Road Transport Research Articles

Investigating the Need for Urban Air Mobility in Tehran City

The increase in urbanization has led to the creation of dense population in urban areas, along with economic development and the increase in vehicles, which has led to an increase in demand and consequently an increase in many challenges regarding mobility and infrastructure. Solving these challenges or reducing the effects of these challenges can have significant effects on people's daily lives. Various solutions have always been proposed to solve these challenges, some of which have been successful and some of which have not. In the city of Tehran, too, challenges have arisen due to the rapid growth of urbanization, population, and vehicles, and solutions have been proposed to solve these challenges or improve the conditions, but due to the current conditions in Tehran, these solutions have not been able to appear as successful as they should be. In this paper, by examining the conditions of Tehran in terms of noise pollution, energy and fuel consumption, air pollution, traffic conditions, public and road transportation, it is proved that Tehran needs a new mode of transportation. According to today's needs of Tehran, this new mode of transportation can be an urban air mobility (UAM) that can be used in areas such as passenger and goods transportation. The presence of this mode of transportation in the transportation system of Tehran, in addition to improving the level of transportation of this city, helps to improve and even solve the challenges of today's transportation in Tehran, such as the high noise pollution of this city.

Development and validation of a new asphalt mixture to reduce tyre-road contact noise in interurban areas

Road transport is one of the most important sources of noise emissions having a serious impact on human health. Thus, the objective of this study is to develop an innovative asphalt mixture that decreases noise from tyre and pavement interaction on highways with average speeds of about 80 km/h. To achieve this, a series of mechanical and functional tests were conducted both in the laboratory and at the Gustave Eiffel University Accelerated Pavement Testing (APT) facility. The new experimental mixture achieves a balance between high void content and low macro-texture (wavelengths of 5–50 mm), which improves noise reduction while maintaining good mechanical performance. This is achieved thanks to its two-layer structure, with a top layer of reduced maximum aggregate size (4 mm) and a thickness suitable for optimum sound absorption. Various mechanical tests, including the particle loss test and the water sensitivity test, along with functional evaluations focusing on texture, flow resistivity and sound absorption properties, were performed. Measurements on the APT were taken at three different stages of the pavement service lifetime during the testing phase. The outcome was the production of an asphalt mixture that reduced noise up to 6.8 dB in comparison to an asphalt concrete road.

Impact of Driving Timing and Road Types on the Operating Regions of Electric Two-wheeler Powertrain Components under Indian Road Conditions

Among the different classes of electric vehicles (EVs), electric two-wheelers (E2Ws) are securing more enticement towards the commutator for regular usage due to their higher suitability in the heterogeneous traffic conditions of India. However, the driving range of the E2Ws is the major concern in increasing its penetration rate in road transportation. To eradicate the range anxiety of commutators by redesigning the current E2W powertrain configuration, this study strives to insights into the operational limits of powertrain elements such as the battery and motor in E2W under multiple operational circumstances such as driving style, pavement, and ambient conditions. Regarding this, the E2W with data acquisition system (DAC) connected with an onboard diagnosis (OBD) port is utilized to acquire the data related to powertrain components and vehicles for four driving trips (trips 1–4) under three major road segments (Rural, expressway, and urban) of India. The operating and computed performance metrics, comprising battery voltage and current, state-of-charge (SOC), energy consumption, motor current, speed, efficiency, and so on, are then compared throughout driving trips and road segments. The mean velocity of E2W for trips 1 to 4 is 31.91, 33.68, 39.03, and 35.58 km/h, respectively. The results disclosed that total energy consumption and energy consumption per km. are higher during trip 3 due to higher average vehicle speed. Also, it has a higher depth-of-discharge (DOD) of 83.91 % than other driving trips. Further, a higher rate of SOC drop, energy consumption and battery temperature rise are found at highway road segments.

