Small-scale Power Plants Research Articles

OPTIMASI PENEMPATAN DISTRIBUTED GENERATION PADA PENYULANG GOA LAWAH MENGGUNAKAN METODE PARTICLE SWARM OPTIMIZATION (PSO)

Distributed Generation (DG) is a small-scale power plant located close to the center of load. Goa Lawah feeder is a broadcast that is close to the potential of DG namely the Mini Hydro Power Plant on the Unda River in Klungkung Regency. In this research the optimization of Distributed Generation placement to Goa Lawah feeder. Optimization of Distributed Generation placement aims to reduce the value of loss of power that exist in the feeder Goa Lawah. The results of the research obtained at the point of bus 123 by Distributed Generation placement using Particle Swarm Optimization (PSO) method, with power loss 41 kW (44%). The initial loss before the Distributed Generation interconnection of 72 kW after the Distributed Generation interconnection to 31 kW.

Techno-economic Analysis of Small Scale Electricity Generation from the Lignocellulosic Biomass

In this study, the techno-economic analysis of lignocellulosic biomass conversion to electricity in a small scale power plant was conducted. The proposed process is based on the thermal pathway of electricity production from a carbon content feed. Woods, forest and agricultural residues were considered as the biomass feed, which are available extensively in Iran. Besides, the process benefits not only from the maturity of the method and non-selectivity toward feed but also carbon neutrality and CO2 emission credit income. In order to estimate the minimum selling price (MSP) of the product by this process, the bare module cost model was used. Various equipment sizes were determined by mass and energy balances, whereas the studied power plant capacities were considered 0.5, 1, 5 and 10 MW. The model estimated that the product MSP were 5.83, 4.16, 1.99 and 1.58 ¢/kWh for 0.5, 1, 5 and 10 MW capacities, respectively. Furthermore, a sensitivity analysis was performed to investigate the relative significance of economic parameters on the MSP. The feed, transport, purchased equipment costs and CO2 emission credit income were considered as the sensitivity analysis parameters. Results have proved that the MSP was mainly impacted by the CO2 emission credit income.

Techno-economic evaluation of a biogas-based oxidative coupling of methane process for ethylene production

This contribution is a preliminary techno-economic assessment of a biogas-based oxidative coupling of methane (OCM) process. Biogas is frequently utilized as a renewable energy source within small scale combined heat and power plants or as a natural gas substitute. The activation of methane also enables its utilization as a feedstock to produce chemicals. In this sense, the OCM process allows for the direct conversion of methane into ethylene, which is a major building block for the chemical and polymer industries. Biogas resulting from the anaerobic digestion of vinasse, a liquid effluent from bioethanol industry, is treated for contaminant removal and its methane content is converted into ethylene, which is then purified as the main product. The biogas cleaning process is assessed based on literature data, while an experimentally validated simulation model is used to assess the OCM process. A techno-economic evaluation is then performed through a Monte Carlo simulation, wherein uncertain parameters take random values between reasonable bounds. The net present value results positive in 74% of the cases, indicating that the project is profitable under a wide range of scenarios. Some performance improvement opportunities have been identified and highlighted to guide future studies in the topic.

A biomass small-scale externally fired combined cycle plant for heat and power generation in rural communities

The authors propose a novel small-scale power plant capable of generating electricity and thermal energy from both solid and gaseous biomass, to be employed in rural electrification projects. The proposed system is based on mature and cheap technology, derived from the automotive sector, ensuring very low capital costs and minimum maintenance. The presence of an externally fired gas turbine permits to achieve great fuel flexibility and avoid possible problems of fuel supply in remote and isolated rural communities. The proposed solution makes rural communities capable of achieving energy autonomy targets, following a circular economy paradigm. Three possible configurations have been studied with a thermodynamic analysis in order to estimate system efficiency. Thanks to the reduced fixed and variable costs, the system allows to achieve performances comparable with those of other state-of-the-art technologies usually adopted for rural electrification. A prototype of the proposed system is developed at Politecnico di Bari (LabZERO).

