Solar-Assisted Small Solar Tower Trigeneration Systems

Solar Energy ◽  
2006 ◽  
Author(s):  
R. Buck ◽  
S. Friedmann
Keyword(s):  
Power Systems ◽  
Cost Reduction ◽  
Cooling Power ◽  
Energy Yield ◽  
Absorption Chiller ◽  
Technical Performance ◽  
Receiver Unit ◽  
The Cost ◽  
System Configurations ◽  
System Layout

Solar-hybrid gas turbine power systems offer a high potential for cost reduction of solar power. Such systems were already demonstrated as test systems. For the market introduction of this technology, microturbines in combination with small solar tower plants are a promising option. The combination of a solarized microturbine with an absorption chiller was studied, the results are presented in this paper. The solar-hybrid trigeneration system consists of a small heliostat field, a receiver unit installed on a tower, a modified microturbine and an absorption chiller. The components are described, as well as the required modifications for integration to the complete system. Several absorption chiller models were reviewed. System configurations were assessed for technical performance and cost. For a representative site a system layout was made, using selected industrial components. The annual energy yield in power, cooling and heat was determined. A cost assessment was made to obtain the cost of electricity and cooling power, and eventually additional heat. Various load situations for electric and cooling power were analyzed. The results indicate promising niche applications for the solar-assisted trigeneration of power, heat and cooling. The potential for improvements in the system configuration and the components is discussed, also the next steps towards market introduction of such systems.

Solar-Assisted Small Solar Tower Trigeneration Systems

2007 ◽  
Vol 129 (4) ◽  
pp. 349-354 ◽  
Author(s):  
R. Buck ◽  
S. Friedmann
Keyword(s):  
Power Systems ◽  
Cost Reduction ◽  
Cooling Power ◽  
Energy Yield ◽  
Absorption Chiller ◽  
Technical Performance ◽  
Receiver Unit ◽  
The Cost ◽  
System Configurations ◽  
System Layout

Solar-hybrid gas turbine power systems offer a high potential for cost reduction of solar power. Such systems were already demonstrated as test systems. For the market introduction of this technology, microturbines in combination with small solar tower plants are a promising option. The combination of a solarized microturbine with an absorption chiller was studied; the results are presented in this paper. The solar-hybrid trigeneration system consists of a small heliostat field, a receiver unit installed on a tower, a modified microturbine, and an absorption chiller. The components are described, as well as the required modifications for integration to the complete system. Several absorption chiller models were reviewed. System configurations were assessed for technical performance and cost. For a representative site, a system layout was made, using selected industrial components. The annual energy yield in power, cooling, and heat was determined. A cost assessment was made to obtain the cost of electricity and cooling power, and eventually additional heat. Various load situations for electric and cooling power were analyzed. The results indicate promising niche applications for the solar-assisted trigeneration of power, heat, and cooling. The potential for improvements in the system configuration and the components is discussed, also the next steps toward market introduction of such systems.

scholarly journals Modeling, Analysis and Optimization of Grid-Integrated and Islanded Solar PV Systems for the Ethiopian Residential Sector: Considering an Emerging Utility Tariff Plan for 2021 and Beyond

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3360
Author(s):  
Tefera Mekonnen ◽  
Ramchandra Bhandari ◽  
Venkata Ramayya
Keyword(s):  
Power Systems ◽  
Green Energy ◽  
Sensitivity Analyses ◽  
Solar Pv ◽  
Pv System ◽  
Simulation Tools ◽  
Technical Performance ◽  
Pv Systems ◽  
Cost Of Energy ◽  
The Cost

Currently, difficulties such as the depletion of fossil fuel resources and the associated environmental pollution have driven the rise of other energy systems based on green energy sources. In this research, modeling and a viability study of grid-connected and islanded photovoltaic (PV) power systems for supplying the residential load in Mekelle City, Ethiopia, were carried out considering the country’s emerging utility tariff plan for 2021 and beyond. The technical viability of the proposed supply option was analyzed using PVGIS, PVWatts and HOMER Pro tool, while the economic and environmental optimization aspects were carried out using HOMER Pro. Sensitivity analyses and output comparisons among the three renewable energy simulation tools are presented. The results showed that under the consideration of an incremental electricity tariff plan (up to 2021), the analyzed cost of energy of the grid/PV system is around 12% lower than the utility grid tariff. Moreover, we also found that by taking the continuous global solar PV cost reduction into account, the cost of energy of the modeled islanded operation of solar PV power units totally broke the grid tariff in Ethiopia after 2029 based on the tariff for 2021 and well before with the expected escalation of the grid tariff on an annual basis. The technical performance of the system realized through PVGIS and PVWatts was almost comparable to the HOMER Pro outputs. Thus, this investigation will offer a clear direction to the concerned target groups and policy developers in the evolution of PV power supply options throughout the technically viable locations in the country.

