7 research outputs found
Performance of grid-tied PV facilities based on real data in Spain: Central inverter versus string system
Two complete years of operation of two grid-tied PV facilities is presented. Energetic and economic performance of both installations has been compared. Located in the same place, the installation of these facilities followed the same construction criteria – PV panels, panel support system and wiring – and the facilities are exposed to the same atmospheric temperature and solar radiation. They differ with regard to their inverter topology used: one facility uses a central inverter and the other a string inverter configuration. The performance of the facilities has been determined using a procedure based on a small number of easily obtained parameters and the knowledge of the analyzed system and its operation mode. Electrical losses have been calculated for both systems and a complete comparison between them has been carried out. The results have shown better performance for distributed system in economic and energetic terms.Spanish Government (Grant ENE2011-27511) and the Department of Culture and Education of the Regional Government of Castilla y León, Spain (Grant BU358A12-2)
Performance analysis of PV plants: Optimization for improving profitability
A study is conducted of real PV production from two 100 kWp grid-connected installations located in the same area, both of which experience the same fluctuations in temperature and radiation. Data sets on production were collected over an entire year and both installations were compared under various levels of radiation. The installations were assembled with mono-Si panels, mounted on the same support system, and the power supply was equal for the inverter and the measurement system; the same parameters were also employed for the wiring, and electrical losses were calculated in both cases. The results, in economic terms, highlight the importance of properly selecting the system components and the design parameters for maximum profitabilit
A new diffuse luminous efficacy model for daylight availability in Burgos, Spain
The determination of optimal illumination conditions in buildings is of great interest both for reducing energy consumption and for exploiting solar resources with greater efficiency and sustainability. The most commonplace method of estimating daylight is the luminous efficacy approach, using the more widely measured solar irradiance. In this present study, a new model of diffuse luminous efficacy over a horizontal surface is proposed. A comparative study of twenty-two classic models is presented, to obtain diffuse illuminance, using both, the original mathematical models and the adapted models with local coefficients, in order to determine the most suitable models for Burgos, a city located in north-western Spain. With this purpose in mind, twelve models are selected for all sky conditions, five models for modelling clear sky, two for partly cloudy sky, and three for overcast sky. These twenty-two models are then compared with the new model both for all sky conditions and for particular sky conditions (clear, partly cloudy, and overcast). The behaviour of the new model showed greater accuracy than most of the classic models under analysis. Hence, the advantage of the diffuse luminous efficacy model that can be applied both to all sky and to particular sky conditions.Spanish Government (Ministerio de EconomĂa y Competitividad) (ENE2014-54601-R). David González Peña would also like to thank the Junta de Castilla-LeĂłn for economic support (PIRTU Program, ORDEN EDU/310/2015)
Performance of grid-tied PV facilities: a case study based on real data
A new procedure is presented to analyse the performance of grid-tied PV facilities. It needs limited amounts of data that are easily sourced and is based on knowledge of the analysed system and its mode of operation. The procedure is applied, in a case study, to compare real PV production at two 100 kWp grid-connected PV installations. Located in the same geographical region, the installation of these two facilities followed the same construction criteria – PV panels, panel support system and wiring – and the facilities were exposed to the same atmospheric temperature and solar radiation. They differ with regard to their inverter technology: one facility uses an inverter with an integrated transformer system and the other uses a transformerless inverter. The results show that the transformerless inverter system performed better than the isolated system by a factor of 1.2%, which, in economic terms, represents more than 2000 €/yearSpanish Government (Grant ENE2011-27511) and the Department of Culture and Education of the Regional Government of Castilla y León, Spain (Grant BU358A12-2)
Diet quality index as a predictor of treatment efficacy in overweight and obese adolescents: The EVASYON study
