Smart homes: potentials and challenges

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.

Conventional generation emulation for power grids with a high penetration of wind power

Integrating large-scale wind plants with the electricity grids has many challenges for grid operators.Besides the variability and uncertainty of wind power,coordinating between different technologies of generation in the same grid can be considered the main problem,specifically for short-term frequency stability.Therefore,a large penetration of wind power generation in modern power grids has a risky influence on the power-system frequency.Wind-generation plants have contradictory behaviour compared to classic thermal plants,especially in active generated power-shortage events due to the variable nature of wind power.Existing experience in wind plants keeps part of the available wind power unloaded,using what are known as deloading techniques.Different deloading techniques are usually applied to emulate the thermal-plant-governor function and confirm a proper spinning reserve for any active-power shortages.These techniques decrease the generated power from wind plants continuously from maximum point tracking ones.Consequently,the practical capacity,annual generated energy and economical income of wind plants are reduced.In addition,grid-protection and control sub-schemes are set and designed according to the well-known conventional responses of thermal plants,which increase the need for thermal-plant-behaviour emulation.In this paper,instead of the usual deloading methods,a supercapacitors scheme is proposed with wind turbines to emulate the response of conventional power plants.The study discusses the technical and economic benefits of the proposed addition of supercapacitors in the wind-plant-planning phase.Restricted frequency grid-code indices are selected to evaluate studied behaviours.Simulation results of the IEEE four-generation two-area system determines the effectiveness of suggested schemes technically.The System Advisor Model(SAM)program estimates the economic benefits of a typical US study case compared with the existing wind-deloading technique.