Implementasi Analisis Proses Bisnis Sebagai Upaya Pengurangan Biaya

2019 ◽  
Vol 10 (1) ◽  
pp. 1-27
Author(s):  
Aniek Wijayanti
Keyword(s):  
Business Process ◽  
Cost Reduction ◽  
Process Analysis ◽  
Value Added ◽  
Added Value ◽  
Natural Material ◽  
Management Activity ◽  
Procurement Process ◽  
Material Procurement ◽  
The Cost

Business Process Analysis can be used to eliminate or reduce a waste cost caused by non value added activities that exist in a process. This research aims at evaluating activities carried out in the natural material procurement process in the PT XYZ, calculating the effectiveness of the process cycle, finding a way to improve the process management, and calculating the cost reduction that can achieved by activity management. A case study was the approach of this research. The researcher obtained research data throughout deep interviews with the staff who directly involved in the process, observation, and documentation of natural material procurement. The result of this study show that the effectiveness of the process cycle of natural material procurement in the factory reached as much as 87,1% for the sand material and 72% for the crushed stone. This indicates that the process still carry activities with no added value and still contain ineffective costs. Through the Business Process Mechanism, these non value added activities can be managed so that the process cycle becomes more efficient and cost effectiveness is achieved. The result of the effective cycle calculation after the management activities implementation is 100%. This means that the cost of natural material procurement process has become effective. The result of calculation of the estimated cost reduction as a result of management activity is as much as Rp249.026.635,90 per year.

ANALISIS PENGARUH BIAYA OPERASIONAL PADA PERUSAHAAN PENERBANGAN NASIONAL

2017 ◽  
Vol 1 (2) ◽  
pp. 81-107
Author(s):  
Dheny Biantara
Keyword(s):  
Value Chain ◽  
Cost Efficiency ◽  
Cost Reduction ◽  
Cost Leadership ◽  
Oil Pricing ◽  
The Cost ◽  
Operation Flexibility ◽  
Airline Maintenance

Summarized Indonesian airline executive views on the reason for the cost problem in mayor airline andon the potential areas and measures of cost reduction in airline operation. Present an introductionsurvey where 3 executives from 3 Indonesian airlines were respondent. In the executive opinion the costproblem in mayor Indonesian airline is primarily due to fuel and oil pricing and money currency. Of thevarious function in airline maintenance was seen as least cost efficiency, whereas flight operation wasseen as an area with most potential for cost reduction. Indonesian airline had made route and fleetchanges after the beginning of 2011 to reduce cost, concludes from the analisys result havingprivatization would be an important step towards more efficient airline operation. Flexibility fromIndonesian airline regulatory would be very much welcome and the value chain concept to improveIndonesian airline having competitive adventage and cost leadership differentiation.

Optimal Placement of FACTS Devices for Voltage Stability Improvement with Economic Consideration Using Firefly Algorithm

2019 ◽  
Vol 14 (1) ◽  
pp. 5-11
Author(s):  
S. Rajasekaran ◽  
S. Muralidharan
Keyword(s):  
Power Systems ◽  
Voltage Stability ◽  
Firefly Algorithm ◽  
Transmission System ◽  
Operating Conditions ◽  
Optimal Placement ◽  
Voltage Collapse ◽  
Facts Devices ◽  
The Cost ◽  
Bus System