Developing design-basis PSD loads for spent nuclear fuel transport: Insights from cask test results

From 2020 to 2021, multimodal transportation tests were conducted in South Korea. Surrogate fuel assemblies were loaded into a full-sized transportation cask for road and sea transportation tests at Doosan Enerbility and along a South Korean seashore. The study focused on the effects of normal transport conditions on spent nuclear fuel (SNF) and its structural integrity by analyzing the data obtained. Additionally, the need to analytically assess the integrity of spent fuel under these conditions through design-basis loads has emerged. This study focuses on generating the input load. The study also addressed the practical considerations for applicants regarding the format of these design loads. For all tested conditions, design-basis power spectral density (PSD) loads were identified, covering PSDs at the basket across various transportation conditions. A comprehensive diagram capturing the PSDs at the basket, which then transmitted the load to the fuel assembly for each transport scenario, was calculated as the design load. The transportation test load data served as inputs for the shake table test, which aimed to closely evaluate the behavior of the fuel assemblies. The appropriateness and conservativeness of the derived design-basis PSD were validated through a shake table tests.

DECARBONIZING FREIGHT TRANSPORTATION IN BRAZIL: METHODOLOGIES, RESULTS AND PRACTICAL IMPLICATIONS

Objective: The objective of this technological article is to present a practical tool for calculating CO2 emissions based on fuel consumption applied in a small road freight transport company. Theoretical Framework: There are 4 methods available in the literature for calculating CO2 emissions produced during cargo transport, which stand out for their applicability: (1) GHG Procol; (2) MNT; (3) DEFRA; and (4) GLEC. The authors (Leonardi & Baumgartner, 2004; Lewis et al., 2016) have methodologies for calculating emissions from freight transport, which currently present significant variability in the approaches and databases recommended. The main methodologies in this area are based on two main foundations: (1) fuel-based methodologies; (2) activity-based methodologies. Method: The calculation methodology used is based on fuel consumption (bottom-up), which considered the characteristics of the target fleet, the number of vehicles and their technological phase, the actual intensity of fleet use in operation, and real fuel consumption. Results and Discussion: From this initial information, it was possible to obtain the volume of CO2 emissions specific to the fleet, considering vehicles using regular diesel and biodiesel (S10). The results indicated a fleet CO2 emission of 1,643 tons per year with the use of biodiesel (S10), representing a 10.5% reduction compared to the total CO2 emission from regular diesel. Research Implications: The practical and theoretical implications of this research are discussed, providing insights into how the results can be applied or influence practices in the field of [insert field of study]. These implications could encompass [list impacted areas or sectors]. Originality/Value: This technological article contributes to the presentation of a review of CO2 emission calculation models available in the literature and the selection of a methodology for easy application for small and medium-sized road freight transport companies.

Reinforcement Learning for EV Fleet Smart Charging with On-Site Renewable Energy Sources

In 2020, the transportation sector was the second largest source of carbon emissions in the UK and in Newcastle upon Tyne, responsible for about 33% of total emissions. To support the UK’s target of reaching net zero emissions by 2050, electric vehicles (EVs) are pivotal in advancing carbon-neutral road transportation. Optimal EV charging requires a better understanding of the unpredictable output from on-site renewable energy sources (ORES). This paper proposes an integrated EV fleet charging schedule with a proximal policy optimization method based on a framework for deep reinforcement learning. For the design of the reinforcement learning environment, mathematical models of wind and solar power generation are created. In addition, the multivariate Gaussian distributions derived from historical weather and EV fleet charging data are utilized to simulate weather and charging demand uncertainty in order to create large datasets for training the model. The optimization problem is expressed as a Markov decision process (MDP) with operational constraints. For training artificial neural networks (ANNs) through successive transition simulations, a proximal policy optimization (PPO) approach is devised. The optimization approach is deployed and evaluated on a real-world scenario comprised of council EV fleet charging data from Leicester, UK. The results show that due to the design of the rewards function and system limitations, the charging action is biased towards the time of day when renewable energy output is maximum (midday). The charging decision by reinforcement learning improves the utilization of renewable energy by 2–4% compared to the random charging policy and the priority charging policy. This study contributes to the reduction in battery charging and discharging, electricity sold to the grid to create benefits and the reduction in carbon emissions.

