Decentralized distributed clean-energy sources have become an essential need for smart grids to reduce the harmful effects of conventional power plants. Smart homes with a suitable sizing process and proper energy-management schemes can share in reducing the whole grid demand and even sell clean energy to the utility. Smart homes have been introduced recently as an alternative solution to classical power-system problems, such as the emissions of thermal plants and blackout hazards due to bulk plants/transmission outages. The appliances, sources and energy storage of smart homes should be coordinated with the requirements of homeowners via a suitable energy-management scheme. Energy-management systems are the main key to optimizing both home sources and the operation of loads to maximize home-economic benefits while keeping a comfortable lifestyle. The intermittent uncertain nature of smart homes may badly affect the whole grid performance. The prospective high penetration of smart homes on a smart power grid will introduce new, unusual scenarios in both generation and loading. In this paper, the main features and requirements of smart homes are defined. This review aims also to address recent proposed smart-home energy-management schemes. Moreover, smart-grid challenges with a high penetration of smart-home power are discussed.
Smart homes provide comfortable, fully controlled and secure lifestyles to their occupants. Moreover, smart homes can save energy and money with the possibility of profiting from selling clean renewable energy to the grid. On the other hand, the probable decrease in total domestic-energy loads encourages many governments to support promising smart-home technologies. Some countries have already put out many rules, laws and subsidy programmes to encourage the integration of smart homes, such as encouraging the optimization of the heating system, supporting building energy storage and/or deploying smart meters. For instance, the European Standard EN 15232 [ 1] and the Energy Performance of Building Directive 2010/31/EU [ 2], which is in line with Directive 2009/72/EC as well as the Energy Road Map 2050 [ 3], encourage the integration of smart-home technologies to decrease power demand in residential areas.
To control the environment, a smart home is automated by controlling some appliances, such as those used for lighting and heating, based on different climatic conditions. Now, recent control schemes adapt many functions besides classical switching ones. They can monitor the internal environment and the activities of the home occupants. They also can independently take pre-programmed actions and operate devices in set predefined patterns, independently or according to the user’s requirements. Besides the ease of life, smart homes confirm efficient usage of electricity, lowering peak load, reducing energy bills and minimizing greenhouse-gas emissions [ 4, 5].
Smart homes can be studied from many points of view. The communication systems [ 6], social impacts [ 7], thermal characteristics [ 8], technologies and trends of smart homes [ 9] are reviewed individually. Moreover, the monitoring and modelling of smart-home appliances via smart meters are reviewed for accurate load forecasting, as in [ 10, 11]. Recently, power-grid authorities have modified residential electrical tariffs to encourage proper demand-side management by homeowners. Different from previous reviews, this paper introduces smart homes from the electrical/economic point of view. It also discusses smart-home energy-management systems (SHEMS) in two different modes, offline load scheduling and real-time management. The prospective impacts of unusual smart-home power profiles on future smart grids are also summarized.
After this introductory section, Section 1 describes the different definitions of smart homes within the last two decades. Smart-home communication schemes and other infrastructures of smart homes are discussed in Section 2. Section 3 discusses in more detail the existing functions of SHEMS, their pre-proposed optimization techniques and related technical/economical objective functions. The impacts of smart homes on modern grids are also discussed in Section 4. Finally, in Section 5, the main conclusions and contributions of the paper are highlighted.
The term ‘smart home’ has been commonly used for about two decades to describe houses with controlled energy schemes. This automation scheme confirms easier lifestyles for homeowners than normal un-automated homes, especially for elderly or disabled persons. Recently, the concept of ‘smart home’ has a wider description to include many applications of technologies in one place.
Sowah et al. [ 12] define smart homes as: ‘Houses that provide their occupants a comfortable, secure, and energy efficient environment with minimum possible costs regardless their occupants.’ The Smart Homes Association defines a smart home as: ‘The integration of technology and services through home networking for a better quality of living’ [ 13].
Makhadmeh et al. define them as: ‘Incorporated residential houses with smart technology to improve the comfort level of users (residents) by enhancing safety and healthcare and optimizing power consumption. Users can control and monitor smart-home appliances remotely through the home energy-management system (HEMS), which provides a remote monitoring system that uses telecommunication technology’ [ 14].
Smart homes can be defined as: any residential buildings using different communication schemes and optimization algorithms to predict, analyse, optimize and control its energy-consumption patterns according to preset users’ preferences to maximize home-economic benefits while preserving predefined conditions of a comfortable lifestyle.
Distributed clean energy generated by smart homes provides many benefits for prospective smart grids. Consequently, the effects of smart homes on future power grids should be extensively studied. In the near future, smart homes will play a major role as a power supplier in modern grids, not only as a power consumer.
The general infrastructure of smart homes consists of control centres, resources of electricity, smart meters and communication tools, as shown in Fig. 1. Each component of the smart-home model will be discussed in the following subsections.
Infrastructure of SHEMS source
