By analyzing the world's best practices, the mining waste dumps can be turned into suitable land for location the renewable and clean energy power plants. There are several advantages that ...characterize these locations: they are characterized by the environmental conditions that are not acceptable for commercial or residential development. Generally, they are located near the existing roads and energy transmission or distribution infrastructure. They can be adequately zoned for renewable energy sources, provide the opportunity for employment in the urban communities and to promote cleaner and more cost-effective energy technologies, reduce the impact of energy systems on the environment (e.g. reduce the emission of harmful gases). As the solar power plants are usually built on large areas, which can lead to the changes in geological and geotechnical conditions along the project site, it is extremely important to design the appropriate geotechnical investigations to reduce or limit the geological uncertainty and determine the suitability of site for construction. In these cases, the geotechnical studies are very complex, striving for a multidisciplinary approach in analyzing the site in question for construction a solar power plant, respecting the current legislation , regulations, norms and standards.
In this paper, the SCOsub.2 Brayton regenerative and recompression cycles are studied and optimized for a next-generation solar power tower under a maximum cycle temperature of over 700 °C. First, a ...steady-state thermodynamic model is developed and validated, and the impacts of different operating parameters on three critical performance indexes, including the cycle thermal efficiency, specific work, and heat storage temperature difference, are analyzed. The results reveal that these performance indexes are influenced by the operating pressures, the SCOsub.2 split ratio, and the effectiveness of the regenerators in complex ways. Subsequently, considering the three performance indexes as the optimization objectives, a triple-objective optimization is carried out to determine the optimal operating variables with the aim of obtaining Pareto solutions for both cycles. The optimization indicates that the regenerative cycle can achieve the maximum heat storage temperature difference and the maximum specific work of 396.4 °C and 180.6 kW·kgsup.−1, respectively, while the recompression cycle can reach the maximum thermal efficiency of 55.95%. Moreover, the optimized maximum and minimum pressure values of both cycles are found to be around 30 MPa and 8.2 MPa, respectively. Additionally, the distributions of the optimized values of the regenerator effectiveness and the SCOsub.2 split ratio show different influences on the performance of the cycles. Therefore, different cycles with different optimized variables should be considered to achieve specific cycle performance. When considering thermal efficiency as the most important performance index, the recompression cycle should be adopted. Meanwhile, its SCOsub.2 split ratio and the regenerator effectiveness should be close to 0.7 and 0.95, respectively. When considering heat storage temperature difference or specific work as the most important performance index, the regenerative cycle should be adopted. Meanwhile, its regenerator effectiveness should be close to 0.75. The results from this study will be helpful for the optimization of superior SCOsub.2 cycles for next-generation solar tower plants.
Among the various renewable energy generation systems, the solar photovoltaic occupies a leading position today due to its simple structure. However, increasing the efficiency of solar photovoltaic ...systems is a highly researched topic. In this study, possible connection failures in maximum power inverters and other failures, which decrease the efficiency in solar power plants, are examined. Furthermore, the possible consequences of these losses and their effects on the performance of solar power plants are explained. Some missing-failure processes were identified and corrected in the field analysis of the solar power plant in Turkey. Detected missing failures include connection failures of solar inverters, incorrect network configuration of camera system, fixing lighting time settings. The inverter string connection failure made during the projecting and assembly phase was eliminated and the maximum output was determined as 584.25 kW after the DC string arrangement. An increase of approximately 10% was achieved in production. In the project and application phase, the connection details of the inverters should be drawn and given to the field application personnel as a full-fledged project. In this way, incorrect connections that are not shown in the project and made in the field are prevented. This ensures that the installed power plant operates more efficiently, and the budgetary payback period of the investments made is shortened.
This paper summarizes Electromagnetic Transient (EMT) simulation studies using PSCAD/EMTDC undertaken to evaluate the capability and suitability of commercially available large scale Grid Forming ...Inverters (GFMI) to dampen oscillations in a real bulk power transmission network. Faults and a range of grid voltage oscillation frequencies are tested on GFMI and synchronous condenser (SC) models using single source equivalent network model and comparisons of transient, post fault and oscillatory rejection tests are presented. A critical credible fault in the West Murray Zone (WMZ) was simulated on a wide‐area EMT model of the Australian National Electricity Market (NEM) to show the effectiveness of GFMI in providing system strength services and improving damping of network sub‐synchronous control interactions (SSCI). Two scenarios were examined: Direct replacement of existing centralized synchronous condensers in the WMZ of the NEM, and a decentralized distribution of GFMI in the transmission network (treated as expansion or repowering solution for existing grid following inverter equipped solar farms). Simulation results show that commercially available GFMI are a viable option for improving system strength in a practical transmission system with a high proportion of Inverter Based Resources (IBR).
