MWp Photovoltaic Plant Research Articles

Techno-economic assessment of renewable hydrogen production for mobility: A case study

Renewable hydrogen produced by water electrolysis from intermittent energy sources (i.e. sun and wind) is considered one of the most promising energy carriers for the decarbonisation of the so-called “hard-to-abate” sectors, especially heavy-duty transport and industry. To this reason, several new projects are currently under development and public fundings are widely available to boost the renewable hydrogen market. In this fast-changing scenario, this paper presents the techno-economic analysis of an integrated system where renewable power generation, electrolytic hydrogen production and final hydrogen use are closely integrated within a specific site, allowing higher efficiency as well as a containment of hydrogen production and handling cost. The analysis here presented considers a specific case study that includes a 12.5 MWP photovoltaic plant, a 5 MW electrolyser capable to produce nearly 300 t/yr. of renewable hydrogen, and a compression and storage system, all located in Sardinia (Italy). Differently from previous studies, this work faces the analysis from two opposite perspectives: on the one hand, it allows the assessment of the levelized cost of hydrogen during the whole project’s life, making the results comparable to those from other similar analyses; on the other hand, it presents the calculation of project’s profitability in terms of net present value, internal rate of return and payback time from the perspective of a potential investor. The analysis shows that a whole investment of about 20.3 M€ is required, which allows to achieve a levelised cost of hydrogen of 4.09 €/kg, which can decrease to 2.97 €/kg considering the revenues from selling oxygen and the overproduction of electricity. The potential use of renewable hydrogen in urban public transport (by means of fuel cell electric vehicles) has been considered as well, in comparison with conventional diesel buses. Despite the lower cost for fuel (0.41 €/km for hydrogen buses vs. 0.72 €/km for diesel buses) and maintenance and repair (0.20 €/km vs. 0.27 €/km), as well as the lower CO2 emission (some 76 t/yr. saved per bus), the very high investment cost for hydrogen-fuelled buses (up to 720,000 €) makes hydrogen still not competitive with diesel for urban transport, being hydrogen buses characterised by a whole specific transport cost of 1.45 €/km, to be compared with 1.04 €/km for diesel buses.

Control method to coordinate inverters and batteries for power ramp-rate control in large PV plants: Minimizing energy losses and battery charging stress

This work presents a novel control method for multi-megawatt photovoltaic (PV) plants that is able to regulate each plant inverter and the battery system to mitigate PV power fluctuations. The proposed control method makes it possible to implement different PV ramp-rate control strategies based on the use of batteries and the limitation of inverters during positive fluctuations, which have been conceptually proposed in the specialized bibliography, but have omitted how to perform the coordination between PV generators. The dynamic model and the tuning of the control parameters are presented and the method is used to correctly implement different inverter-limitation strategies using 5-second data from a real 45 MWp PV plant. Furthermore, a new control strategy is proposed. This strategy reduces curtailment losses to negligible values and takes into account and addresses the intrinsic asymmetry in the battery charging and discharging capability, an issue that has been overlooked in the specialized bibliography. The results show that the proposed control method can effectively control each of the multiple inverters in order to obtain the desired PV plant operation to regulate the battery charging power, even during highly fluctuating scenarios.

Improving solar photovoltaic installation energy yield using bifacial modules and tracking systems: An analytical approach

In this paper, we present the results of a simulation of a 3 MWp photovoltaic plant in Nigeria using four case study scenarios: ground-mounted fixed inclined monofacial, and bifacial photovoltaic installation, as well as monofacial and bifacial photovoltaic installations with trackers. The bifacial gains, tracker gains, and bifacial-tracker gains were calculated for each configuration. The fixed ground-mounted inclined bifacial PV system gained 12% annual average bifacial gain over a fixed ground-mounted monofacial system, while the bifacial system with a solar tracker gained 8.9% over a monofacial system with a solar tracker. A monofacial PV system with a tracker over a fixed inclined monofacial system has a tracker gain of 16%, while a bifacial PV system with a tracker over a fixed inclined bifacial system has a tracker gain of 13.2%. The monofacial system with a solar tracker outperforms a fixed inclined bifacial system by about 4%. The sensitivity analysis performed to determine the effect of system parameters such as albedo and ground clearance height on bifacial PV systems reveals that the increase in specific energy production per kilowatt-hour per year is directly proportional to the albedo of the surface area on which the bifacial PV systems are installed, and adequate ground clearance height is required between the ground and the installed bifacial PV plants.

Efficiency Comparison of DC and AC Coupling Solutions for Large-Scale PV+BESS Power Plants

In large-scale photovoltaic (PV) power plants, the integration of a battery energy storage system (BESS) permits a more flexible operation, allowing the plant to support grid stability. In hybrid PV+BESS plants, the storage system can be integrated by using different power conversion system (PCS) layouts and different charge–discharge strategies. In the AC-coupling layout, the BESS is connected to the ac-side of the system through an additional inverter. In the DC-coupling layout, the BESS is connected to the dc-side, with or without a dedicated dc–dc converter, and no additional inverter is needed. Referring to a 288 MWp PV plant with a 275 MWh BESS, this paper compares the PCS efficiency between AC- and DC-coupling solutions. The power injected into the grid is obtained considering providing primary power-frequency regulation services. A charging and discharging strategy of the BESS is proposed to ensure cyclic battery energy shifting. The power flows in the different components of the system that are obtained under realistic operating conditions, and total energy losses and annual average efficiency are calculated accordingly. Finally, results show a higher efficiency of DC-coupling compared to the AC-coupling layout.