The Operating Strategies of Small-Scale Combined Heat and Power Plants in Liberalized Power Markets

Distributed generation is a good option for future energy systems with respect to sustainable development. In this context, the small-scale combined heat and power (CHP) plants are seen as an efficient way to reduce greenhouse gas emissions due to lower fuel consumption compared to the separate generation of the heat and electricity. The objective of this paper is to establish operating strategies of the small-scale CHP plants to reduce operational cost and increase revenue in liberalized electricity markets. It analyzes a cogeneration plant with organic Rankine cycle and biomass fuel under the conditions of the Romanian electricity market and the green certificates support scheme for electricity generated in high efficiency cogeneration and from renewable sources. The main finding is that choosing an appropriate mode of operation and using correlated prices of heat and electricity can increase the trading profitability of a CHP plant in liberalized power markets. This can be done by an analysis of the particularities and the specific operating conditions of the CHP plant. The results show that the operating strategies of the CHP plant can yield substantial net revenues from electricity and heat sales. The CHP plant can be economically operated to a useful heat load of more than 40% when operating strategies are applied.

Greenough River Solar Farm case study & validation initialization

Large Photovoltaic Solar Power Plants (LPVPPs) and Very Large Photovoltaic Solar Power Plants (VLPVPPs) may have rapid success in the revolutionary change of the national and international power grids to build a 100% renewable power Global Grid. The Australian continent has outstanding solar resource availability, enabling widespread utilization of solar power and power storage technologies (e.g. pumped hydroelectric, thermal, electrochemical). Design and investment modeling of the renewable power grid is the success key for a 100% renewable power grid. The design and investment in LPVPPs and VLPVPPs should preferably be undertaken with the consideration of values such as environmental friendliness, fairness, openness to small private investors, reliability, and accountability. The design of LPVPPs and VLPVPPs should preferably be based on some small-scale PV power plants to help reduce the risks for large to very large investments. Hence, validation and verification efforts of operational PV power plants with different design software are very important for the solar industry. This research paper presents the first specific validation and verification study of the Greenough River Solar Farm (12,68 MWDC, 10,00 MWAC, the first planned expansion to 40,00 MWAC in 2019) near Geraldton in Western Australia with the PVWatts Version 5 model of the National Renewable Energy Laboratory (NREL) System Advisor Model (SAM) Version 2017.9.5. The National Aeronautics and Space Administration (NASA) Modern-Era Retrospective Analysis for Research and Applications Version 2 (MERRA-2) datasets are used as a weather data source in this study. Location and resource, system design data and information on the Greenough River Solar Farm in this study are presumptions based upon publicly available information without any confirmation of power plant owners and operators. The Greenough River Solar Farm NREL SAM software models' are run on 2 different personal computers (PCs) with internet connection for years 2013 to 2017. The results of 6 simple simulations are compared with actual generation data for 2013 through 2017 with some statistical performance measures of the global unique forecast accuracy metrics pool in the Global Grid Prediction Systems (G2PS). The simulations average total time (milliseconds) are 64.1 and 77.9. The best model/actual accuracy measure is 101.9%. The minimum root mean square error (RMSE) is 254.142 MWh in 2013. The maximum RMSE is 414.931 MWh in 2014.

Social Preferences for Small-Scale Solar Photovoltaic Power Plants in South Korea: A Choice Experiment Study

To reduce greenhouse gas emissions, the South Korean government plans to expand the installation of small-scale solar photovoltaic (SPV) power plants, which do not occupy large spaces and have a smaller environmental impact than large-scale SPV power plants. This article applies a choice experiment to evaluate quantitatively the value given by people to the attributes of the installation of small-scale SPV power plants. To reflect the preference heterogeneity of South Korean people, a Bayesian estimation of a mixed-logit model is successfully performed. According to the results, South Korean people consider the electricity bill, the operating body, and the installation location as being more important than other attributes. The respondents prefer small-scale SPV power plants that are located in residential areas, have a large scale of installation, are operated by a private corporation and produce electricity for self-consumption. For these attributes, the South Korean people are willing to pay an additional electricity bill of South Korean won (KRW) 4286/month, KRW 3712/kW, KRW 2885/month and KRW 3731/month, respectively. The results provide meaningful implications regarding the aspects of installation on which the government should focus. In addition, the results can be utilized in policy making and decision making related to the installation of small-scale SPV power plants.

