Load flexibility of household customers with real time consumption data and automatic control of electric heating systems

Smart Customer Gotland is the market test within research and development project Smart Grid Gotland. The market test comprises almost 300 customers with electric residential heating, such as water boiler, electric heater, direct electric heating, electric floor heating and/or heat pump. About 50 of these customers are, in similarity to the larger part of the group, equipped with technical equipment for real time monitoring of the electricity consumption but lack the additional equipment for control of the heating system. The price signal consists of a reinforced spot exchange price for electric power, time of use grid tariff and a wind component, uniquely designed Smart Customer Gotland, in order to increase the Demand for electricity in situations of high production. The primary ambition with the market test was to offer a technical and economic solution that attracts a large number of participants. The market test should give an active customer possibility to save money by shifting load towards periods when electricity are cheaper. The load shift should, at least theoretically, correspond to the overall goal of the project - to increase of Gotland's capacity to host renewable power production. The market test started in late autumn 2013 and has, according to midterm analyses, so far been a veritable success. It still is too early to make statements on changes in consumption on a household level. But on an aggregated level it is clear that the consumption is both lowered and has shifted towards low price periods. The involvement and appreciation of the participating customers has exceeded every expectation. A large part of the customers has decided to keep the service, including the technical equipment, at own expense, after the end of the project. This paper will discuss the market test from a load flexibility view point - how to attract, maintain and decommission active customers and expected level of activity of different categories of customers. The paper will also include positive experiences, such as sudden increase in customer satisfaction index, and challenges, such as high demand for technical support.