Daniel Holstein, policy officer to German Parliamentarian Bärbel Höhn, renewed interest in demand response when he called it an “underrated resource” that is key to the Energiewende (Energy Transition) in Germany. Despite significant progress towards meeting its Energiewende goals, parliamentarians are still considering the structure and role of German power markets, particularly the role that demand response will play. Demand response is a reliable, competitive, and low-cost resource option, which other markets have effectively captured, notably the New England region of the U.S. and the Danish island of Bornholm. Holstein recommends RAP’s recent report Nachfragesteuerung im deutschen Stromsystem: die unerschlossene Ressource für die Versorgungssicherheit (available in German only) as background reading. Authors Andreas Jahn and Meg Gottstein explore international experiences with demand response in relation to reserves, regulation, capacity, and emergency response—the four pillars of system reliability. The paper also considers why demand response has seen limited implementation in the current German power system and how these barriers can be removed.