An assessment study of evaporation rate models on a water basin with floating photovoltaic plants

Under the general topic of the impact of floating PV systems (FPVs) on water basins, the present study aims to model and analyze the effect of FPVs on the evaporation rate of water surfaces. The estimation of the evaporation of the water surface of a basin is usually calculated using mathematical evaporation models that require knowledge of some parameters (i.e. solar radiation, humidity, air temperature, water temperature, wind velocity). Thus, in the first section of this study some evaporative models (EVM) for free water basin have been examined to evaluate which are the environmental variables used. On the basis of this analysis, new numerical models for the calculation of the daily evaporation rate have been developed using the DoE method (3 models) and the linear regression method (2 models). The results of the developed models have been compared with the experimental measurements carried out by an evaporimeter, such comparison has highlighted the robustness of the proposed numerical models. Moreover, for estimating the evaporation rate in water basins partially covered by FPVs further three numerical methods are proposed. Finally, the evaporation rates, arising by the installation of different typology of FPVs on water basins, have been evaluated as function of the energy balance on the water surface. It is possible to highlight that the amount of evaporated water depends not only on the percentage of surface covered but also on the characteristics of floating systems. Covering only 30% of the surface of a basin, it is possible to obtain up to 49% reduction in evaporation

Economic comparison of floating photovoltaic systems with tracking systems and active cooling in a Mediterranean water basin

Floating Photovoltaic (FPV) modules are installed on water surface to reduce land use. This original solution, potentially deployable on hydropower and aquaculture basins as well, can benefit of enhanced cooling due to the proximity to water. Thanks to this natural effect, FPV modules can work at higher operating efficiencies than ground-based (GPV) modules. However, because of the relatively young age, FPV still requires higher installation costs than GPV. This study investigates the economic competitiveness of GPV and FPV in terms of energy performance and total costs. Different PV system solutions are economically evaluated on the basis of three key figures, namely the capital costs (CAPEX), the operation and maintenance costs (OPEX) and the power generation costs (LCOE). An economic ranking is created based on the comparative analysis of these three key figures. The crucial point in the proposed economic model is that the revenues resulting from the reduced evaporations are considered as well. Every year, indeed, a significant volume of water can be preserved thanks to the shading effect of FPV modules. This water can be used for various purposes, increasing the overall revenues of the FPV system. In addition, the present LCOE calculations also take into account the performance enhancements that could be achieved through the installation of active cooling systems. In light of the expected economy of scale, a sensitivity analysis of the LCOE is carried out to account potential reductions in the capital cost of FPVs. This is done by analyzing the energy and economic performance of various FPV designs on a water basin in Southern Italy. The results demonstrate that, reducing the CAPEX of the FPV by 30 %, a nearly 20 % reduction in LCOE can be obtained compared to the reference GPV system

Employment and working conditions of nurses: where and how health inequalities have increased during the COVID-19 pandemic?

Background: Nurses and midwives play a critical role in the provision of care and the optimization of health services resources worldwide, which is particularly relevant during the current COVID-19 pandemic. However, they can only provide quality services if their work environment provides adequate conditions to support them. Today the employment and working conditions of many nurses worldwide are precarious, and the current pandemic has prompted more visibility to the vulnerability to health-damaging factors of nurses' globally. This desk review explores how employment relations, and employment and working conditions may be negatively affecting the health of nurses in countries such as Brazil, Croatia, India, Ireland, Italy, México, Nepal, Spain, and the United Kingdom. Main body: Nurses' health is influenced by the broader social, economic, and political system and the redistribution of power relations that creates new policies regarding the labour market and the welfare state. The vulnerability faced by nurses is heightened by gender inequalities, in addition to social class, ethnicity/race (and caste), age and migrant status, that are inequality axes that explain why nurses' workers, and often their families, are exposed to multiple risks and/or poorer health. Before the COVID-19 pandemic, informalization of nurses' employment and working conditions were unfair and harmed their health. During COVID-19 pandemic, there is evidence that the employment and working conditions of nurses are associated to poor physical and mental health. Conclusion: The protection of nurses' health is paramount. International and national enforceable standards are needed, along with economic and health policies designed to substantially improve employment and working conditions for nurses and work-life balance. More knowledge is needed to understand the pathways and mechanisms on how precariousness might affect nurses' health and monitor the progress towards nurses' health equity

Recent technical advancements, economics and environmental impacts of floating photovoltaic solar energy conversion systems

International audienc