The transition of the electricity system to smart grids would require from residential endusers to adapt to a new role of co-provider or active participants in the electricity system. End-users would for instance use energy efficiently, generate renewable energy locally, plan or shift energy consumption to most favourable times (such as when renewable energy is most abundant or during low peak periods), and trade self-produced electricity with other households. In a residential smart grid, a large part of the electricity supply in households will be generated by various decentralized energy resources like wind turbines, photovoltaic (PV) solar systems and micro-cogeneration systems. In this context, smart grids are supposed to provide the opportunity to make optimal use of renewable energy by matching demand to supply conditions, thereby facilitating the energy transition towards a more sustainable and less fossil fuel dependent society.

This thesis explores the field of product-integrated photovoltaics (PIPV), a term which is used for all types of products that contain solar cells in one or more of their surfaces, aiming at providing power during the product’s use. Product-integrated photovoltaics (PIPV) began to be widely introduced around 2000, although the use of PV systems in products dates back to the 70s. PIPV includes products such as PV-powered boats, aircrafts, cars, bicycles, camping tents, street lights, recycling bins, decorative lights, PV-powered watches, calculators, PV-powered lamps, sensors, chargers, toys, low-powered kitchen appliances, entertainment appliances or PV-powered art objects. The incorporation of PV systems in products could offer various benefits, such as enhanced functionality of the product as a result of energy autonomy, and independence and freedom of use due to the absence of a connection to the electricity grid, as well as the opportunity to reduce the capacity of batteries in portable products and therefore making them more sustainable. Furthermore, photovoltaic products represent a very reliable solution for the supply of electricity in areas, which lack access to an electricity grid.

This thesis is oriented towards the development of scientific and technological knowledge about product-integrated PV (PIPV), as it focuses on the aspects that designers need to take into consideration when designing PV products. This research is interdisciplinary by nature due to its embedding in the field of industrial design engineering, regarding the technological aspects of PV technologies in products and user interaction with PV products. It combines the technical knowledge of PV technologies, indoor irradiance conditions and performance of PV cells and PV products in environments with low irradiance together with the typical behavior of users with these products and the way this behavior influences the performance of the products themselves. Besides being directed towards researchers, results of this study are useful for industrial designers who are developing PV products.