On a sunny and windy day, even in winter or spring, renewable energy is abundant. If demand is stable prices will drop. Prices will rise again as demand for energy picks up. Hence, this is an obvious case for trading opportunities. All you need is … energy storage. All so-called prosumers, short for producers and simultaneously consumers have a lot to gain if they are able to store energy when it’s abundant and cheap. Sell it when it is expensive or use it yourself if needed. Just keep an eye on the costs of energy storage. A stylish insulated carafe is a well known example of storing hot water for astonishingly long time. Insulation is key to store transformed electric energy here. Other options use kinetic energy like pumping water to a higher level and then generate electricity again when the water returns to the lower level. Of course, batteries are a simple way for energy storage as well. Costs seem to come down rapidly and less environmentally hazardous materials leave the laboratory almost every month. It is about time to consider this seriously. More and more cities have understood that energy storage can generate cash for them (Example Feuchtwangen) and appears to be a worthwhile investment for a local power generating community. For the time being my favorite energy storage is the insulated carafe. It is often the beginning of energizing conversations.