Coupling a small-scale concentrated solar power plant with a single effect thermal desalination system: Analysis of the performance

In this paper, the potential of coupling a small-scale non-imaging focusing heliostat CSP plant with a compact single effect thermal desalination plant is presented and an analytical model for assessing the overall performance is described.The main novelty of this work relies on the study of two small-scale prototype units designed and tested by the authors. More precisely, the system consists of 25 hexagonal non-imaging heliostats for a total reflective area of 9.5 m2 with a peak power output of 6 kWt and of a single stage thermal desalination plant for fresh water production of few hundred liters per day.In order to better evaluate the potential of such a coupling, three different locations in the Mediterranean area have been considered: Palma de Mallorca, Pantelleria and Crendi.The simulation analysis proved interesting results. Compared to electrically driven desalination plant, the performance of the proposed plant is only slightly affected by the salt content of the treated water. In terms of fresh water production, the yearly fresh water production in Crendi is about 60% higher than in Pantelleria because of the higher DNI throughout the year. On the contrary, the maximum daily fresh water production differs to a smaller extent: it reaches a peak of about 70.5 L/day in Pantelleria and 75.0 L/day in Crendi whilst it is always <60 L in Palma.Despite further improvements are needed to reduce the cost of the fresh water produced by similar small-scale CSP desalination plant to overcome the market uptake, the results of the analysis have shown that such a coupling could have a very interesting potential especially for small-scale applications in rural and remote areas where the fresh water demand ranges between 30 L and 60 L per day.

Optimasi Load Frequency Control (LFC) Pada Sistem Pembangkit Listrik Tenaga Mikro Hidro Berbasis PID-ANFIS

Microhydro Power Plant is a small-scale power plant. Microhydro plants are built in areas where there is no power grid.In areas with sufficient water potential to generate electrical energy. The problem that often occurs in the micro-hydro generator system is the occurrence of non-constant generator. This is caused by changes in connected loads. Thus causing frequent fluctuations in the frequency of the system that can cause damage to electrical equipment. Therefore used Load Frequency Control (LFC) in order to control the frequency can be more stable. To get the optimal control parameter in micro hydro power plant system is used an Artificial Intelligence (AI) that is Adaptive Neuro Fuzzy Inference System (ANFIS) method. ANFIS data is taken from PID controller training data. By using PID-ANFIS control method, microhydro generating system can accelerate settling time and minimize overshoot.

Thermodynamic analysis of small-scale externally fired gas turbines and combined cycles using turbo-compound components for energy generation from solid biomass

This paper proposes the implementation of cost-effective commercially available automotive components in small-scale power plants for the energy generation from carbon-neutral biomass. Specifically, a turbocharger and a power turbine of turbo-compound systems are proposed to be coupled with an external combustor and a high temperature heat exchanger in order to obtain a cheap externally fired gas turbine capable of producing about 30 kW of electrical power from the combustion of pruning residues. The externally fired gas turbine cycle can be combined either with a final heat exchanger to generate useful thermal power or with a bottoming cycle to generate useful thermal power and an additional electrical power of about 15 kW. Two plant configurations are proposed for the bottoming cycle: the first is a water Rankine cycle employing the “green steam turbine” as the steam expander, whereas the second is an organic Rankine cycle using an axial turbine and toluene as the working fluid. The results of the simulations, obtained through a detailed thermodynamic model, show that the use of a combined cycle is fundamental to maximize the primary energy savings of the power plant. In the case of negligible pressure losses, the use of a bottoming water Rankine cycle leads to a maximum second law efficiency of about 0.25 and maximum primary energy savings of about 0.23. Instead, a bottoming organic Rankine cycle employing a single stage turbine can increase the second law efficiency and the primary energy savings up to about 0.27 and 0.26, respectively. It is also demonstrated that the use of a two-stage turbine for the organic Rankine cycle can further enhance the plant performance. The effects of the pressure drops in the system are investigated in detail to point out that the minimization of the pressure losses is fundamental to improve the performance parameters of all the proposed configurations.