Exploring the drivers of ecological footprint: Impacts of road transportation infrastructure, transport tax, and environment technologies

This study explores the dynamic effects of road transportation infrastructure, transport taxes, economic growth, trade openness, and environmental technologies on the ecological footprint using three quantile regression techniques: Simultaneous, Powell, and Method of Moments Quantile Regression (MMQR). These variables are selected for their significant influence on both economic outcomes and environmental sustainability, reflecting the interconnectedness of transportation systems, government policies, and technological advancements in shaping ecological impacts. Based on panel data from 19 European countries between 1995 and 2020, the results reveal that investments in road infrastructure and higher transport taxes contribute to reducing ecological footprint. At the middle and high quantiles, advancements in environment-related technologies further decrease the ecological footprint, whereas trade openness tends to worsen ecological quality. Importantly, the relationship between GDP and the ecological footprint follows an inverted U-shape, confirming the Environmental Kuznets Curve (EKC) hypothesis across all quantiles, which suggests that economic growth can support environmental sustainability in the long run. These findings are validated by robustness checks using fully modified ordinary least squares (FMOLS), dynamic ordinary least squares (DOLS), and canonical cointegration regression (CCR) models. Key policy implications include the need for targeted investments in road infrastructure and transport tax strategies, tailored to national contexts, along with technology-driven strategies to curb environmental degradation. Lastly, the panel causality test reveals unidirectional causality from economic growth, road transportation infrastructure, and environment-related technologies to ecological footprint, highlighting their significance as short-term contributors to environmental improvement.

Transportation connectivity development strategy in the Wakatobi islands, Indonesia

This study aims to analyze connectivity or accessibility between regions in Wakatobi islands, both within and between islands, to understand the available transportation network. Based on an understanding of the dynamics of connectivity, it is expected to provide a solid foundation for the development of more efficient and sustainable transportation infrastructure in the future. A combination of qualitative and quantitative approaches is used to explore data more comprehensively and accurately. The two primary airports and several ports are still insufficient in enhancing connectivity for both the residents and tourists within the archipelago. Improving road, sea, and air transportation networks is a necessity and expectation to improve connectivity between regions. An analysis of accessibility potential provides an overview of transportation costs and expensive and long travel fares. There are several needs that need to be met in the form of the revitalization of local ports, the development of the concept of Air Buses between crossing ports, optimizing routes between airports, and the implementation of Bus/BRT (Bus Rapid Transit) on each island with feeder lines. Furthermore, the development of connectivity in Wakatobi must consider various alternative modes of transportation, increasing service frequencies, and developing supporting infrastructure. This conclusion is the basis for the preparation of a holistic and sustainable connectivity development plan in the Wakatobi archipelago.

The Correlation of the Smart City Concept with the Costs of Toxic Exhaust Gas Emissions Based on the Analysis of a Selected Population of Motor Vehicles in Urban Traffic

The intensive development of road transport has resulted in a significant increase in air pollution. This phenomenon is particularly noticeable in urban areas. This creates the need for analyses and forecasts of the scale and extent of future emissions of harmful substances into the environment. The aim of this study was to estimate the costs of the emission of toxic components of exhaust gases generated by all users of conventionally propelled vehicles travelling on a section of urban road in the next 25 years. The traffic study was carried out on an urban traffic route, playing a key role for road transport in the dimension of a given urban agglomeration. The traffic forecast for the analysed road section was based on the results of our own measurements carried out in April 2023 and external data from the General Directorate for Roads and Motorways. The results of the observations concerned six categories of vehicles for the morning and afternoon rush hours. Based on the data obtained, the generic structure of the vehicle population on the analysed section and the average daily traffic were determined. Using the methodology contained in the Blue Book of Road Infrastructure, parameters were calculated in the form of annual indicators of traffic growth on the analysed section, travel speed, and annual air pollution costs for selected vehicle categories, remembering at the same time that the Blue Book-based methodology does not distinguish between unit costs in relation to the type of emissions. The results of the study confirmed that there was an increase in the cost of toxic emissions for each vehicle category over the projected 25-year period. The largest increases were seen for trucks with trailers and passenger cars. In total, for all vehicle categories, emission costs nearly doubled from 2024 to 2046, from EUR 3,745,229 to EUR 7,443,384, due to the doubling of the number of vehicles resulting from the traffic forecast. The analyses presented here provide an answer to the question of what pollution costs may be faced by cities in which road transport will continue to be based on conventional types of propulsion. In addition, the research presented can be used to develop urban mobility transformation plans for the coming years, within the scope of the widely promoted smart city concept and the idea of electromobility, by pointing out to local authorities the direct economic benefits of these changes.

