating solar air device was comparative studied. The influence of different starshaped multifins receiver on the optical performance of the device was simulated and calculated. Based on this, the thermal properties of the device with embedded star sixfins receiver and the star fivefins receiver were tested and analyzed under actual weather conditions. The results show that when a<7.4°, the optical performance of the solar air collector device with star sixfins receiver is better than that of the star fivefins receiver. The average light receiving rate and concentrating efficiency of the former are 98.2% and 76.4% respectively, which are 1.2% and 1.1% higher than those of the latter. In the sunny day, when the air flow rate is 4.0 m/s, the average outlet temperature, maximum instantaneous heat collection and photothermal conversion efficiency of the solar air collector embedded with the star sixfins receiver are 37.0 °C, 896.45 W and 75.31%, respectively, which are 1.37%, 2.80% and 1.93% higher than that of the embedded star fivefins receiver. The testing results can provide a reference for the structural optimization design of the receiver of the compound parabolic concentrating solar air device.