• Energy Research

The goal of the research is to assess the minimum requirement of fast charging infrastructure to allow country-wide interurban electric vehicle (EV) mobility. Charging times comparable to fueling times in conventional internal combustion vehicles are nowadays feasible, given the current availability of fast charging technologies. The main contribution of this paper is the analysis of the planning method and the investment requirements for the necessary infrastructure, including the definition of the Maximum Distance between Fast Charge (MDFC) and the Basic Highway Charging Infrastructure (BHCI) concepts. According to the calculations, distance between stations will be region-dependent, influenced primarily by weather conditions. The study considers that the initial investment should be sufficient to promote the EV adoption, proposing an initial state-financed public infrastructure and, once the adoption rate for EVs increases, additional infrastructure will be likely developed through private investment. The Spanish network of state highways is used as a case study to demonstrate the methodology and calculate the investment required. Further, the results are discussed and quantitatively compared to other incentives and policies supporting EV technology adoption in the light-vehicle sector.

The goal of the research is to assess the minimum requirement of fast charging infrastructure to allow country-wide interurban electric vehicle (EV) mobility. Charging times comparable to fueling times in conventional internal combustion vehicles are nowadays feasible, given the current availability of fast charging technologies. The main contribution of this paper is the analysis of the planning method and the investment requirements for the necessary infrastructure, including the definition of the Maximum Distance between Fast Charge (MDFC) and the Basic Highway Charging Infrastructure (BHCI) concepts. According to the calculations, distance between stations will be region-dependent, influenced primarily by weather conditions. The study considers that the initial investment should be sufficient to promote the EV adoption, proposing an initial state-financed public infrastructure and, once the adoption rate for EVs increases, additional infrastructure will be likely developed through private investment. The Spanish network of state highways is used as a case study to demonstrate the methodology and calculate the investment required. Further, the results are discussed and quantitatively compared to other incentives and policies supporting EV technology adoption in the light-vehicle sector.

Abstract This paper presents a cost-benefit analysis for the bi-directional functionality of plug-in electric vehicle charging, often called vehicle-to-grid. Plug-in electric vehicles represent an opportunity to reduce emissions from transportation, improve the efficiency, and also, it is a solution for storing electricity from the grid. The research is focused on the vehicle-to-home application for plug-in electric vehicles, which entails a bi-directional energy flowing from vehicles to households. The benefits from this use of the plug-in electric vehicles batteries are peak-shaving as well as valley-filling on the load curve, resulting in cost reductions for the user and the electric power system. In the case of islands, the use of this storage would allow an increased penetration of renewable energy sources and a reduction of costs. The research discusses the impact of vehicle-to-grid for the Canary Islands, where a plug-in electric vehicles penetration charging higher than a 20% would cause changes to the current demand curve peaks. The results show the benefits to both the system operator and the users, which may reduce mobility energy costs by a 50% through the time of usage. Vehicle-to-home regulation based on standards is recommended for incentivizing its functionality, the time of usage pricing, based on market prices, being the most beneficial for the user and the electric power system as a whole.

Abstract This paper presents a cost-benefit analysis for the bi-directional functionality of plug-in electric vehicle charging, often called vehicle-to-grid. Plug-in electric vehicles represent an opportunity to reduce emissions from transportation, improve the efficiency, and also, it is a solution for storing electricity from the grid. The research is focused on the vehicle-to-home application for plug-in electric vehicles, which entails a bi-directional energy flowing from vehicles to households. The benefits from this use of the plug-in electric vehicles batteries are peak-shaving as well as valley-filling on the load curve, resulting in cost reductions for the user and the electric power system. In the case of islands, the use of this storage would allow an increased penetration of renewable energy sources and a reduction of costs. The research discusses the impact of vehicle-to-grid for the Canary Islands, where a plug-in electric vehicles penetration charging higher than a 20% would cause changes to the current demand curve peaks. The results show the benefits to both the system operator and the users, which may reduce mobility energy costs by a 50% through the time of usage. Vehicle-to-home regulation based on standards is recommended for incentivizing its functionality, the time of usage pricing, based on market prices, being the most beneficial for the user and the electric power system as a whole.

