A Sizing Method for PV–Battery–Generator Systems for Off-Grid Applications Based on the LCOE

Electricity supply in nonelectrified areas can be covered by distributed renewable energy systems. The main disadvantage of these systems is the intermittent and often unpredictable nature of renewable energy sources. Moreover, the temporal distribution of renewable energy may not match that of energy demand. Systems that combine photovoltaic modules with electrical energy storage (EES) can eliminate the above disadvantages. However, the adoption of such solutions is often financially prohibitive. Therefore, all parameters that lead to a functionally reliable and self-sufficient power generation system should be carefully considered during the design phase of such systems. This study proposes a sizing method for off-grid electrification systems consisting of photovoltaics (PV), batteries, and a diesel generator set. The method is based on the optimal number of PV panels and battery energy capacity whilst minimizing the levelized cost of electricity (LCOE) for a period of 25 years. Validations against a synthesized load profile produced grid-independent systems backed by different accumulator technologies, with LCOEs ranging from 0.34 EUR/kWh to 0.46 EUR/kWh. The applied algorithm emphasizes a parameter of useful energy as a key output parameter for which the solar harvest is maximized in parallel with the minimization of the LCOE

Vibration-based Energy Harvesting Systems Characterization Using Automated Electronic Equipment

A measurement bench has been developed to fully automate the procedure for the characterization of a vibration-based energy scavenging system. The measurement system is capable of monitoring all important characteristics of a vibration harvesting system (input and output voltage, current, and other parameters, frequency and acceleration values, etc.). It is composed of a PC, typical digital measuring instruments (oscilloscope, waveform generator, etc.), certain sensors and actuators, along with a microcontroller based automation module. The automation of the procedure and the manipulation of the acquired data are performed by LabVIEW software. Typical measurements of a system consisting of a vibrating source, a vibration transducer and an active rectifier are presented

A Techno-Economic Analysis of a PV-Battery System in Greece

A techno-economic assessment has been carried out to evaluate the economic feasibility of energy self-consumption from a combination of photovoltaics and lead-acid batteries (PV-BAT). The Total annual economic cost (TAEC) and the cost per unit of energy were first calculated, from PV-BAT data collected over a 12 month period and then from energy system model data for the same period. A comparison of the actual renewable energy yield to optimal model output revealed that energy was restrained partially due to limited storage resources. The cost per kilowatt-hour for the two examined scenarios ranged from 0.55 to 0.62 €/kWh and from 0.42 to 0.46 €/kWh, respectively, showing room for further cost reductions. Despite currently lower energy purchasing costs from electricity providers, these findings constitute a significant price indication of the kilowatt-hour produced by PV-BAT, showing the need for further investigation into how battery sizing can be optimized and battery cost can be reduced

Design considerations for a DC-DC boost converter in standard CMOS technology

Summarization: In this paper, the challenges of designing a boost converter in standard CMOS technology are discussed. Based on theoretical calculations, which take into consideration the characteristics of the technology used, efficient solutions are proposed to overcome the current-stress limitations as well as the power dissipation issues. Following these guidelines, a test DC-DC converter, designed and fabricated in a standard 0.18um CMOS process is presented, along with experimental results.Παρουσιάστηκε στο: 2021 10th International Conference on Modern Circuits and Systems Technologie

Current trends in the management of uremic restless legs syndrome: A systematic review on aspects related to quality of life, cardiovascular mortality and survival

Restless legs syndrome (RLS) affects almost one out of three end-stage renal disease patients. This review assesses the current treatment options for uremic RLS and the potential benefits of those treatments on quality of life parameters, cardiovascular mortality and Survival. A systematic review was conducted searching PubMed and Scopus by using the Cochrane and PRISMA guidelines. Fourteen studies met the inclusion criteria in which the international RLS study group criteria were used as the primary diagnostic tool. Both pharmacological and non-pharmacological approaches were found to reduce the severity of uremic RLS symptoms. Only four studies reported changes on aspects related to quality of life while those changes were also associated with health benefits that resulted in reduced cardiovascular risk. The severity of uremic RLS symptoms can be ameliorated by using dopamine agonists and gabapentin, intravenous iron, exercise or supplementation with vitamins C and E, although some of those treatment benefits may be transient. There is a lack of strong evidence regarding the effects of the pharmacological approaches on quality of life and cardiovascular survival and mortality. In contrast exercise has been proven beneficial in both reducing the RLS symptoms' severity score and improving the quality of life. (C) 2014 Elsevier Ltd. All rights reserved