There are currently 1,8 million photovoltaic (PV) installations across Europe and the volume traded of operational installations (secondary market) is assumed to be more than €1,5 billion annually. Yet before Milk the Sun came into play, there was no appropriate marketplace available in Europe. Therefore we have created an online platform, which enables all industry participants to trade their installations online. Milk the Sun offers a unique online marketplace, where every player on the PV market can register and search for relevant business partners. This includes equally land/ rooftop owners who want to trade project rights (primary market), owners of PV systems who want to resell their operational installations (secondary market) as well as investors searching for new opportunities for profit-making. Moreover, service features are available guiding solar projects from the launch until closing such as insurance calculator, legal services and yield optimisation. Milk the Sun aims at making the European photovoltaic market transparent and efficient.