Can energy storage make off-grid photovoltaic hydrogen production system more economical?

Under the ambitious goal of carbon neutralization,photovoltaic(PV)-driven electrolytic hydrogen(PVEH)production is emerging as a promising approach to reduce carbon emission.Considering the intermittence and variability of PV power generation,the deployment of battery energy storage can smoothen the power output.However,the investment cost of battery energy storage is pertinent to non-negligible expenses.Thus,the installation of energy-storage equipment in a PVEH system is a complex trade-off problem.The primary goals of this study are to compare the engineering economics of PVEH systems with and without energy storage,and to explore time nodes when the cost of the former scenario can compete with the latter by factoring the technology learning curve.The levelized cost of hydrogen(LCOH)is a widely used economic indicator.Represented by seven areas in seven regions of China,results show that the LCOH with and without energy storage is approximately 22.23 and 20.59 yuan/kg in 2020,respectively.In addition,as technology costs drop,the LCOH of a PVEH system with energy storage will be less than that without energy storage in 2030.

Economic analysis of hydrogen production from China’s province-level power grid considering carbon emissions

Hydrogen energy contributes to China’s carbon peaking and carbon neutralization by serving as an important energy carrier.However,the calculation of the cost of hydrogen production by the power grid ignores the current cost of carbon emissions.To measure the cost of hydrogen-production projects in various provinces more comprehensively and accurately,this study incorporates the carbon-emission cost into the traditional levelized cost of hydrogen model.An analysis of the energy structure of the power supply is conducted in each province of China to calculate carbon-emission costs,which are then subjected to a sensitivity test.Based on the results,the carbon-emission costs for hydrogen in each province are between 0.198 and 1.307 CNY/kg,and the levelized cost of hydrogen based on carbon-emission costs varies from 24.813 to 48.020 CNY/kg;in addition,carbon-emission costs range from 0.61%to 3.4%of the total costs.The results also show that the levelized cost of hydrogen considering carbon-emission costs in the Shanghai municipality specifically is most sensitive to the carbon-emission price,changing by 0.131 CNY/kg for every 10%fluctuation in the carbon-emission price.

Modeling and configuration optimization of the rooftop photovoltaic with electric-hydrogen-thermal hybrid storage system for zero-energy buildings:Consider a cumulative seasonal effect

Rooftop photovoltaic(PV)systems are represented as projected technology to achieve net-zero energy building(NEZB).In this research,a novel energy structure based on rooftop PV with electric-hydrogen-thermal hybrid energy storage is analyzed and optimized to provide electricity and heating load of residential buildings.First,the mathematical model,constraints,objective function,and evaluation indicators are given.Then,the simulation is conducted under the stand-alone condition.The annual return on investment and the levelized cost of energy of the system are 36.37%and 0.1016$/kWh,respectively.Residential building with the proposed system decreases annual carbon emission by 25.5 t.In the third part,simulation analysis under different grid-connected modes shows that building system will obtain better economics when connected to the grid,but the low-carbon performance will be reduced.Finally,the cumulative seasonal impact of the countywide rooftop PV buildings is discussed.The result indicates that the energy structure proposed in this paper can effectively reduce the grid-connected impact on the local grid.This model and optimization method developed in this paper is applicable to different climate zones and can provide management support to the investors of NZEB before the field test.

Investment risk evaluation of inland floating photovoltaic power plants in China using the HFLTS-TFN method

Inland floating photovoltaic power plants(IFPPPs)are the key to making full use of water advantages to develop solar resources in the future.Identifying the investment risk is an important prerequisite for promoting the projects on a large scale.This paper proposes a model to assess the investment risk of IFPPPs in China.First,this paper identifies the investment risk factors and establishes an evaluation indicator system from four aspects.Second,the indicator data are collected and described by adopting hesitant fuzzy linguistic term sets and triangular fuzzy numbers to ensure soundness and completeness.Third,a weighted method combining the best-worst method and the entropy method are utilized to determine the indicator weights under the consideration of the impact of subjective preferences and objective fairness.Fourth,the results show that the overall risk level of China’s IFPPPs is‘medium low’.Fifth,sensitivity analysis and comparative analysis are implemented to examine the stability of the evaluation results.Finally,this paper also provides some risk-response strategies for the development of China’s IFPPPs from economy,society,technology and environment.