Modeling and Simulation of Corn Stover Gasifier and Micro-turbine for Power Generation

This paper focuses on modeling the performance of a small-scale combined heat and power (CHP) plant fueled with corn stover pieces (CSP) as very potential biomass resource in Egypt. The developed power plant can be used to satisfy the heat and electricity needs. The proposed power plant performance is simulated using the professional Cycle-Tempo® software. The power plant is divided into three stages; the gasification unit (downdraft fixed bed gasifier and air supply system), gas cleaning and cooling units and the micro-turbine (MT) as an electrical generation unit. In the first stage, the CSP feedstock is converted to producer gas at atmospheric pressure with a reaction temperature about 1028.6 °C, using air as a gasifying agent. The efficiency of gasification process at a regulated air–biomass ratio of 1.5 kg/kg is 77.92% with calorific value (LHV) of 3.87 MJ/kg. Cleaning and cooling stage used to dispose the undesirable gas constitutes such as; tar, flying ash, and etc. The clean gas is passing through the MT as power generator for CHP applications with turbine inlet temperature of 850 °C. Ultimately, the simulation revealed that the CHP overall efficiency of this developed plant is 63.21% providing an electrical power of 94.81 kWel and thermal power of 187.55 kWth.

A small-scale solar Organic Rankine Cycle power plant in Thailand: Three types of non-concentrating solar collectors

Power generation from solar energy is one of many alternative ways to solve the current energy crisis and environmental problems affecting our world. In this study, a system that utilizes low-temperature heat (under 100 °C) from solar energy to generate electricity by a small-scale Organic Rankine Cycle system is proposed. The system is analyzed using three different capacities of the ORC system with R-245fa (20, 40 and 60 kWe) in combination with solar water heating system (SWHS), using four different models (SORC-I, SORC-II, SORC-III, and SORC-IV). Compound parabolic concentrator (CPC), evacuated-tube and flat-plate collectors were used to generate heat with optical efficiency (FR(τα)e) of 0.72, 0.57, 0.74, overall heat transfer coefficient (FRUL) of 0.97, 0.75, 3.62 W/m2-K, and collector area of 2.16, 2.37, 2.08 m2 per unit, respectively. The maximum power output, the CO2 emission, and the economic analysis in terms of levelized cost of electricity (LCOE) were evaluated by a mathematical model. The weather data from Bangkok, a representative city in the central part of Thailand, was used for simulations. The simulation results shown that, if the number of collectors is the same on all systems, the system can produce the highest power output when combined with the CPC collectors. In terms of the economic analysis, the 60 kWe ORC system has the lowest LCOE value of 0.20 USD/kWh if coupled with 950 units of evacuated-tube collectors without initial investment of the collectors into consideration. In this case, the system can produce the power output of 113.5 MWh/Year, and reduce CO2 emission of 62.2 Ton CO2 eq./Year. If investment cost is taken into account, a LCOE of 0.67 USD/kWh can be achieved by the same system but coupled with 900 units of the same collectors. In this case, the system power output is 110.0 MWh/Year, and CO2 emission are reduced by 60.3 Ton CO2 eq./Year.