This paper presents a novel methodology for assessing islanding microgrids from the economical and functional perspective, for various stakeholders. The paper proposes the triggers for competitive deployment of microgeneration, storage, microgrid islanding, the market conditions that apply, and discusses the future tendencies and the policy recommendations to foster microgrid benefits. The validation of the proposed scheme is based on real market cases, where the triggers for autogeneration and islanding microgrids are present. Additionally, the new concept of grid independence cycle is presented and analyzed. The policy implications of a situation where grid consumption reduction leads to higher energy prices are presented and discussed. The paper concludes with a summary of prioritized technical and regulatory recommendations, proposed as a result of the assessment.

This paper presents a novel methodology for assessing islanding microgrids from the economical and functional perspective, for various stakeholders. The paper proposes the triggers for competitive deployment of microgeneration, storage, microgrid islanding, the market conditions that apply, and discusses the future tendencies and the policy recommendations to foster microgrid benefits. The validation of the proposed scheme is based on real market cases, where the triggers for autogeneration and islanding microgrids are present. Additionally, the new concept of grid independence cycle is presented and analyzed. The policy implications of a situation where grid consumption reduction leads to higher energy prices are presented and discussed. The paper concludes with a summary of prioritized technical and regulatory recommendations, proposed as a result of the assessment.

Abstract The purpose of this paper is to prove as possible the improvement of the efficiency of a photovoltaic power plant, if it could be installed on top of a water canal, and how this facility could at the same time improve the efficiency of the water canal. The Tajo-Segura water transfer located in Spain has been chosen as the scenario for this research paper. The use of a water canal for this type of photovoltaic facility involves several problems. For example, it is very important that under no circumstance should any change on the canal structure affect the main end-use purpose of the hydraulic infrastructure (to channel water). Moreover, these facilities are strongly linear structures, so there is a problem connecting the electricity to the network. Nevertheless, these problems could be solved or minimized by applying different technical solutions, and if optimal synergies between infrastructures were obtained. It should be taken into account that the water facilities, which are already on service, save a significant quantity of water, and that these savings are achieved while avoiding the evaporation produced by direct solar radiation. The facility in this study can increase its efficiency, thanks not only to the optimal positioning to avoid the shadow between panels but also because panels can be cooled with the water that the canal contains. Focusing on these improvements, different types of technology implementation have been studied, concluding that the best option is the fixed system technology. A special methodology to geometrically place the photovoltaic panels has been developed. A proposal for novel cooling is also included in this work. The results of this study show that the project could be developed with an investment of 248 M€. Through the power generation and the savings in canal water resources, the investment could be repaid in approximately 15 years. The contribution of this work is the demonstration of the technical and economic interest of the optimal configuration analyzed.

Abstract The purpose of this paper is to prove as possible the improvement of the efficiency of a photovoltaic power plant, if it could be installed on top of a water canal, and how this facility could at the same time improve the efficiency of the water canal. The Tajo-Segura water transfer located in Spain has been chosen as the scenario for this research paper. The use of a water canal for this type of photovoltaic facility involves several problems. For example, it is very important that under no circumstance should any change on the canal structure affect the main end-use purpose of the hydraulic infrastructure (to channel water). Moreover, these facilities are strongly linear structures, so there is a problem connecting the electricity to the network. Nevertheless, these problems could be solved or minimized by applying different technical solutions, and if optimal synergies between infrastructures were obtained. It should be taken into account that the water facilities, which are already on service, save a significant quantity of water, and that these savings are achieved while avoiding the evaporation produced by direct solar radiation. The facility in this study can increase its efficiency, thanks not only to the optimal positioning to avoid the shadow between panels but also because panels can be cooled with the water that the canal contains. Focusing on these improvements, different types of technology implementation have been studied, concluding that the best option is the fixed system technology. A special methodology to geometrically place the photovoltaic panels has been developed. A proposal for novel cooling is also included in this work. The results of this study show that the project could be developed with an investment of 248 M€. Through the power generation and the savings in canal water resources, the investment could be repaid in approximately 15 years. The contribution of this work is the demonstration of the technical and economic interest of the optimal configuration analyzed.