Fixed cost components, such as the surcharge levied under the German Renewable Energy Act (Erneuerbare Energien Gesetz, or EEG) dominate tariffs paid by the end user. This has reduced the ability of spot prices to influence demand side management. Further on, on-site generation and associated self-consumption are currently granted by avoided tariff payments. This means that on-site generation operates independently from the market situation unless market prices drop below zero. Within this project the effects to demand response and self-generation studied if today’s renewable surcharge will differ by time, related to the day-ahead wholesale market prices.