Mangottiri Vasudevan

The success of wind energy projects depends on reliable site selection and cost-effective operation. Existing studies largely focus on either resource potential or standalone economic feasibility, while a unified wind power rating framework for site prioritization across India remains lacking. This study proposes a multi-criteria wind power assessment framework and investigates the spatial and scale-dependent variability of wind speed (WS) and wind power density (WPD) over six major regions of India. Hourly WS data were at diurnal, monthly and annual scales to capture atmospheric and seasonal influences. The results reveal significant temporal variabilities in WS and WPD, especially over the southern and western coastal and high-altitude regions during the monsoon months (June–August). The spatial analysis revealed a non-linearly increasing trend for WS with altitude, contrary to the simplifying assumptions. Regions such as the Southern Peninsular States (SPSs) and western middle states (WMSs) show high suitability for large-scale deployment, whereas the Northeastern States (NESs) and parts of northern border states (NBS) exhibit lower potential. The site suitability is further evaluated using wind variability indices such as the wind variability index (WVI) and Windy Site Identifier (WSI), along with the plant capacity factor (PCF), cost of energy (COE), and greenhouse gas (GHG) emissions, enabling a comprehensive and decision-oriented framework for wind energy planning.

Understanding the mass transfer and transport of dissolved chemicals in layered heterogeneous porous media invokes unique challenges in our comprehension of the subsurface environment. In the present study, we explore the transport mechanism of dissolved nitrate as a critical pollutant through a three-layered porous media. Particularly, the consequences of bulk mass transfer effects at the layer interfaces were portrayed for various combinations of medium sand (M), fine sand (F), natural soil (N), and silt (S) with a numerical model using an implict finite difference scheme. Based on the extent of observed mass transfer constraints exhibited by the layer interfaces, the critical combinations simulated for various scenarios include F-M-S, M-S-N, and N-F-M. The numerical predictions are made for fixed time intervals of 10, 20, and 30 minutes, with retardation factors ranging from 1.0 to 1.4 and velocities from 0.1 to 0.3 cm per minute, respectively. For the N-S-N scenario, the results showed that the third layer would have the most nitrate buildup (1.25 mg/L). Further investigation on the mass transfer effects revealed that the solute movement is significantly arrested at the end of the first layer due to poor dispersion, which further influenced the advancement in the consecutive layers for other combinations of soils as well. It is also observed that the effect of nonreactive adsorption is least significant in the third layer for the M-S-N scenario, thus contributing to an enhanced aqueous concentration at the bottom interface. The present model thus offers an effective assessment strategy for the vulnerability of groundwater to leaching contaminations in layered porous domains.