Dynamic Adaptive Charging Network Planning Under Deep Uncertainties

Charging infrastructure is the backbone of electromobility. Due to new charging behaviors and power distribution and charging space constraints, the energy demand and supply patterns of electromobility and the locations of current refueling stations are misaligned. Infrastructure developers (charging point operators, fleet operators, grid operators, vehicle manufacturers, and real-estate developers) need new methodologies and tools that help reduce the cost and risk of investments. To this extent we propose a transport-energy-demand-centric, dynamic adaptive planning approach and a data-driven Spatial Decision Support System (SDSS). In the SDSS, with the help of a realistic digital twin of an electrified road transport system, infrastructure developers can quickly and accurately estimate key performance measures (e.g., charging demand, Battery Electric Vehicle (BEV) enablement) of a candidate charging location or a network of locations under user-specified transport electrification scenarios and constraints and interactively and continuously calibrate and/or expand their network plans as facts about the deep uncertainties about the supply side of transport electrification (i.e., access to grid capacity and real-estate and presence of competition) are gradually discovered/observed. This paper describes the components and the planning support of the SDSS and how these can be used in competitive and collaborative settings. Qualitative user evaluations of the SDSS with 33 stakeholder organizations in commercial discussions and pilots have shown that both transport-energy-demand-centric and dynamic adaptive planning of charging infrastructure planning are useful.

A Study of Heavy Road Freight Transport in Poland in the Context of the Pursuit of Sustainable Road Transport

The efficiency of road freight transport determines—to a significant degree—the total environmental footprint and the amount of greenhouse gases and other pollutants released into the atmosphere by inland transport. The rate of empty or partially empty vehicles is one of the key metrics for improvement of the environmental performance of freight road transportation. This paper presents the characteristics of road freight transport in Poland on the basis of data collected by weigh-in-motion stations. Data aggregation for environmental analysis represents a novel aspect of the work. Indicators describing the degree of loading, the share of empty vehicles in traffic, and the share of vehicles of maximum permissible total weight in traffic were determined for a representative group of heavy goods vehicles. Based on the representative load factor value (LFA), a classification of the road section into four groups was proposed. The results obtained show a clear differentiation of the values of the indicators analyzed for individual groups and their variability in the three-year period covered by the analysis. The aggregation method presented can be used to identify the nature of the distribution of the weight categories of the heavy goods vehicles and provide input information for targeted analyses relating to sustainable road transport management and environmental protection. Finally, the grouped LFA values were linked with indicators of energy consumption (ECI) and on-road emissions (EI).

Label-free liquid chromatography mass spectrometry analysis of changes in broiler liver proteins under transport stress.

Transportation duration and distance are significant concerns for animal welfare, particularly in the poultry industry. However, limited proteomic studies have investigated the impact of transport duration on poultry welfare. In this study, mass spectrometry based bottom up proteomics was employed to sensitively and impartially profile the liver tissue proteome of chickens, addressing the issue of animal stress and welfare in response to transportation before slaughter. The liver exudates obtained from Ross 508 chickens exposed to either short or long road transportation underwent quantitative label-free LC-MS proteomic profiling. This method identified a total of 1,368 proteins, among which 35 were found to be significantly different (p < 0.05) and capable of distinguishing between short and long road transportation conditions. Specifically, 23 proteins exhibited up-regulation in the non stressed group, while 12 proteins showed up-regulation in the stressed group. The proteins identified in this pilot study encompassed those linked to homeostasis and cellular energetic balance, including heat shock proteins and the 5'-nucleotidase domain-containing family. These results contribute to a deeper understanding of the proteome in broiler liver tissues, shedding light on poultry adaptability to transport stress. Furthermore, the identified proteins present potential as biomarkers, suggesting promising approaches to enhance poultry care and management within the industry.