Background & aim: A diet quality index (DQI) is a tool that provides an overall score of an individual''s dietary intake when assessing compliance with food-based dietary guidelines. A number of DQIs have emerged, albeit their associations with health-related outcomes are debated. The aim of the present study was to assess whether adherence to dietary intervention, and the overall quality of the diet, can predict body composition changes. Methods: To this purpose, overweight/obese adolescents (n = 117, aged: 13–16 years; 51 males, 66 females) were recruited into a multi-component (diet, physical activity and psychological support) family-based group treatment programme. We measured the adolescents’ compliance and body composition at baseline and after 2 months (intensive phase) and 13 months (extensive phase) of follow-up. Also, at baseline, after 6 months, and at the end of follow-up we calculated the DQI. Results: Global compliance with the dietary intervention was 37.4% during the intensive phase, and 14.3% during the extensive phase. Physical activity compliance was 94.1% at 2-months and 34.7% at 13months and psychological support compliance were growing over the intervention period (10.3% intensive phase and 45.3% during extensive phase). Adolescents complying with the meal frequency criteria at the end of the extensive phase had greater reductions in FMI z-scores than those did not complying (Cohen''s d = 0.53). A statistically significant association was observed with the diet quality index. DQI-A variation explained 98.1% of BMI z-score changes and 95.1% of FMI changes. Conclusions: We conclude that assessment of changes in diet quality could be a useful tool in predicting body composition changes in obese adolescents involved in a diet and physical activity intervention programme backed-up by psychological and family support
Implementation of PV plants in Spain: A case study
The implementation process of a photovoltaic system and its connection to the national grid in Spain is examined from an economic, an administrative and a legal standpoint. In the first place, this case study describes the solar farm, and it goes on to examine the economic aspects of electricity production, its associated costs, and relevant grants and financial subsidies. Finally, problems related to the administration of the project and the issuing of permits by local and regional authorities are discussed.PV grid-connected systems PV production PV support Administrative process
Characteristics and outcomes of adult patients in the PETHEMA registry with relapsed or refractory FLT3-ITD mutation-positive acute myeloid leukemia
Simple Summary Most adult patients with acute myeloid leukemia (AML) relapse after achieving complete remission with chemotherapy; however, there is no standard second-line (salvage) treatment. We retrospectively investigated 404 patients aged >= 18 years with relapsed/refractory (R/R) AML with an FMS-like tyrosine kinase 3 (FLT3) mutation, treated at a PETHEMA (NCT02607059) site between 1998 and 2018. Patients received salvage treatment with intensive therapy (n = 261), non-intensive therapy (n = 63) or supportive care (n = 80). Complete remission was achieved by 48% of patients who received intensive therapy vs. 19% with non-intensive therapy. Intensive/non-intensive therapy prolonged overall survival significantly compared with supportive therapy. Of evaluable patients, 22% received an allogeneic stem-cell transplant after complete remission. The majority of patients with FLT3-mutated R/R AML received intensive salvage therapy, with the best outcomes being obtained when intensive salvage treatment was combined with stem-cell transplant. This retrospective study investigated outcomes of 404 patients with relapsed/refractory (R/R) FMS-like tyrosine kinase 3 (FLT3)-internal tandem duplication (ITD) acute myeloid leukemia (AML) enrolled in the PETHEMA registry, pre-approval of tyrosine kinase inhibitors. Most patients (63%) had received first-line intensive therapy with 3 + 7. Subsequently, patients received salvage with intensive therapy (n = 261), non-intensive therapy (n = 63) or supportive care only (n = 80). Active salvage therapy (i.e., intensive or non-intensive therapy) resulted in a complete remission (CR) or CR without hematological recovery (CRi) rate of 42%. More patients achieved a CR/CRi with intensive (48%) compared with non-intensive (19%) salvage therapy (p < 0.001). In the overall population, median overall survival (OS) was 5.5 months; 1- and 5-year OS rates were 25% and 7%. OS was significantly (p < 0.001) prolonged with intensive or non-intensive salvage therapy compared with supportive therapy, and in those achieving CR/CRi versus no responders. Of 280 evaluable patients, 61 (22%) had an allogeneic stem-cell transplant after they had achieved CR/CRi. In conclusion, in this large cohort study, salvage treatment approaches for patients with FLT3-ITD mutated R/R AML were heterogeneous. Median OS was poor with both non-intensive and intensive salvage therapy, with best long-term outcomes obtained in patients who achieved CR/CRi and subsequently underwent allogeneic stem-cell transplant