• Energy Research

This study assesses the feasibility of photovoltaic (PV) charging stations with local battery storage for electric vehicles (EVs) located in the United States and China using a simulation model that estimates the system's energy balance, yearly energy costs, and cumulative CO2 emissions in different scenarios based on the system's PV energy share, assuming silicon PV modules, and 5 kWh of storage capacity. Results show that systems located in commercial or office parking lots and used for charging EVs during working hours can be a feasible solution in all locations from a technical, financial, and environmental perspective in comparison with not only gasoline-fueled vehicles but also with grid-only charging. PV shares of 50% and 75% are achievable in all locations with PV array sizes in the order of 1–1.5 kWp , whereas a 100% PV share is possible but might result in high system costs. Scenarios with PV charging and local storage show emissions reductions of 60%–93% in the USA and 28%–93% in China compared with a gasoline-fueled vehicle.

Smart energy products and services (SEPS) have a key role in the development of smart grids, and testing methods such as co-simulation and scenario-based simulations can be useful tools for evaluating the potential of new SEPS concepts during their early development stages. Three innovative conceptual designs for home energy management products (HEMPs)—a specific category of SEPS—were successfully tested using a simulation environment, validating their operation using simulated production and load profiles. For comparison with reality, end user tests were carried out on two of the HEMP concepts and showed mixed results for achieving more efficient energy use, with one of the concepts reducing energy consumption by 27% and the other increasing it by 25%. The scenario-based simulations provided additional insights on the performance of these products, matching some of the general trends observed during end user tests but failing to sufficiently approximate the observed results. Overall, the presented testing methods successfully evaluated the performance of HEMPs under various use conditions and identified bottlenecks, which could be improved in future designs. It is recommended that in addition to HEMPs, these tests are repeated with different SEPS and energy systems to enhance the robustness of the methods.

AbstractDesigning with photovoltaics (PV) is the core focus of this paper which presents the results of a design study on conceptual PV applications for electric mobility systems. This is a relevant direction for new product development because PV technology can contribute to improved features of electric mobility systems not just in terms of CO2emissions reduction but also regarding product aesthetics and user experiences. Design studies are multidisciplinary by nature; therefore, in this case technical, user, regulatory and aesthetic aspects are covered. Eleven conceptual designs were developed in 2019 by means of a design project executed at the University of Twente, encompassing solutions for PV‐powered charging of electric vehicles, vehicle‐integrated PV products and other applications. The concepts focus on various modes of transport beyond passenger cars such as public transportation, electric bicycles and utility vehicles, in some cases applying alternative charging technologies such as battery swapping and induction charging in their design. In this paper four of these conceptual designs are presented as case studies, showing their multidisciplinary focus as well as parts of the design process behind their development. An evaluation of these conceptual designs revealed several design challenges that need to be addressed in their development, including the limited space available for integrating PV cells, the technical limitations posed by some of the proposed charging methods and the effective visual communication of the concept's intended function.

AbstractElectric vehicles (EVs) are becoming an increasingly attractive option to effectively and economically efficiently reduce global fossil fuel consumption as well as CO2 emissions associated with road transportation. In general, the grid provides the electricity required to charge an EV's battery. However, it could be worthwhile to consider EV charging by specific solar photovoltaic (PV) systems to further facilitate the use of renewable energy and to minimize CO2 emissions. Additional benefits could, for instance, be less overloaded local grids and additional grid flexibility. Because little information and experiences exist with so‐called solar PV‐powered EVs, this paper explores how well PV systems—with the possible combination of battery energy storage systems (BESSs)—might contribute to charging of EVs in four different countries, namely, The Netherlands, Norway, Brazil, and Australia. To this end, a model has been developed that calculates the interactions between PV‐BESS systems, EVs, and the grid in each country to determine the electricity balance, financial consequences, and avoided CO2 emissions of PV‐powered EVs, compared with EVs that are solely charged by the grid, as well as conventional passenger cars with an internal combustion engine (ICE‐V). It is logically found that in countries with a high irradiation, the whole year through, such as Brazil and Australia, solar PV‐powered EVs can be operated more effectively than in countries with a high variability of irradiation over the year such as The Netherlands and Norway. If the charging system's PV share is increased from 0% to 50%, the number of required grid charging events per year can be reduced from 104 to 34 in The Netherlands and from 123 to 55 in Norway. PV charging can also reduce CO2 emissions of EVs by 18% to 93% as compared with ICE‐Vs depending on the location. From a financial perspective, PV‐powered EVs are not yet financially feasible in all countries; however, in some nations, 100% PV charging is already a viable option. In general, it can be concluded that in contrast to driving an ICE‐V, the further PV‐powered EVs are driven, the more affordable they become—they might even generate financial revenues—and hence, the higher their positive environmental impact will be.On the basis of this study, it can therefore be concluded that solar PV‐powered EVs are a technically feasible and increasingly financially attractive option for transport sector emission reductions in most countries when compared with regular grid charging of EVs and certainly as compared with ICE‐Vs.