Energy performance of concentrator and flat plate photovoltaics in the mediterranean area
A comparative analysis of the energy production of a High Concentrator Photovoltaic (CPV) and a flat plate amorphous photovoltaic (PV) plants, installed in the same place in the southern Italy, is presented. This analysis aims at providing reliable production values of CPV based on a long term monitoring with reference to this specific geographic zone. The daily normalized power production in different weather conditions is presented and the correlation between energy production and daily solar irradiance is discussed. Further, a statistical analysis on the normalized energy production is developed for both plants, referring to the measured historical data. Finally, economic aspects and the evaluation of levelized cost of energy for CPV based on in-field data are reported. On the basis of these considerations, the feasibility of CPV systems in southern Europe are discussed.
Levelized Cost of Electricity: PV and CPV in Comparison to Other Technologies
This paper presents the findings of the Fraunhofer ISE study on the levelized cost of electricity (LCOE) of renewable energy technologies with a focus on PV (Fraunhofer ISE, 2013). It predicts future cost and market developments through 2030 based on technology-specific learning curves and market scenarios. Photovoltaics (PV) are assessed in Germany. Moreover, the solar technologies PV and concentrating photovoltaics (CPV) are analyzed in regions with higher solar irradiation. They are compared to other renewable energy technologies such as (onshore and offshore) wind power, concentrating solar power (CSP) and biogas on the basis of common market financing costs. The current and future LCOE for new conventional power plants (brown coal, hard coal, combined cycle gas turbine (CCGT), oil-fired power plants) are calculated as a reference.
Studies on root enamel (2). Enamel pearls. A review of their morphology, localization, nomenclature, occurrence, classification, histogenesis and incidence.
Enamel pearls are one of a number of different enamel structures that can be found on the roots of deciduous and permanent teeth. They have a distinct predilection for the furcation areas of molar teeth, particularly the maxillary third and second molars. They can consist primarily of enamel, but in most instances, a core of dentin is contained within them. On rare occasions, even pulpal tissues can be found. Enamel pearls usually occur singularly, but up to 4 enamel pearls have been observed on the same tooth. Depending on the study, enamel pearls on permanent molar teeth have an incidence rate of between 1.1%-9.7% with distinct differences among racial and national groups. The incidence of enamel pearls increases greatly in histological studies, suggesting that they are often obscured by a covering of cementum.