Smart Grid Demand Response with Mutual Utility-Consumer Benefits
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At present, the distribution of electricity is mostly one-way from utilities to consumers. On the other hand, communication of information such as energy consumption information for billing purpose is either a manual process for the majority of consumers or often one-way from consumers to utilities in consumers with meters capable of automated meter reading (AMR). One-way communication of information hinders efficient use of the distribution grid. This is related to the physical limitation of the distribution grid; i.e. the grid has the capacity to handle up to a certain level of power demand at a time instant. We refer to the highest level of power demand over a certain period of time as peak power demand. When consumers start using a lot of power-hungry devices like electric vehicle (EV) chargers at the same time, for example around 18:00 after coming home from work, this creates high peak power demand which could be straining the distribution grid. Because a number of consumer devices have flexible start time (e.g. washing machines, dish washer, and EV chargers) or potential to pause/postpone operation time (e.g. heater, ventilation, and airconditioning (HVAC)), it would be of great advantage if consumers would shift the start time of these devices to off-peak periods when electricity usage is low. In other words, if electricity usage timing can be influenced according to the current status of the distribution grid, it will lead to better utilization of the distribution grid and could prevent overload. To realize this, communication must be made from utilities to consumers that will stimulate consumers to adjust electricity usage and sufficient number of consumers must respond to the stimulants. Stimulating consumer responses to electricity usage adjustment is called Demand Response (DR). DR usually involves the communication of electricity prices from Distribution System Operators (DSOs) to consumers to motivate the usage of electricity during low price periods, which also implies low power demand periods. Another form of DR, usually termed incentive-based DR, provides compensation to consumers in exchange for control on the consumers’ electricity usage. One existing incentive-based DR program1 that is offered to residential consumers is called Direct Load Control (DLC), where DSOs are given the ability to remotely shut down specially equipped consumer devices during critical peak periods. DLC is effective in critical situations because prompt actions can be performed. However, various studies have shown that consumers are generally concerned about the loss of control on their own appliances and electricity usage. Moreover, many consumers prioritize their basic needs such as comfort over electricity cost saving. Because the success of a DR program depends on active participation of consumers as well as consumer satisfaction, it is important that the well-being of consumers is taken into account when designing DR programs. Aiming to respect consumers’ basic needs, this thesis proposes a consumercentric DR framework consisting of an adaptable smart home (ASH) and consumercentric DR programs that provides a means for DSOs to obtain load flexibility while maintaining consumers’ well-being. Operations and management within ASH are controlled by a Home Energy Management System (HEMS) that communicates with consumer devices and external systems (e.g. DSO and weather service). Two aspects of well-being, namely freedom and comfort, are incorporated in consumer-centric DR programs. Consumers are given freedom to use power and devices at any desired time as long as grid capacity allows. At the same time, requirements on comfort, which is defined as the satisfaction to environmental conditions in rooms and operating states of devices, are taken into account and prolonged discomfort is compensated according to the severity and duration of the discomfort.