• Energy Research

The Leaf Roof project on the design features of PV roof tiles using Luminescent Solar Concentrator (LSC) technology [1] has resulted in a functional prototype . The results are presented in the context of industrial product design with a focus on the aesthetic aspects of LSCs [2]. This paper outlines the design of Leaf Roof tiles under consideration of simulation results, experimental measurements on dyes’ absorption spectra, and the energy performance of Leaf Roof elements in the context of their geometry and colors. 32nd European Photovoltaic Solar Energy Conference and Exhibition; 2730-2734

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.

This paper focuses on the reliability of electricity supply at three different locations in Indonesia, namely in Sumatra, Timor, and Papua, through a comparison of reported indices of power reliability (SAIFI and SAIDI) and experimental results from user surveys and power measurements. The reason for this study is the lack of information about the actual, quantified reliability of power supplied by the main grid in Indonesia, while narratives of end-users indicate the reliability might be unsatisfactory. The study was executed using data from 114 randomly-selected respondents in the city of Pekanbaru in Sumatra, 65 in the city of Kupang in Timor and 26 in the city of Jayapura in Papua, totaling 205 respondents. These users experienced a higher unavailability of power delivered by the grid than expressed by the utility-reported SAIDI and SAIFI. Therefore, for this study, new indices are introduced, namely the Perceived (P) SAIDI and SAIFI, which are based on the frequency and duration of blackouts experienced by the users. It is concluded that the reported reliability indices do not always demonstrate the experience of the grid users. P-SAIFIs were 1.3 to 4.6 times higher in Pekanbaru and Kupang, respectively than the utility-reported SAIFIs for the same provinces. Also, P-SAIDIs were 2.6 to 3.9 times higher in Pekanbaru and Kupang, respectively, than the utilities’ SAIDIs. It is therefore not surprising that depending on the location, 14% to 65% of the users own a backup generator and that households are willing to pay $3 to $8 extra per monthly electricity bill or $1c–$3c per kWh for improved reliability.

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.

This paper describes a new software tool named "VR4PV," which has been developed for real-time simulation of irradiance for photovoltaic (PV) products in a virtual 3-D environment. This tool offers the possibility for product designers and architects to evaluate the distribution of irradiance on surfaces with an arbitrary geometry that can be covered with PV cells. In addition, the energetic performance can be estimated during the design process of PV products and building integrated PV (BIPV). The software allows for irradiance calculations on multiple arbitrarily oriented surfaces at the same time. It includes shadow simulation for multiple surrounding objects with various shapes and can handle movements of the 3-D objects during the simulation, which might be useful for the design of moving PV-powered products like boats, cars, and portable handhelds. A validation is carried out based on 1-min outdoor measurements of irradiance on two different locations in Italy and in California.

In this paper an experimental research is presented on a new use of Phase Change Materials (PCMs) in concrete floors, in which thermal energy provided by the sun is stored in a mix of concrete and PCMs. When this thermal energy is being released – in moderate sea climates during the evening and early night – it is aimed to reduce the need for thermal energy of conventional heating in houses. The temperatures of four concrete floors in closed environments were monitored to reflect on the influence of PCMs and type of insulation in relation to ambient temperatures and solar irradiation. The application of PCMs in concrete floors resulted in a reduction of maximum floor temperatures up to 16 ± 2% and an increase of minimum temperatures up to 7 ± 3%. The results show the relevance of an integral design in which the thermal resistance of the building shell, the sensible heat capacity of the building and the latent heat capacity of the PCMs are considered simultaneously.

AbstractThis paper gives an overview of the status of implementation of photovoltaic (PV) systems among 34 member countries involved in the COST Action PEARL PV in the year 2018. Besides this, influencing factors that have an impact on the implementation of PV systems in each country have been assessed. The implementation of PV systems varies in European countries due to differences in solar irradiation and weather conditions, electricity consumption, national economic situation, and governmental approaches to promote PV. For this paper, data sets covering, among others, numbers installed PV systems, and the variables mentioned above, were collected, processed, and synchronized. Subsequently, relations between data were analyzed by geographic mapping and mutual correlations. The 34 countries evaluated produced together 120 TWh of PV electricity in 2018. It was notable that Germany produced the highest amount (45 TWh) and has the highest share (8.4%) of PV in its electricity generation. Weak correlations were found between the different variables and the gross domestic product, annual global irradiation, number of subsidy schemes, cumulative installed capacity, annual electricity generated by PV, the share of RE, and share of PV. Logically, as expected, strong correlations (R2 = 0.9) were found between the number of inhabitants and the annual electricity production and consumption. From our analysis, we conclude that four different groups of countries can be identified to categorize the usability of PV. One type covers countries with a significant unused PV potential while local–global irradiation is redundantly available, such as Turkey, Spain, Cyprus, Portugal, and Israel.