Health loss after road transport injury – new perspectives

Abstract Background Health loss in the road transport system is a major public health problem. Globally, about a fifth of all fatalities within the road transport system are represented by pedestrians, and bicyclists are the group with the highest number of severe injuries in the EU. Here we strive to add new perspectives of health loss in different road user groups examining sickness absence (SA) and disability pension (DP) and in the case of injuries after car crashes also relating them to permanent medical impairment (PMI). Methods Several register-based studies were conducted, based on microdata linked at individual level from several Swedish nationwide registers. In one study information about PMI from the insurance company Folksam was also used. In the main analyses we included all working individuals aged 20-59 years injured in a road traffic accident (pedestrians, bicyclists, car occupants, and other road users) in 2015 in Sweden and population-based matched references without any traffic-related injury. Diagnosis specific SA and DP were assessed during 1 year before and 4 years following the accident. Results A third of the traffic-related accidents involved bicyclists, 31% car occupants, 16% pedestrian, and 19% were other accidents. The excess SA days/year was elevated for all road user groups the whole study period. Excess SA due to injury diagnoses was 15-35 days/year during the first year following the accident. Among individuals injured in a car crash that reported the injury to Folksam, 2% had a new DP 2 years after the crash, and 8% had injuries resulting in PMI. A distinct trend showed that the proportion granted DP increased with increasing PMI grade. Conclusions Sickness absence is a common outcome among individuals injured in the road transport system. Together, these studies highlight the importance of preventing not only fatalities in the road transport system but also non-fatal injuries.

Reliability of Road and Rail Transportation in the Distribution of Goods Commodities on the Makassar-Parepare Route

Reliability of Road and Rail Transportation in the Distribution of Goods Commodities on the Makassar-Parepare Route

ProtAct-Us from serious injuries with long-term consequences

Abstract Battling serious injuries and long-term consequences in road traffic remains one important issue in the overall goal of resilient future road transport and its Vision Zero. Challenges of increasing personal transport in urban areas coupled with autonomous vehicles and shuttles, new mobility devices and the overall need to ensure the safety of vulnerable road users as well as all types of vehicle occupants’ require solid medical background knowledge paired with innovative engineering approaches. EU Horizon Europe is currently funding the ProtAct-Us consortium (2024-2027) that aims at protecting all Road User Groups from serious injury and long-term physical, cognitive and mental health consequences related to road crashes through innovatively interlinked research action between medical and engineering methods and approaches. ProtAct-Us works on the following goals and challenges: i) Medical data correlation, standardisation and classification of long-term consequences of road crashes; ii) Robust and reliable medical, epidemiological and engineering tools like agreed methods to collect information on long-term consequences, upgraded Human Body Models and virtual assessment methods for the extremities, head, neck and face allowing for effective countermeasure development for all road users; iii) Reduction of long-term consequences and related socio-economic cost of road crash related injuries for all road users. The ProtAct-Us solutions will influence new standards in respect of extending current injury codification system with relevant long-term aspects, allowing new physical as well as virtual safety assessment procedures and adaption of rules and regulations to be implemented. Finally, scientifically well-founded suggestion for future implementation into policy, regulatory, and standardization guidelines for an inclusive safety improvement approach for in- as well as post-crash will be provided.

Energy Consumption, Emission, Transportation Sector in Malaysia: Review on Malaysia’s Road Transport

Transportation is a major challenge for energy conservation, with road transport in Malaysia being a significant contributor to greenhouse gas (GHG) emissions. In Malaysia, traditional fossil fuels such as gasoline and diesel dominate the transportation sector, which has become the second-largest source of GHG emissions, accounting for 20% in 2014. This increase in CO2 emissions, driven by rising vehicle ownership and economic growth, underscores the urgent need for effective emission reduction strategies. The rapid growth in road transportation in Malaysia is linked to socioeconomic factors, including rising incomes and urbanization, leading to higher energy consumption and pollution. Data indicates a significant increase in vehicle registrations from 1990 to 2018, with motorcars and motorcycles being the most common. This growth, fueled by subsidies and decentralization, has exacerbated the sector’s environmental impact. The Green Technology Master Plan Malaysia 2017–2040 aims to address these issues by setting ambitious targets to enhance renewable energy, improve energy efficiency, and promote eco-friendly fuels. Key strategies include expanding public transportation, increasing the adoption of electric vehicles (EVs), and introducing alternative fuels like hydrogen. Malaysia has substantial potential to reduce CO2 emissions through initiatives such as expanding EV infrastructure, promoting natural gas vehicles, and improving public transit. Effective implementation of these strategies can significantly lower the transportation sector’s carbon footprint, contributing to a more sustainable future.

