Estimating Long Term Major Maintenance and Capital Spending Requirements of Trinidad’s Aging Power Plants

Author(s):  
Robert R. Richwine ◽  
Michael Joseph ◽  
Charles Huguenard ◽  
Hafeez Baksh ◽  
Mike Elenbass

This paper describes the process used by the Power Generation Company of Trinidad and Tobago (PowerGen) to estimate the range of major (expenditures greater than US$50,000) recurring and non-recurring costs that can be expected to be incurred from 2006–2025 by PowerGen’s three existing generating facilities: Port of Spain, Point Lisas and Penal. Since many of these Capital and O&M costs are not 100% certain, a probabilistic approach was used that incorporates a Monte Carlo methodology. The results of this approach allowed PowerGen to better understand the range of possible major capital and O&M expenditures that would likely be required over the next 20 years along with a quantification of the risk profile of those ranges. By adding these costs to the routine O&M costs, a total cost cash flow timeline was able to be developed that more realistically forecast the actual financial requirements of PowerGen’s power plants. Periodic review and updates of the data will also provide PowerGen with a continuing sound basis for long term technical and financial decisions. Additionally, a benchmarking analysis was performed that compared the reliability trends of similar but older technologies to those plants in PowerGen’s fleet in order to gain an insight into the reliability expectations for PowerGen plants over the next twenty years.

Author(s):  
M. D. Pandey ◽  
M. I. Jyrkama

As existing fleets of nuclear power plants continue to seek long term operation, aging management programs have been developed to mitigate the effects of degradation processes affecting reactor components that are important to safety and generation. Inspection programs are an integral part of aging management, as they provide crucial information to determine the scope of maintenance and replacement programs and guide investment planning of life extension projects. This paper presents a probabilistic framework for calibrating the sample size of a periodic inspection program with the goals of the aging management program, such as limiting the number of potential substandard components below a reasonable threshold.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 951-958
Author(s):  
Tianhao Liu ◽  
Yu Jin ◽  
Cuixiang Pei ◽  
Jie Han ◽  
Zhenmao Chen

Small-diameter tubes that are widely used in petroleum industries and power plants experience corrosion during long-term services. In this paper, a compact inserted guided-wave EMAT with a pulsed electromagnet is proposed for small-diameter tube inspection. The proposed transducer is noncontact, compact with high signal-to-noise ratio and unattractive to ferromagnetic tubes. The proposed EMAT is designed with coils-only configuration, which consists of a pulsed electromagnet and a meander pulser/receiver coil. Both the numerical simulation and experimental results validate its feasibility on generating and receiving L(0,2) mode guided wave. The parameters for driving the proposed EMAT are optimized by performance testing. Finally, feasibility on quantification evaluation for corrosion defects was verified by experiments.


2015 ◽  
Vol 12 (1) ◽  
pp. 1-12
Author(s):  
Sarah Hackett

Drawing upon a collection of oral history interviews, this paper offers an insight into entrepreneurial and residential patterns and behaviour amongst Turkish Muslims in the German city of Bremen. The academic literature has traditionally argued that Turkish migrants in Germany have been pushed into self-employment, low-quality housing and segregated neighbourhoods as a result of discrimination, and poor employment and housing opportunities. Yet the interviews reveal the extent to which Bremen’s Turkish Muslims’ performances and experiences have overwhelmingly been the consequences of personal choices and ambitions. For many of the city’s Turkish Muslim entrepreneurs, self-employment had been a long-term objective, and they have succeeded in establishing and running their businesses in the manner they choose with regards to location and clientele, for example. Similarly, interviewees stressed the way in which they were able to shape their housing experiences by opting which districts of the city to live in and by purchasing property. On the whole, they perceive their entrepreneurial and residential practices as both consequences and mediums of success, integration and a loyalty to the city of Bremen. The findings are contextualised within the wider debate regarding the long-term legacy of Germany’s post-war guest-worker system and its position as a “country of immigration”.


Author(s):  
Sally Treloyn ◽  
Matthew Dembal Martin ◽  
Rona Goonginda Charles

Repatriation has become almost ubiquitous in ethnomusicological research on Australian Indigenous song. This article provides insights into processes of a repatriation-centered song revitalization project in the Kimberley, northwest Australia. Authored by an ethnomusicologist and two members of the Ngarinyin cultural heritage community, the article provides firsthand accounts of the early phases of a long-term repatriation-centered project referred to locally as the Junba Project. The authors provide a sample of narratives and dialogues that deliver insight into experiences of the work of identifying recordings “in the archive” and cultural negotiation and use of recordings “on Country.” The entanglement of local epistemological frameworks with past and present collection, archival research, repatriation, and dissemination for intergenerational knowledge transmission between spirits, Country, and the living, is explored, showing how recordings move song knowledge from community to archive to community and from generation to generation, and move people in present-day communities. The chapter considers how these “moving songs” allow an interrogation of the fraught endeavor of intercultural collaboration in the pursuit of revitalizing Indigenous song traditions. It positions repatriation as a method that can support intergenerational knowledge transmission and as a method to consider past and present intercultural relationships within research projects and between cultural heritage communities and collecting institutions.