Fully solar powered Doncaster Sheffield Airport: Energy evaluation, glare analysis and CO2 mitigation

The solar photovoltaic cells received special attention during the past few years due to their rapid renewability consideration, particularly in international airports because of sustainability and high cost of fossil fuel. The present study aims to evaluate the feasibility performance of a novel 12 MWp capacity solar photovoltaic (PV) power plant at Doncaster Sheffield Airport, UK and to develop a mathematical model to provide a greater understanding of glare from solar panels and subsequently outline methods to avoid its effects. SISIFO and Global Solar Atlas software (GSA) simulations were used to obtain the results. Results reported that the proposed plant produced average energy of 1,034.31 MWh monthly and 12,411.69 MWh annually. The maximum electricity production was observed in May, June, and July as 1,772.71, 1,872.32, and 1,818.25 MWh, with 20.51, 21.67, and 21.04% of Capacity Utilization Factor (CUF), respectively. The average energy yield per month was achieved as 2585.74 kWh/kWp with an average performance ratio of 82.59%. Results also showed that 12 MWp PV plant at DSA reduced an average CO2 emission of 10,562,270 kg (11,642.90 tons) annually. The results revealed that glaring is very unlikely to occur throughout the year; however, winter period produced the lowest trajectory of reflected light. Overall, the proposed solar plant at Doncaster Sheffield airport (DSA) was found to be feasible and generates almost double electricity of overall energy demand (6,951.55 MWh) at Doncaster Sheffield airport. However, it is recommended that the excessive produced energy during summer could be transfer into the national grid, which would be returned during the winter season to facilitate PV plant.

Techno-economic assessment of bifacial photovoltaic and geothermal based multigeneration system for cleaner communities

This study proposes an integrated renewable energy based multigeneration system for fresh water, heating, electricity and fuel requirements of a community with a greenhouse in Gokcebayir, Canakkale, Turkey. Solar and geothermal sources are used as renewable energy resources while sea source is employed in the desalination process to produce fresh water. The bifacial photovoltaic and hydrogen subsystems are integrated to transfer excess daytime photovoltaic electricity to hydrogen gas as an energy storage medium that is employed as hydrogen fuel for hydrogen vehicles and proton-exchange membrane fuel cell for electricity production during the lack of solar radiation. Geothermal energy system is integrated with photovoltaic subsystem and hydrogen subsystem to create more reliable energy system due to its continuous characteristic, and to provide various outputs such as heating via residential heat pump and fresh water via multi effect distillation desalination system. The bifacial photovoltaic modules are employed in two novel arrays which are the top of the greenhouse and an enhanced albedo field 1.3 MWp photovoltaic plant. The pitch distance and height determinations are made specifically for bifacial photovoltaic plant arrays in terms of solar electricity gain. The proposed bifacial photovoltaic plant is analyzed, modeled and integrated with hourly electric load, thermal load and hydrogen subsystem. The proposed system supplies electricity to a community with 150 households and a greenhouse. 1642 MWh annual electricity demand and 485 MWh annual thermal load is met at the 0.058$/kWh levelized cost of energy with 7938 kg annually produced hydrogen and 14551 kg daily fresh water. The proposed system poses 4.29% internal rate of return where 0.21% electricity could not meet due to the insufficient electricity availability especially during winter months at 39°47′N latitude, 26°15′E longitude.

Performance Analysis of Large Scale Grid Connected PV Plants in the MENA Region

This study is an attempt to investigate the potential of electricity production from large scale Photovoltaic (PV) plants in the Middle East and North Africa (MENA) region. For this reason, three different PV plants configurations, with different capacities: 50, 70 and 100 MWp, were selected for simulation under the climate of ten locations in MENA region. Those locations are well distributed in the region and they have a GHI (Global horizontal irradiation) values between 1683,01 and 2445,39 kWh/m2/year. After that, in order to evaluate and benchmark the region’s PV performance and capacity production, the simulation results of the 100 MWp plant were compared with those simulated under the climate of the US and Spain for the same plant configuration. The results show that the average yearly electricity production from the 100 MWp plant in MENA is around 158 GWh/year, while the same configuration produces 155,8 GWh/year and 155,4 GWh/year if installed in Almeria, Spain and Bakersfield California respectively. For MENA region, the annual average performance ratio (PR) and yield factor (Yf) are of 73,2% and 1578,2 KWh/KWp respectively, whereas, those values are of 74,8% and 1555,9KWh/KWp for Spain and of 73,8% and 1555,2 KWh/KWp for the US. Generally, we can say that a 100 MWp PV plant can be a good option if installed in MENA region, and it may have a better performance than the US and southern Spain in some locations.