Background: Increasing power demand forces the power systems to operate at their maximum operating conditions. This leads the power system into voltage instability and causes voltage collapse. To avoid this problem, FACTS devices have been used in power systems to increase system stability with much reduced economical ratings. To achieve this, the FACTS devices must be placed in exact location. This paper presents Firefly Algorithm (FA) based optimization method to locate these devices of exact rating and least cost in the transmission system. Methods: Thyristor Controlled Series Capacitor (TCSC) and Static Var Compensator (SVC) are the FACTS devices used in the proposed methodology to enhance the voltage stability of power systems. Considering two objectives of enhancing the voltage stability of the transmission system and minimizing the cost of the FACTS devices, the optimal ratings and cost were identified for the devices under consideration using Firefly algorithm as an optimization tool. Also, a model study had been done with four different cases such as normal case, line outage case, generator outage case and overloading case (140%) for IEEE 14,30,57 and 118 bus systems. Results: The optimal locations to install SVC and TCSC in IEEE 14, 30, 57 and 118 bus systems were evaluated with minimal L-indices and cost using the proposed Firefly algorithm. From the results, it could be inferred that the cost of installing TCSC in IEEE bus system is slightly higher than SVC.For showing the superiority of Firefly algorithm, the results were compared with the already published research finding where this problem was solved using Genetic algorithm and Particle Swarm Optimization. It was revealed that the proposed firefly algorithm gives better optimum solution in minimizing the L-index values for IEEE 30 Bus system. Conclusion: The optimal placement, rating and cost of installation of TCSC and SVC in standard IEEE bus systems which enhanced the voltage stability were evaluated in this work. The need of the FACTS devices was also tested during the abnormal cases such as line outage case, generator outage case and overloading case (140%) with the proposed Firefly algorithm. Outputs reveal that the recognized placement of SVC and TCSC reduces the probability of voltage collapse and cost of the devices in the transmission lines. The capability of Firefly algorithm was also ensured by comparing its results with the results of other algorithms.

Recent advances in the technologies of connection for panel structures: Design and cost analysis of different solutions with X-shaped dissipative connectors

2016 ◽  
Vol 20 (3) ◽  
pp. 299-315
Author(s):  
Massimo Latour
Keyword(s):  
Finite Element ◽  
Cost Reduction ◽  
Design Criterion ◽  
Classical Solutions ◽  
Finite Element Analyses ◽  
Seismic Damper ◽  
Classical Systems ◽  
Cyclic Behaviour ◽  
Energy Dissipation Capacity ◽  
The Cost

In this work, a recently patented seismic damper to be applied to structures composed by systems of panels is presented. In particular, the article is devoted to characterize the behaviour of the proposed connector by means of an experimental and numerical analysis and to provide some information about the cost of the elements needed to realize the damper, accounting for the manufacturing process. The experimental analysis has regarded five specimens tested under different loading conditions, and it has been used as a term of comparison with the classical systems of connection currently employed in these structures. Afterwards, in the article, a design criterion able to control the capacity and ductility of the device by simply varying the shape of the damper is presented and its accuracy is evaluated by performing finite element analyses. The results of the experimental and finite element analyses are very promising in terms of cyclic behaviour and energy dissipation capacity and reveal that the design of the element can be accurately controlled by means of the proposed approach. Furthermore, the cost estimate has revealed that the proposed damper is also cheaper than the classical solutions with a cost reduction of about 40%.

Reforming Teacher Pension Plans: The Case of Kansas, the 1st Teacher Cash Balance Plan

2021 ◽  
pp. 1-48
Author(s):  
Robert M. Costrell
Keyword(s):  
Cost Reduction ◽  
Pension Plans ◽  
Average Salary ◽  
Cash Balance ◽  
Surface Appearance ◽  
Risky Assets ◽  
Retirement Accounts ◽  
Employer Contribution ◽  
Loaded Structure ◽  
The Cost

Abstract The ongoing crisis in teacher pension funding has led states to consider various reforms in plan design, to replace the traditional benefit formulas, based on years of service and final average salary (FAS). One such design is a cash balance (CB) plan, long deployed in the private sector, and increasingly considered, but rarely yet adopted for teachers. Such plans are structured with individual 401(k)-type retirement accounts, but with guaranteed returns. In this paper I examine how the nation's first CB plan for teachers, in Kansas, has played out for system costs, and the level and distribution of individual benefits, compared to the FAS plan it replaced. My key findings are: (1) employer-funded benefits were modestly reduced, despite the surface appearance of more generous employer contribution matches; (2) more importantly, the cost of the pension guarantee, which is off-the-books under standard actuarial accounting, was reduced quite substantially. In addition, benefits are more equitably distributed between short termers and career teachers than under the back-loaded structure of benefits characteristic of FAS plans. The key to the plan's cost reduction is that the guaranteed return approximates a low-risk market return, considerably lower than the assumed return on risky assets.