The optimization of photovoltaic solar power plants location in Atacama Desert, Chile, is presented in this study. The study considers three objectives: (1) Find sites with the highest solar energy ...potential, (2) determine sites with the least impact on the environment, and (3) locate the areas which produce small social impact. To solve this task, multi-criteria decision analyses (MCDAs) such as analytical hierarchy process and ordered weighted averaging were applied in a GIS environment. In addition, survey results of social impacts were analyzed and included into the decision-making process, including landscape values. The most suitable sites for solar energy projects were found near roads and power lines throughout the study area. Large suitable areas were found also from central valley from Arica and Parinacota to the north edge of Atacama region. In Atacama region, most suitable sites were found in the Andes. On the contrary, Andes were also found to have high environmental values and scenically valuable landscapes. Moderate and low suitability were found on the coast, especially in Atacama region. Factors such as slope and distance to power lines and roads influenced largely the sensitivity analysis. Area of high suitability increased by 15% when distance to roads was excluded and 18% when distance to power lines or slope was removed. MCDA-GIS method was found to be useful and applicable to the optimization of solar power plant locations in northern Chile.
—
In the post-Soviet space, Ukraine has seen intensive development of private solar generation, which is facilitated by the “green” tariff legally introduced in the country on June 2015, which allows ...small private power plants with a capacity of up to 30 kW not only to consume energy for their needs, but also to sell surplus to the centralized network. In the country there is a well-defined algorithm for the relationship between the object of solar generation and the energy supplying organization. The three solar power plants of small capacity that are located in private households in the city of Melitopol’ is the striking example of this interaction. The analysis of the structure of these power plants, the orientation of the photovoltaic panels and their operation allows us to say that the electrotechnical generating equipment of these plants is effectively operated yearround. In the warm season, the consumed electric energy is enough to supply household and communal needs, and sell the surplus into the grid at the “green” tariff. In the cold season, at not all of these private power plants are the surplusses of the energy supplying organizations sold, since most of the electricity they generate is spent on heating the premises and supplying hot water. Today the possibility of increasing the power generation by photovoltaic modules within the framework of the quotas permitted by the “green” law is being considered.
Investigating supercritical natural fluids for efficient and clean energy production has become a trending research topic due to their technical and environmental advantages. However, on account of ...the supercritical operational conditions, using specially-developed components increases manufacturing prices, especially when dealing with solar-powered plants assisted by thermal energy storage (TES) systems. This paper assesses the economic and environmental trends of an integrated supercritical carbon dioxide (s-CO2) solar-powered plant. The system is composed of a packed-bed TES system, a solar field, and a power block while considering conventional backup heating. Transient year-around numerical simulations explore several operational conditions relying on detailed cost and typical meteorological year (TMY) data. Also, the modeling accounts for the system’s environmental sustainability through a penalization cost regarding CO2 emissions due to auxiliary heating. With parametric analyses, the study assesses the compromise solutions minimizing the levelized cost of energy (LCOE). The results revealed the possible feasibility of the integrated system using such a TES technology for s-CO2 and evidenced several venues for further examination. In the end, a sensitivity analysis investigates the influence of the specific costs and TMY data on the LCOE.
A combined approach of computational fluid dynamics, the discrete phase model, and the wall erosion model was used to numerically investigate the hydrodynamics, separation efficiency, and erosion ...rate in cyclone separators for s-COsub.2 solar power plants. Moreover, the results were compared with those for air and COsub.2 as carrier phases. The experimental data from the literature were used to validate the numerical model, and it was observed that the simulated gas velocities and wall erosion rate accurately aligned with the experimental measurements. The numerical results reveal that s-COsub.2 had the largest tangential velocity compared to the other two media; its area-weighted axial velocity of upward flow was the lowest in the middle part of the cyclone body, and varied considerably in the bottom region of the conical section. The particles were all collected at the bottom surface of air and COsub.2, but the separation efficiency of s-COsub.2 was 81.51%, due to the poor distribution of the vortex and short circuit. Finally, the erosion rate distribution and averaged surface erosion rate were also analyzed for the three carrier phases.
PDF