Dynamic performance investigation of organic Rankine cycle driven by solar energy under cloudy condition

Organic Rankine Cycle (ORC) is promising in utilizing low-medium thermal energy, and solar energy is widely considered as the most attractive renewable energy for the future. Consequently, electricity production by coupling ORC and solar energy can reduce the fossil fuel consumption and lower the CO2 emissions over the world. However, the intensity of solar radiation keeps changing throughout the daytime, so it is important to study the daytime performance of solar-ORC system to guarantee a proper operation.Based on the discretized parameter model built in Dymola, dynamic performances of a small-scale power plant driven by parabolic trough collector (PTC) under clear sky and cloudy sky conditions are analyzed in this paper, respectively. The results show that degree of super heat, evaporation pressure and output power are relevant to direct normal irradiance (DNI) and follow the variation of DNI from morning to afternoon. Particularly, this paper pays attention to analyze the system's responses to the cloud blockage using the dynamic model. It shows that short period (5 min) of cloud blockage of the sun poses no severe influence, while the cloud occurring at morning can cause the system to break down easily. In addition, a conventional PID control strategy is considered for the PTC-ORC system under the weather condition of cloudy sky. The optimized system can generate 105.54 kWh and the system without control can generate 84.95 kWh. The generation can improve 24% compared to the system without control.

Developing a model for improving the productivity and energy production of small-scale power plants using the physical asset management model in a fuzzy environment

The electric power industry today is regarded as the engine of growth and development of other sectors. The technology-based nature of the electric power industry has caused its physical asset to be of particular importance. This study aims to develop a model for increasing the productivity and energy production of small-scale power plants using multi-criteria decision making in fuzzy environments. Productivity of manpower, capital, energy and quality, as the criteria affecting the purpose of the research, and ten activities of the uptime physical asset management model as a solution to meet the goal of the research have been considered. Based on the obtained results, it can be said that teamwork-based methods are the most important strategy for improving the productivity of small-scale power plants. The importance of teamwork is to the extent that other areas of physical asset management fail to function properly without relying on teamwork-based methods. The results of the study indicate that the proposed model is suitable for real-world problems and increases the productivity and uptime at small-scale power plants.

Preliminary Assessment of an Organic Rankine Cycle Power Plant Derived by Linear Fresnel Reflector

Organic Rankine Cycle (ORC) powered by Linear Fresnel Reflector (LFR) is a promising technology to harvest low-grade heat sources to produce electricity. This technology can be very useful especially in remote and arid areas. This work presents the study of a small-scale LFR-ORC power plant installed in Errachidia, Morocco. Simulations are conducted to evaluate the optical behaviour of the LFR based solar field and the thermal performances of the ORC based power block. Nine working fluids were tested in basic and regenerative ORCs. Results showed that the optical efficiency of the LFR changed considerably along the year and it had a great impact on the overall efficiency of the power plant. In what concerns the overall performances of the power plant, cis-butene was found to be the best choice when using a basic ORC in the power block. It allowed to achieve an annual power production of 7.12 kW with an annual overall efficiency of 5.32%. On the other hand, neopentane was found to be the best choice when using regenerative ORC in the power block. It allowed to achieve an annual power production of 7.99 kW with an annual overall efficiency of 5.97%. Regeneration enhanced the performances of the power plant by 12%.

Numerical Model and Performance Validation of a Small-Scale Concentrating Solar Thermal Power Plant in Louisiana

A simplified numerical model of a small-scale (25 - 100 kWe) parabolic concentrating solar power (CSP) plant is presented that can be utilized during the planning stages for a CSP plant, utilizing only simplified information that would be available at the preliminary stages of a project. This is important because existing models currently used for planning purposes, such as the System Advisor Model (SAM) from the National Renewable Energy Laboratory (NREL), do not cover small-scale CSP plants. The model can be used to predict real-time performance, or it can be used with TMY data to estimate annual performance. The model was validated using performance data from an operating small-scale CSP power plant, which is a unique contribution of this work. The results showed that the model correlated well with actual operating measurements for all seasons of the year, and provided a useful tool for planning of future small-scale CSP plants.