Efficient Replacement of Centrifugal With Absorption Chillers Upgrading the Heat Transfer of the Cooling Tower

2001 ◽  
Author(s):  
E. D. Rogdakis ◽  
V. D. Papaefthimiou
Keyword(s):  
Flow Rate ◽  
Cooling Tower ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Double Effect ◽  
Operating Conditions ◽  
Cooling Power ◽  
Absorption Chiller ◽  
Absorption Chillers ◽  
Cooling Water Flow Rate

Abstract It is a general trend today, the old centrifugal machines to be replaced by new absorption machines. The mass flow rate of the cooling water in the centrifugal machines is normally 30% less than that in the two-stage absorption chiller for the same refrigerating capacity. Some absorption chillers manufacturers have updated and improved the double-effect technology increasing the cooling water temperature difference from the typical value of 5.5°C to 7.4°C and reducing the cooling water flow rate by about 30%. Using such a modern double effect absorption unit to replace a centrifugal chiller the same cooling water circuit can be used and the total cost of the retrofit is minimized. In this case a new flow pattern of the cooling tower is developed, and in this paper the design of a new tower fill is predicted taking into account the new factors characterizing the operating conditions and the required performance of the tower. As an example, the operational curves of a modified cooling tower (1500 KW cooling power) used by a 240 RT double-effect absorption chiller are presented.

Gas Turbine Recuperator Technology Advancements

1972 ◽  
Author(s):  
C. F. McDonald
Keyword(s):  
Heat Exchanger ◽  
Power Systems ◽  
Gas Turbine ◽  
Substantial Reduction ◽  
Liquid Fuels ◽  
Cycle Space ◽  
Fuel Savings ◽  
Efficient Heat Transfer ◽  
The Cost ◽  
Turbine Design

Because of intense development in the aircraft gas turbine field over the last 30 years, the fixed boundary recuperator has received much less development attention than the turbomachinery, and is still proving to be the nemesis of the small gas turbine design engineer. For operation on cheap fuel, such as natural gas, the simple cycle-engine is the obvious choice, but where more expensive liquid fuels are to be burned, the economics of gas turbine operation can be substantially improved by incorporating an efficient, reliable recuperator. For many industrial, vehicular, marine, and utility applications it can be shown that the gas turbine is a more attractive prime mover than either the diesel engine or steam turbine. For some military applications the fuel logistics situation shows the recuperative gas turbine to be the most effective power plant. For small nuclear Brayton cycle space power systems the recuperator is an essential component for high overall plant efficiency, and hence reduced thermal rejection to the environment. Data are presented to show that utilization of compact efficient heat transfer surfaces developed primarily for aerospace heat exchangers, can result in a substantial reduction in weight and volume, for industrial, vehicular, marine, and nuclear gas turbine recuperators. With the increase in overall efficiency of the recuperative cycle (depending on the level of thermal effectiveness, and the size and type of plant), the cost of the heat exchanger can often be paid for in fuel savings, after only a few hundred hours of operation. Heat exchanger surface geometries and fabrication techniques, together with specific recuperator sizes for different applications, are presented. Design, performance, structural, manufacturing, and economic aspects of compact heat exchanger technology, as applied to the gas turbine, are discussed in detail, together with projected future trends in this field.

scholarly journals A study on the reliability and performance of solar powered street lighting systems

2017 ◽  
Vol 5 (2) ◽  
pp. 110 ◽  
Author(s):  
Adebayo Fashina ◽  
Salifu Azeko ◽  
Joseph Asare ◽  
Chukwuemeka Ani ◽  
Vitalis Anye ◽  
...  
Keyword(s):  
Performance Indicators ◽  
Performance Ratio ◽  
Energy Yield ◽  
Street Lighting ◽  
Technical Performance ◽  
Humid Environment ◽  
Total Failure ◽  
Lighting Systems ◽  
And Performance ◽  
Solar Powered

This paper presents the results of a study on the reliability and performance of the solar-powered street lighting systems installed at the African University of Science and Technology (AUST) in Nigeria, a hot and humid environment. The technical performance of the systems was studied using the following performance indicators: system energy yield, capture loss, as well as the system performance ratio while the reliability of the systems was examined using a model developed from the findings from the maintenance and fault diagnosis of the systems. The model was used to predict the total failure and survival probability of the systems using the Weibull distribution. The performance evaluation during the monitored period (February 2012 to January 2015) indicated that the performance ratios of the systems vary from 70% to 89% and the energy yields of the systems ranging from 2.87 h/day to 5.57 h/day. The results from the reliability analysis also showed that when the stress concentration factor around the notch between the cable terminals in the charge controller increases, the charge controller will become overheated, which in turn affected other components of the systems. The implications of this study are also discussed for the design and development of future solar-powered street lighting systems.

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