Techno-economic Performance Indicators Research Articles

The role of state-of-charge management in optimal techno-economic battery energy storage sizing for off-grid residential photovoltaic systems

With increased photovoltaic (PV) penetration in residential areas, an off-grid PV system is a sustainable solution to meet the zero net emissions goal by 2050. However, an off-grid PV system has a significant technical issue: low power supply reliability. Typically, battery energy storage (BES) is necessary to overcome the technical issues associated with PV systems. Conventionally, BES is operated to maintain a power balance between generation and load. However, techno-economic feasibility is a crucial aspect of BES adoption. Although BES can effectively support off-grid PV systems, it may not be available when its state-of-charge (SoC) reaches the minimum allowable limit, creating power supply failures (outages). Therefore, this study proposes, for the first time, a BES power control strategy that collaborates with SoC management to improve the reliability of an off-grid residential PV-BES system. A simulation study is performed using a residential load profile from the urban area of Bangkok, Thailand, obtained from the Metropolitan Electricity Authority (MEA). A comparative study is conducted to compare the proposed strategy’s performance with that of the conventional control strategy. Following the comparative study, the role of SoC management in BES sizing is quantitatively illustrated. Moreover, the impacts of SoC management parameter setting (i.e., SoC restoration threshold and maximum SoC restoration power) are evaluated using techno-economic performance indicators. The simulation results reveal that BES power management with SoC management could reduce BES capacity and levelized cost of energy (LCOE) by 28% and 26.28% compared with the conventional strategy.

Techno-economic appraisal of electric vehicle charging stations integrated with on-grid photovoltaics on existing fuel stations: A multicity study framework

The affordable transportation industry has been severely compromised in 2022 as a consequence of the unexpected surge in the price of fossil fuels. By 2050, the transportation industry is forecasted to expand twice, leading to a variety of issues, such as fossil fuel depletion and environmental emissions. As a result, worldwide trend toward electrifying transport, with energy production originating from both traditional and carbon-free sources. Therefore, consumers of electric vehicles require convenient access to the services of charging stations around the country. This research investigates existing fuel station rooftops for the deployment of the grid-connected photovoltaic (GCPV) system electric vehicle charging stations (EVCS), design, and performance analysis of Pakistan's cities. A mathematical model of the GCPV EVCS under consideration has been described. Three cities in Pakistan: Multan, Lahore, and Islamabad-EVCS powered by photovoltaics and the utility grid have been designed and their comparison of the techno-economic performance indicators have been done through System Advisor Model (SAM) software. To comprehend the impact of uncertainty on the functionality of the GCPV EVCS, sensitivity analyses were conducted at all three designated cities in Pakistan. With this strategy, Pakistan will be able to reduce its greenhouse gas emissions to the level required by the Paris Agreement.

Design of ground-mounted grid-connected photovoltaic system with bifacial modules using PVsyst software

Bifacial photovoltaic module has gained significant traction in recent years due to its higher irradiation capture capabilities with cost-effective technology. This paper presents the design, simulation, and techno-economic evaluation of a 45MW fixed-tilt ground-mounted grid-connected photovoltaic system with bifacial photovoltaic modules. The site is located in Sungai Petani, Kedah, Malaysia. The PVsyst 7.2 software was used to design the system by selecting the rating of PV module, inverter and tilt angle of PV modules. In addition, shading and loss calculation, as well as performance evaluation, were also conducted using the software. The simulation of the optimal geometrical parameters had shown an optimal tilt angle of 5°, the pitch of 5.5m and PV array installation height of 1.5m with an albedo value of 0.25. Besides, the performance of system with bifacial and monofacial modules were compared in terms of techno-economic performance indicators. The results showed that the bifacial PV system produces higher energy output with a lower levelized cost of electricity when compared to the system with monofacial PV modules.