Studies on PV power plant designing to fulfil the energy demand of small community in Poland

Although the total energy production from fossil fuels in Poland has been decreasing for the past few years, still at least 80% of the total energy consumption derives from coal. To reduce this high consumption rate alternative energy sources should be developed. One of the most promising is photovoltaics. This paper presents modeling studies of large scale PV power plant design to fulfil the electricity needs of a small community located in Poland. Based on the energy demand prognosis and monthly solar radiation data PV power plant capacity and a number of modules were computed. The distance between rows of the modules was also determined to avoid the shadowing effect. System configuration and energy production simulations were carried out using DDS-Cad software. Results of energy calculations were compared with the yearly energy needs of the studied community. Reduction of greenhouse gases emission was estimated. Modeling results show that proposed 3.1 MWp photovoltaic plant can produce enough energy to fulfil the yearly energy demand of the households in the studied area. Moreover, significant reduction of CO2 emission and other gaseous pollutants were observed.

Characteristic analysis of operation curve of energy storage system considering typical weather conditions to suppress photovoltaic power fluctuation

By mining the typical operating curve of an energy storage system, an understanding of the overall characteristics of the charge–discharge power of the system can be attained and a decisive support for the capacity allocation of the system can be provided. This paper proposes a typical operation curve mining algorithm based on a cloud model for the application scenario of using an energy storage system to suppress the power fluctuation of a photovoltaic (PV) power station. The frequency distribution of the charge–discharge power of the energy storage system in a longitudinal time series is decomposed into several cloud models with different granularities. By weighting and summing the expected values of the normal cloud model group, the typical operating curve of the energy storage system is obtained. To analyze the power distribution of the energy storage system and the typical operating curve under six typical weather types, a nonparametric estimation method was adopted to fit the power value distribution and the fitting deviation was calculated. The rationality of the extracted typical operating curve is verified and the capacity of the energy storage system is determined according to the obtained curve. The typical operating curve is used to configure the energy storage capacity of a 40 MWp PV plant and the result is 4.4984 MW·h, i.e., approximately 4.5 MW·h, which represents 11.25% of the installed capacity of the PV plant. This energy storage capacity affords a 95% probability of meeting the daily capacity requirements of the system. This shows that mining the typical operating curve is a valid method for configuring the energy storage capacity of a PV power station. Using the simulation examples, the effectiveness and the correctness of the method proposed in this paper are verified to provide theoretical support for the capacity allocation of energy storage systems. The authors of the article agree to the retraction of the article effective AUGUST 25, 2021.

Dealing with the implementation of ramp-rate control strategies – Challenges and solutions to enable PV plants with energy storage systems to operate correctly

Energy storage systems (ESS) have been widely proposed as a solution for smoothing out photovoltaic (PV) power fluctuations and complying with new regulations that limit the maximum fluctuation over a given period, typically 10%/min, evaluated over a shorter period of time, such as one second. Although ramp-rate control is one of the most used strategies it does require symmetric charge-discharge power capabilities, which most commercially available batteries do not have. This can lead to non-compliance with the regulations and is a problem that has not yet been sufficiently studied. Furthermore, delays in the communication system between the measurement of the actual PV power, the PLC calculation time and the battery converter response time can lead to a failure to comply with the maximum ramp rate limit, bringing to light the need for faster systems. These two problems are addressed herein, and solutions are presented and validated with 1 s experimental data from a 122.4 kWp PV array section coupled to a 100 kW/56 kWh lithium-ion battery within a 1.18 MWp PV plant in northern Spain.

Technical-Financial Comparison between a PV Plant and a CSP Plant

The paper deals with the economic-financial aspects of two typologies of solar energy sources: PhotoVoltaic (PV) plant and Concentrating Solar Power (CSP) plant. The aim of the paper is to analyze the initial costs, the maintenance costs and benefits deriving from both the government economic incentives and the selling of energy between a 40 MWp PV plant and a 40 MW CSP plant. Even if the two plants under test have the same rated power, it results that the produced energy, under the same environmental conditions, is different. This technical aspect influences the business plan, because the government incentives, as well as the selling of energy, are directly related to the produced energy. Finally, initial costs as well as maintenance costs are also different because of the different constitutive components and the operation principle.

Technical-Financial Comparison Between a PV Plant and a CSP Plant

The paper deals with the economic-financial aspects of two typologies of solar energy sources: PhotoVoltaic (PV) plant and Concentrating Solar Power (CSP) plant. The aim of the paper is to analyze the initial costs, the maintenance costs and benefits deriving from both the government economic incentives and the selling of energy between a 40 MWp PV plant and a 40 MW CSP plant. Even if the two plants under test have the same rated power, it results that the produced energy, under the same environmental conditions, is different. This technical aspect influences the business plan, because the government incentives, as well as the selling of energy, are directly related to the produced energy. Finally, initial costs as well as maintenance costs are also different because of the different constitutive components and the operation principle.