On the legality of national carbon pricing instruments alongside the new EU ETS 2

With the EU ETS 2 a new EU-wide emissions trading system is introduced that covers the greenhouse gas emission of the buildings and road transport sectors, i.e. sectors the decarbonization of which has so far been the responsibility of the Member States under the Effort Sharing Regulation. Since they will remain responsible for the achievement of their national greenhouse gas emission reduction targets under that regime, the question arises whether the Member States can maintain or introduce additional carbon pricing instruments alongside the new EU ETS 2. Hence, this paper examines the legality of such an approach, by assessing relevant provisions of EU secondary and primary law. Without going deep into the economic and political considerations, it concludes that from a legal perspective, the coexistence of national carbon pricing instruments and the EU ETS 2 is not prohibited.With the latest reform of the EU Emissions Trading System Directive (ETS Directive), the European Union (EU) has introduced a new EU emissions trading system for buildings and road transport (EU ETS 2)1. The decarbonization of those sectors traditionally falls within the responsibility of the EU Member States under the regime of the Effort Sharing Regulation (ESR). The ESR introduces legally binding national greenhouse gas (GHG) emission reduction targets. Hence, over the last few years, the Member States have introduced different measures in order to reach their targets. Those include carbon pricing instruments, understood as measures that put a price on the emission of GHG and thus create an incentive to reduce those emissions. Carbon pricing instruments include carbon taxes, as well as emissions trading systems2. With the introduction of the new ETS 2, the question arises whether the Member States can maintain (or introduce) such national carbon pricing instruments in parallel to the new EU ETS 2.

A Stochastic Approach to the Power Requirements of the Electric Vehicle Charging Infrastructure: The Case of Spain

Battery electric vehicles represent a technological pathway for reducing carbon emissions in personal road transport. However, for the widespread adoption of this type of vehicle, the user experience should be similar to that of combustion engine vehicles. To achieve this objective, a robust and reliable public charging infrastructure is essential. In Spain, the electric recharging infrastructure is growing quickly in metropolitan areas but much more slowly on roads and highways. The upcoming charging stations must be located along high-volume traffic corridors and in proximity to the Trans-European Transport Network. The main contribution of this research is to offer a method for examining the essential electricity infrastructure investments required in scenarios involving substantial electric vehicle adoption. The methodology includes a sensitivity analysis of fleet composition and market share, recharging user behavior, charging station density, and vehicle efficiency improvements. To this end, the authors have developed a simplified probabilistic model, addressing the effect of the involved parameters through a comprehensive scenario analysis. The results show that the actual number of high-capacity charging plugs on Spanish roads is significantly lower than the European regulation requirements for the year 2030 considering an electric vehicle market share according to the Spanish Integrated National Energy and Climate Plan 2021–2030 objectives and it is far from the necessary infrastructure to cover the expected demand according to the traffic flow. Under these circumstances, the charging peak power demand reaches over 7.4% of the current Spanish total power demand for an electric vehicle fleet, which corresponds to only 12% of the total.

Working conditions of commercial drivers: a scoping review of psychosocial work factors, health outcomes, and interventions

BackgroundPsychosocial work factors significantly influence both organisational and worker health. Poor management of these factors can create precarious working conditions, risking drivers’ health. This review maps evidence on the health impact of these factors and health interventions targeting the working conditions and unhealthy habits of commercial drivers.MethodThe search was conducted in four main databases (PubMed, Central, JSTOR and Dimensions Ai) and other sources like Google Scholar. In All, 28,039 articles were retrieved and through a rigorous screening process, 68 records were included in this scoping review.ResultsThis review found that drivers work in precarious conditions like long driving hours, low job resources and social support, low job control, poor remuneration, workplace abuse and sexual harassment, work-family conflict, lone driving hour, irregular shift work, lack or insufficient breaks during work hours and difficult access to social protection and sanitation facilities. These precarious working conditions may expose drivers to mental health issues, cardiovascular diseases, HIV/AIDs, stroke, chronic fatigue, kidney and bladder issues and musculoskeletal pains. Most health promotion interventions target behaviour at the individual level, such as the benefits of a healthy diet and exercise, with little effort to improving working conditions.ConclusionEmployers in the road transport sector need to implement health promotion interventions that focus on drivers’ well-being. Additionally, improving working conditions and enforcing occupational health and safety standards in the road transport sector are essential for creating a safe and healthy workplace for all commercial drivers.

Full Road Transport Sector Transition Towards 100% Autonomous Renewable Energy Supply in Isolated Systems: Tenerife Island Test Case

Full Road Transport Sector Transition Towards 100% Autonomous Renewable Energy Supply in Isolated Systems: Tenerife Island Test Case