Improved techno-economic optimization of an off-grid hybrid solar/wind/gravity energy storage system based on performance indicators

High proportions of energy from solar and wind should be used to transform the electricity system to a renewable energy (RE) system. The intermittency of wind and photovoltaic power production adds a new level of complexity. To balance power demand and supply, energy storage technologies are required to store surplus electricity and generate energy when needed. In this study, a new emerging energy storage system named gravity energy storage (GES) is integrated into large-scale renewable energy plant with an aim to investigate its optimal design and operation while prove its competitiveness compared to battery storage. The novelty of the proposed approach consists of combining energy management strategy and Fmincon interior point method as an optimization algorithm. The proposed model aims to determine a suitable design of a hybrid renewable-gravity energy storage system (RE-GES) and a hybrid renewable-battery energy storage (RE-Battery) considering techno-economic performance indicators; such as loss of power supply probability, life-cycle cost, and levelized cost of energy. The optimal solution with full satisfaction of load demand was employed to illustrate the operation of four scenarios in order to analyze the effect of solar and wind energy proportion on the system cost, storage capacity, and oversupply. Finally, a sensitivity analysis was performed to identify the variables which have the highest impact on the model objective functions. The study demonstrates that the incorporation of hybrid Solar and wind technologies decrease the required energy storage capacity of up to 34.7% and 30% for GES and Battery system, respectively. The results show that, the hybrid PV-wind-GES is the best option in terms of reliability and economic benefits for the considered case study. The optimal solution comprises 418 PV modules, 477 wind turbines with a GES capacity of 15 MWh. The obtained results show that the cost of energy of RE-GES ranges between 0.3 €/kWh and 0.018 €/kWh while it is between 0.25 €/kWh and 0.05€/kWh for RE-Battery.

Techno-economic comparison of optimal design of renewable-battery storage and renewable micro pumped hydro storage power supply systems: A case study in Sweden

In this study, two types of energy storages are integrated,—namely, micro pumped hydro storage (micro-PHS), and battery storage—into small-scale renewable energy systems for assessing efficiency, cost, maturity, and storage duration.Optimal design of standalone renewable-micro PHS and -battery storage systems for a remote area in Sweden is conducted to find the most suitable solution by considering techno-economic performance indicators such as investment cost, life cycle cost, levelized cost of energy, loss of power supply probability, monthly and annual oversupply, and annual ratio of renewable power to supply power. Number of photovoltaic (PV) modules, number of wind turbines (for renewable energy section), installation height of the upper reservoir, volume of reservoir, pipes diameter, depth to diameter ratio of reservoir, turbine capacity, pump capacity (for PHS section), and battery capacity (for battery storage section) constitute the set of design variables and modified non-dominated sorting Genetic Algorithm is employed as the optimization algorithm. The results show that, for the optimal design with the full satisfaction of power demand, the hybrid PV-wind-battery storage system is the best option in terms of economic benefits and reliability, leading to 18.61% lower life cycle cost and 6.12% lower oversupply, compared to the hybrid PV-wind-micro PHS system. However, the design of both hybrid PV-battery storage and PV-micro PHS systems could be considered fully satisfactory designs led to much higher annual oversupply and much higher life cycle cost in comparison with the PV-Wind-battery storage system.

A systematic approach for selecting suitable wave energy converters for potential wave energy farm sites

The ocean covers approximately 70% of the earth's surface and contains an immense source of renewable energy, in terms of ocean waves. However, this resource is unevenly distributed throughout the world, and so, therefore, converting waves into a useful form of energy will require the identification of potential Wave Energy Farm (WEF) locations. This should be undertaken in tandem with selecting an appropriate Wave Energy Converter (WEC), as the characteristics of these devices are critical in capturing the available wave power. Therefore, this paper describes a three-stage systematic approach that was developed and implemented in order to select the most suitable WEC(s) for marine areas identified as optimal for WEFs. As this sector is evolving rapidly, the first stage identified all WECs currently in development and proposed classifying these devices in a practical and meaningful manner. The second stage developed a procedure for identifying generic WEF locations by integrating the multiple dimensions of sustainable development and the technical limitations of the sector, within a geographic information systems framework. Lastly, the third stage incorporates the results from the previous two stages. The devices considered for further analysis were reduced based on commercial viability, whilst the available power was quantified and characterised at each of the optimal WEF sites. Thereafter, appropriate techno-economic performance indicators were identified to rank and determine the optimal device for a specific location.