Автономные энергоисточники на севере Дальнего Востока: характеристика и направления диверсификации

The paper presents the current state of autonomous energy sources in the north of the Far East. Consideration is given to the capacity structures with a focus on industrial and residential autonomous energy sources. One of the main problems facing power supply to residential consumers in the north of the Far East is the insufficiently developed transport infrastructure, which causes complicated fuel delivery patterns, fuel price rise, and hence high electricity generation cost. The changes in the installed capacity of renewable energy sources (RES) in the north of the Far East are demonstrated for the period between 2011 and 2015. The research shows the main directions of power production diversification in the north of the Far East. The directions include the use of local fuel types, the development of cogeneration, the involvement of renewable energy sources and small-scale nuclear power plants. The paper presents a forecast for the renewable energy development in the north of the Far East up to 2035, made by the authors. The priority RES projects in the off-grid power supply in the north of the Far East are wind and solar power plants

Computational Fluid Dynamic Predictions on Effects of Screw Number on Performance of Single Blade Archimedes Screw Turbine

One of the alternative solutions to reduce the impact of electricity crisis in Aceh and other isolated areas in Indonesia is by the construction of small-scale hydro power plants that can work efficiently on the heads lower than 10 meters. One suitable type of turbine applied to the head below 10 meters is the Archimedes screw turbine. Due to the lack of information about the application of low head power plants, resulting in applications of this type of turbine is still less in Indonesia. This paper examined the appropriate turbine model. Before experimental turbine testing, turbines were designed theoretically first and then analyzed numerically. The flow velocity and pressure patterns within the turbine were analyzed using ANSYS CFD (Computational Fluid Dynamic) software under design conditions for 7, 9 and 11 screw numbers for single blade turbine. Based on the results of pressure analysis, speed and turbulent kinetic energy, it found that turbine performance using 11 blades is better among the three turbines. However, the highest average speed was obtained on the turbine using 7 screws, which maximum pressure obtained on a turbine 7 screws of 1406 Pa, on 9 screws on plane 1301 Pa and at 11 screws of 1175 Pa. Based on the results of the analysis, it showed that the smaller the distance between the channel and turbine blades, the results were more efficient due to the absence of wasted streams. Therefore, the flow pressure in the inlet position all directly leaded to the tip off the blade to produce a momentum.

Study of the wet steam flow in the blade tip rotor linear blade cascade

Experimental investigations of non-equilibrium spontaneous condensation in transonic steam flows in a linear blade cascade were carried out. The cascade consists of the rotor blades of the low-pressure (LP) steam turbine last stage. The experimental testing facility is a part of a small-scale steam power plant located at the Silesian University of Technology in Gliwice. The steam parameters at the testing facility inlet correspond to the wet steam conditions in a low-pressure steam turbine. Static pressure measurements on the blade surface as well as Schlieren images were used to assess the flow field in the steam turbine rotor tip blade linear cascade for different flow conditions. The experimental results were used to validate an in-house CFD code.

Charge and Discharge Analyses of a PCM Storage System Integrated in a High-Temperature Solar Receiver

Solar Dish Micro Gas Turbine (MGT) systems have the potential to become interesting small-scale power plants in off-grid or mini-grid contexts for electricity or poly-generation production. The main challenging component of such systems is the solar receiver which should operate at high temperatures with concentrated solar radiations, which strongly vary with time. This paper deals with the design and the analysis of a novel solar receiver integrated with a short-term storage system based on Phase Change Materials to prevent sudden variations in the maximum temperature of the MGT working fluid. Particularly, the charge and discharge behavior of the storage system was analyzed by means of Computational Fluid Dynamic methods to evaluate the potentiality of the concept and the component capabilities. Achieved results were highly satisfactory: the novel solar receiver has a good thermal inertia and can prevent relevant fluctuations in the working fluid temperature for 20–30 min.