Nawaf Ali Alhaifi

Accurate unit transportation cost estimates are important for pricing, budgeting, and fleet planning, but conclusions based on a single representative vehicle may be misleading when operating conditions vary across fleets, routes, operators, and years. This study develops a multi-source Kuwait framework that combines deterministic vehicle-level sensitivity analysis with independent truck, route, operator, and fleet evidence. One-at-a-time perturbations, sensitivity-index ranking, local elasticity, factorial stress tests, and fuel-price scenarios are applied to published freight-truck and passenger-bus cost cases. The principal contribution is a cross-resolution framework that links equation-level cost sensitivity with independently observed operational heterogeneity while preserving the analytical resolution of each dataset and avoiding inappropriate pooling of incompatible sources. In the vehicle-level sensitivity core, annual kilometers is the leading truck parameter (SI = 16.54%), followed by maintenance cost (6.18%) and driver/worker salary (5.67%), whereas bus occupancy rate (20.79%) and annual kilometers (16.45%) are dominant. As independent contextual evidence, historical Kuwait truck observations show mean transported loads of 2.0–5.0 t/truck, while KPTC route offered-capacity utilization ranges from 13.3% to 99.7%. The results show that productive activity and utilization strongly influence unit transportation cost, but their effects are context dependent. The framework therefore improves the practical interpretation and transferability of deterministic vehicle-level sensitivity results without overstating cross-source validation.

This study presents a comprehensive techno-economic and environmental evaluation of ten standalone solar-powered mobile charging station configurations for mini electric vehicles (MEVs) in Kuwait, simulated using HOMER Pro (v3.18.4). The configurations span DC–AC and pure DC-bus architectures, fixed and tracking photovoltaic (PV) systems, hybrid designs incorporating diesel generator backup, and fully renewable zero-emission systems. All configurations were evaluated under identical load demand (6460 kWh/year), solar resource, and economic assumptions derived from Kuwait’s desert climate at Al-Wafra farms (28°33′52.7″ N, 48°03′45.8″ E, annual average GHI = 5.49 kWh·m⁻²·day⁻¹). Performance was assessed using Net Present Cost (NPC), Levelised Cost of Energy (LCOE), annual PV energy production, CO₂ emissions, Energy Production Density (EPD), Renewable Fraction (RF), and the PV Energy Production-to-Load Ratio (PV-EPTLR). The results demonstrate that two-axis tracking on a DC-bank architecture without a generator (System 8) achieves the highest annual PV output of 13,635 kWh/year, representing a 36% increase over a fixed-tilt DC-bank system while eliminating 100% of operational CO₂ emissions. Among the hybrid configurations, vertical single-axis tracking on a DC-bank architecture with generator backup (System 6) yields the lowest lifecycle cost (NPC = USD 6271.8; LCOE = 0.0751 USD/kWh), representing a 57% reduction relative to the fixed-tilt DC–AC baseline. EPD analysis confirms that tracking-based systems improve structural energy efficiency by up to 36%, making them particularly suitable for mobile and weight-constrained deployments. The findings provide actionable guidance for deploying sustainable off-grid MEV charging infrastructure in regions with limited grid access, offering a scalable pathway toward zero-emission rural transportation in solar-rich arid environments. The study further provides a systematic comparison between DC–AC and pure DC-bank charging architectures under identical operating conditions.