Advanced power cycles for coal-fired power plants based on calcium looping combustion: A techno-economic feasibility assessment

Carbon capture and storage is crucial to decarbonising the power sector, as no other technology can significantly reduce emissions from fossil fuel power generation systems. Yet, the mature CO2 capture technologies result in net efficiency penalties of at least 7% points. Emerging technologies, such as calcium looping combustion, can reduce the net efficiency penalty to 2.4% points. Further reductions can be achieved by replacing the conventional steam cycle with advanced power cycles. This study aimed to assess the techno-economic feasibility of the coal-fired power plant based on calcium looping combustion with different advanced Brayton cycles. These included single power cycles, such as recompression supercritical CO2, simple supercritical CO2 cycle, and xenon cycle, as well as combined power cycles based on helium, nitrogen and recompression supercritical CO2 cycles. The net efficiency and break-even electricity price, which was estimated using the net present value method, were used as the key techno-economic performance indicators. A parametric study was also conducted to assess the impact of the key thermodynamic parameters. This study showed that the case based on a single recompression supercritical CO2 cycle had the best overall techno-economic performance, while the recompression supercritical CO2 combined cycle case had the best techno-economic performance among combined cycle cases. The former was characterised with a net efficiency of 38.9%, which is higher than that of the reference coal-fired power plant without CO2 capture (38.0%). Such performance was achieved at a break-even electricity price of 71.2 €/MWel,neth, corresponding to a cost of CO2 avoided of 16.3 €/tCO2.

Heat demand peak shaving in urban integrated energy systems by demand side management - A techno-economic and environmental approach

The integration of variable renewable resources and decentralized energy technologies generates the need for a larger flexibility of the energy demand. In order to fully deploy a demand side management approach, synergies between interconnected energy systems have to be systematically implemented.By taking this standpoint, this study proposes a new approach to explore the potential of multi-energy integrated energy systems. This approach is constituted by two main steps, which are (1) the performance simulation of selected energy infrastructures and (2) the estimation of related techno-economic performance indicators. Step (1) expands the work presented in previous literature, by including a novel co-simulation feature. In step (2), the levelized cost of energy and location-dependent emission factors are used as key performance indicators.In this paper, the presented approach is demonstrated by implementing two demand side management options for heat peak demand shaving. A Swedish residential neighborhood is considered as a case study. The first option explores the potential of storing heat in the thermal mass of residential buildings. The proposed strategies lead to a decrease of up to 70% of primary energy consumption, depending on the indoor comfort requirements. The second option estimates the techno-economic feasibility of a new set of scenarios based on the integration of geothermal distributed heat pumps within a district heating network. The district heating scenario is found to be the most techno-economical convenient. Nevertheless, a moderate penetration of distributed heat pumps (around 20%) is shown to have a good trade-off with the reduction of CO2 emissions.

Economic performance assessment of building integrated photovoltaic system with battery energy storage under grid constraints

In this work, a typical South Norwegian house with BIPV system is considered for potential application of on-site battery energy storage. Economic and technical operation performance analysis has revealed that such a system can perform techno-economically much better compared to its counterpart. Techno-economic performance of BIPV system with appropriate energy storage has been evaluated for grid power supply limits with appropriate energy tariff for minimizing the annualized energy cost. It has been assumed that the capital costs associated with PV has been included in the building mortgage and expected that in the near future, the grid power supply limits would be introduced and therefore the BIPV house owner may need to install the battery with additional investments and it may affect the techno-economic performance of the BIPV energy system. It has been observed that during month-wise appropriate grid power supply limits, battery with BIPV system can perform much better through energy throughput compare to other reported scenarios. The correlation analysis has been presented for techno-economic performance indicators and observed that there is a strong correlation among PV energy production and grid energy supply. Correlation analysis among the technical and economic performance indicators may be useful for techno-economic of BIPV system.