2021 ◽  
pp. 002224372110092
Author(s):  
Zhenling Jiang ◽  
Dennis J. Zhang ◽  
Tat Chan

This paper studies how receiving a bonus changes the consumers’ demand for auto loans and the risk of future delinquency. Unlike traditional consumer products, auto loans have a long-term impact on consumers’ financial state because of the monthly payment obligation. Using a large consumer panel data set of credit and employment information, the authors find that receiving a bonus increases auto loan demand by 21 percent. These loans, however, are associated with higher risk, as the delinquency rate increases by 18.5 −31.4 percent depending on different measures. In contrast, an increase in consumers’ base salary will increase the demand for auto loans but not the delinquency. By comparing consumers with bonuses with those without bonuses, the authors find that bonus payments lead to both demand expansion and demand shifting on auto loans. The empirical findings help shed light on how consumers make financial decisions and have important implications for financial institutions on when demand for auto loans and the associated risk arise.


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1261
Author(s):  
Christopher Gradwohl ◽  
Vesna Dimitrievska ◽  
Federico Pittino ◽  
Wolfgang Muehleisen ◽  
András Montvay ◽  
...  

Photovoltaic (PV) technology allows large-scale investments in a renewable power-generating system at a competitive levelized cost of electricity (LCOE) and with a low environmental impact. Large-scale PV installations operate in a highly competitive market environment where even small performance losses have a high impact on profit margins. Therefore, operation at maximum performance is the key for long-term profitability. This can be achieved by advanced performance monitoring and instant or gradual failure detection methodologies. We present in this paper a combined approach on model-based fault detection by means of physical and statistical models and failure diagnosis based on physics of failure. Both approaches contribute to optimized PV plant operation and maintenance based on typically available supervisory control and data acquisition (SCADA) data. The failure detection and diagnosis capabilities were demonstrated in a case study based on six years of SCADA data from a PV plant in Slovenia. In this case study, underperforming values of the inverters of the PV plant were reliably detected and possible root causes were identified. Our work has led us to conclude that the combined approach can contribute to an efficient and long-term operation of photovoltaic power plants with a maximum energy yield and can be applied to the monitoring of photovoltaic plants.


2021 ◽  
Vol 13 (6) ◽  
pp. 3364
Author(s):  
Amr Zeedan ◽  
Abdulaziz Barakeh ◽  
Khaled Al-Fakhroo ◽  
Farid Touati ◽  
Antonio S. P. Gonzales

Soiling losses of photovoltaic (PV) panels due to dust lead to a significant decrease in solar energy yield and result in economic losses; this hence poses critical challenges to the viability of PV in smart grid systems. In this paper, these losses are quantified under Qatar’s harsh environment. This quantification is based on experimental data from long-term measurements of various climatic parameters and the output power of PV panels located in Qatar University’s Solar facility in Doha, Qatar, using a customized measurement and monitoring setup. A data processing algorithm was deliberately developed and applied, which aimed to correlate output power to ambient dust density in the vicinity of PV panels. It was found that, without cleaning, soiling reduced the output power by 43% after six months of exposure to an average ambient dust density of 0.7 mg/m3. The power and economic loss that would result from this power reduction for Qatar’s ongoing solar PV projects has also been estimated. For example, for the Al-Kharasaah project power plant, similar soiling loss would result in about a 10% power decrease after six months for typical ranges of dust density in Qatar’s environment; this, in turn, would result in an 11,000 QAR/h financial loss. This would pose a pressing need to mitigate soiling effects in PV power plants.


2020 ◽  
Vol 48 (7) ◽  
pp. 030006052094211
Author(s):  
Wei Zhang ◽  
Feng Xue ◽  
Quandong Bu ◽  
Xuemei Liu

Hypocalcemia is a rare, but reversible, cause of dilated cardiomyopathy. Although cardiomyopathy may cause severe heart failure, calcium supplementation can reverse heart failure. We report here a patient with uremia and secondary hyperparathyroidism, who was complicated by persistent hypocalcemia and refractory heart failure. The cardiac failure was refractory to treatment with digitalis and diuretics, but dramatically responded to calcium therapy and restoration of normocalcemia. As a result, the patient was eventually diagnosed with hypocalcemic cardiomyopathy. To the best of our knowledge, this is the first case of this disease to be reported in a patient with uremia. Findings from our case may help clinicians to better understand hypocalcemic cardiomyopathy. Our case might also provide new insight into long-term cardiac complications and prognoses of patients undergoing parathyroidectomy due to secondary hyperparathyroidism.


1998 ◽  
Vol 11 (1) ◽  
pp. 379-379
Author(s):  
P.L. Cottrell ◽  
L. Skuljan ◽  
P.M. Kilmartin ◽  
C. Gilmore ◽  
W.A. Lawson

For more than a decade we have been able to acquire and analyse a significant amount of photometric data of the highly variable R Coronae Borealis (RCB) stars. This has made been possible by a photometric service observing programme instigated at the Observatory. These photometric data have been combined with less extensive spectroscopic coverage, particularly of the decline phase of these stars. These have been supplemented by observations obtained at Mount Stromlo and Siding Spring Observatories for a radial velocity study. Significantly more spectroscopic observations are now being acquired with the development of a new medium resolution spectrograph at Mount John University Observatory. In this poster we will present recent photometric and spectroscopic results for a number of the RCB stars in our sample. This observational and analysis work can be used to provide further insight into the nature of these stars, their likely progeny and progenitors and the processes that are involved in the formation and evolution of the obscuring dust clouds which cause the decline phase.


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