Techno-economic analysis of on-site energy storage units to mitigate wind energy curtailment : a case study in Scotland

Wind energy plays a major role in decarbonisation of the electricity sector and supports achieving net-zero greenhouse gas emissions. Over the last decade, the wind energy deployments have grown steadily, accounting for more than one fourth of the annual electricity generation in countries like the United Kingdom, Denmark, and Germany. However, as the share of wind energy increases, system operators face challenges in managing excessive wind generation due to its nondispatchable nature. Currently, the most common practice is wind energy curtailment in which wind farm operators receive constraint payments to reduce their renewable energy production. This practice not only leads to wastage of large volumes of renewable energy, but also the associated financial cost is reflected to rate payers in the form of increased electricity bills. On-site energy storage technologies come to the forefront as a technology option to minimise wind energy curtailment and to harness wind energy in a more efficient way. To that end, this paper, first, systematically evaluates different energy storage options for wind energy farms. Second, a depth analysis of curtailment and constraint payments of major wind energy farms in Scotland are presented. Third, using actual wind and market datasets, a techno-economic analysis is conducted to examine the relationship between on-site energy storage size and the amount of curtailment. The results show that, similar to recent deployments, lithium-ion technology is best suited for on-site storage. As case studies, Whitelee and Gordon bush wind farms in Scotland are chosen. The most suitable storage capacities for 20 years payback period is calculated as follows: (i) the storage size for the Gordonbush wind farm is 100 MWh and almost 19% of total curtailment can be avoided and (ii) the storage size for the Whitlee farm is 125 MWh which can reduce the curtailment by 20.2%. The outcomes of this study will shed light into analysing curtailment reduction potential of future wind farms including floating islands, seaports, and other floating systems

The effect of serum and follicular fluid anti-Mullerian hormone level on the number of oocytes retrieved and rate of fertilization and clinical pregnancy

WOS: 000408979800002PubMed: 28058394OBJECTIVE: The objective of this study was to evaluate the relationship between oocyte yield, fertilization, and clinical pregnancy (CP), and anti-Mullerian hormone (AMH) level in serum and follicular fluid during in vitro fertilization treatment. METHODS: Forty-four infertile women who underwent IVF treatment using multiagonist protocol were included in this study. Baseline level of AMH in serum and follicular fluid was measured on third day of menstrual cycle. AMH level in serum and follicular fluid was then measured again on day of oocyte pick-up. Pearson correlation and binary regression tests were used for statistical analysis. For Type 1 error, p= 5% was selected as cut-off value for statistical significance. RESULTS: Serum AMH level was positively correlated with total number of oocytes retrieved and rate of fertilization and CP (r= 0.397, p= 0.008; r= 0.401, p= 0.007; and r= 0.382, p= 0.011, respectively). There was significantly negative correlation between serum level of follicle-stimulating hormone (FSH) and fertilization rate (r=-0.320; p= 0.034), as well as serum FSH level and CP rate (r=-0.308; p= 0.042). There were no significant correlations between AMH level in follicular fluid and IVF treatment outcomes. CONCLUSION: Serum AMH levels may be more reliable for prediction of total number of oocytes retrieved and rate of fertilization and CP than AMH levels in follicular fluid

Diagnosis: Melanoderma After Hematopoietic Stem Cell Transplantation

PubMedScopu

Elevated levels of short-term blood pressure variability: A marker for ascending aortic dilatation in hypertensive patients

Background: Ascending aortic aneurysms are one of the primary causes of mortality. However, not much is known about the etiologies of aortic aneurysm. Recently, in hypertensive (HT) patients, blood pressure variability (BPV) has been recommended as a remarkable risk factor for adverse cardiovascular outcomes. This study aimed to explore the association between short-term BPV and ascending aortic dilatation (AAD). Methods: In this study, a total of 53 HT patients with AAD (aortic size index [ASI] ≥21 mm/m2) and 126 HT patients with a normal ascending aortic diameter (ASI 12.95 had a sensitivity of 61% and a specificity of 59% (area under the curve, 0.659; 95% CI, 0.562–0.756; P= .01); moreover, daytime SD of SBP > 16.4 had sensitivity of 62% and specificity of 61% (AUC, 0.687; 95% CI, 0.591–0.782; P< .001). :Conclusion Increased short-term BPV is independently associated with AAD and may be recommended as a remarkable factor risk for AAD in HT patients

THE IMPORTANCE OF GLOMERULAR C3 ACCUMULATION IN ELDERLY PATIENTS WITH PRIMARY MEMBRANOUS NEPHROPATHY

Objective: The purpose of this study was to investigate the impact of glomerular C3 accumulation density on clinical, histopathological parameters and outcomes in elderly (>60 years) individuals with primary membranous nephropathy (PMN)