Techno-economic assessment of hydrogen production processes based on various natural gas chemical looping systems with carbon capture

Hydrogen is regarded as a promising energy carrier with several key advantages for future low carbon applications (e.g. no greenhouse gas emission at the point of use, higher energy conversion efficiency). This paper is assessing from a techno-economic point of view, three chemical looping processes suitable for hydrogen production generating high purity hydrogen corresponding to 300 MW thermal output, with a carbon capture rate of at least 90%: i) chemical looping hydrogen production (CLH), ii) sorption enhanced reforming (SER), iii) sorption enhanced chemical-looping reforming (SECLR). Key techno-economic performance indicators were evaluated and compared amongst each other and against a conventional natural gas reforming technology without/with carbon capture by chemical gas-liquid absorption using alkanolamines. The results show that CLH using iron-based (i.e. ilmenite) oxygen carrier seems to be the most promising hydrogen production technology amongst the evaluated systems having the highest energy efficiency at CCR>99%, lower operating and maintenance (O&M) costs, with a hydrogen production cost of 41.84 €/MWh compared to 42.43 €/MWh for no capture conventional reforming and 44.58 €/MWh for amine-based capture with 70% CCR, at a CO2 emissions avoidance cost of 19.46 €/tCO2.

Techno-economic feasibility of power to gas–oxy-fuel boiler hybrid system under uncertainty

One of the main challenges associated with utilisation of the renewable energy is the need for energy storage to handle its intermittent nature. Power-to-Gas (PtG) represents a promising option to foster the conversion of renewable electricity into energy carriers that may attend electrical, thermal, or mechanical needs on-demand. This work aimed to incorporate a stochastic approach (Artificial Neural Network combined with Monte Carlo simulations) into the thermodynamic and economic analysis of the PtG process hybridized with an oxy-fuel boiler (modelled in Aspen Plus®). Such approach generated probability density curves for the key techno-economic performance indicators of the PtG process. Results showed that the mean utilisation of electricity from RES, accounting for the chemical energy in SNG and heat from methanators, reached 62.6%. Besides, the probability that the discounted cash flow is positive was estimated to be only 13.4%, under the set of conditions considered in the work. This work also showed that in order to make the mean net present value positive, subsidies of 68 €/MWelh are required (with respect to the electricity consumed by PtG process from RES). This figure is similar to the financial aids received by other technologies in the current economic environment.

Techno-economic assessment of chemical looping reforming of natural gas for hydrogen production and power generation with integrated CO2 capture

The current study presents the techno-economic analysis of the CLR-CC process. The CLR-CC process comprises of chemical looping reforming (CLR) of Natural Gas, water gas shift, CO2 capture and compression, and combined cycle power plant. A 1-D phenomenological model was developed using MATLAB and is used to study the performance of CLR, whereas the remaining part of the process was analysed using commercial software tools like Aspen and Thermoflow. The effect of design conditions in CLR, mainly the air flowrate to the oxidation reactor, oxidation reactor outlet temperature and the steam flowrate to the fuel reactor of CLR, on the overall techno-economic performance of the CLR-CC process is reported. The CH4 conversion in CLR, net electrical efficiency, CO2 avoidance rate and the Levelised Cost of Electricity (LCOE) have been identified as techno-economic performance indicators. For the sensitivity study carried out in this study through 12 cases, the net electrical efficiency of the CLR-CC process varies between 40.0 and 43.4%, whereas the LCOE varies between 75.3 and 144.8 $/MWh, which is highly dependent on the fuel cost and process contingency rates.

Techno-economic assessment of solid–gas thermochemical energy storage systems for solar thermal power applications

Thermochemical energy storage (TCES) systems are a promising alternative to conventional molten salt systems for integration with solar thermal power plants. TCES systems can offer high storage densities and high storage temperatures. Thus, they have the potential to increase the efficiency and reduce the levelized cost of electricity of solar thermal power plants. The present study investigates reacting systems with alkaline carbonates and hydroxides and metal oxides performing redox and chemical looping combustion reactions for their near-term deployment potential. 17 solid–gas TCES systems are identified from the initial set of 21 systems for techno-economic assessment. A quantitative assessment methodology based on techno-economic performance indicators (TPIs) is proposed for the comparative analysis. The techno-economic analysis indicates that energy consumption by auxiliary equipment and the cost of the feedstock are the most important factors affecting the system capital cost. Eight TCES systems are identified as competitive with molten salts in the near term, with an estimated capital cost lower than $25 MJ−1: hydroxide looping with Ca(OH)2/CaO, Sr(OH)2/SrO and Ba(OH)2/BaO; carbonate looping with CaCO3/CaO and SrCO3/SrO; redox with BaO2/BaO and chemical looping combustion with Fe3O4/FeO and NiO/Ni.