A Survey of Home Energy Management Systems

in Future Smart Grid Communications

By Muhammad Ishfaq Khan

Summary

• Abstract• Introduction• Home energy management and monetary cost

minimization• HEM system architecture in smart grid• Challenges for smart grid• Conclusion

Abstract

• A systematic review of home energy management schemes in smart grid.

• Home energy management improves the electricity consumption efficiency at home.

• Beneficial both for consumers and utilities.• Different pricing schemes combined with

distribution generation are part of home energy management.

• HEM system architecture and challenges for smart grid to implement it.

Introduction

• A system with all or some of the following four capabilities i.e. power generation, transmission, distribution and control is called as electricity grid or power grid.

• Smart grid is nothing but the integration of information and communication technologies (ICT) in traditional grid.

• Result is more automation, safe operation of appliances, safety of grid infrastructure, reliable provision of electricity.

Introduction

• With the increasing demand of electricity, the traditional grid has shown signs of inefficiency.

• Hence idea of smart grid evolved.• Smart grid has applications in consumption, distribution,

transmission, and generation of electrical energy.• Home energy management (consumption application).• Power quality monitoring strategy has been enabled by

using sensor networks in smart grid (transmission & distribution application).

Introduction

• Distributed power generation option is always there in Smart grid technology, where in-home electricity can be generated (generation efficiency).

• A consumer can use the generated power (photovoltaic, wind) locally and sell the extra power back to utility.

• The load demand in traditional grid (flat pricing rates) is comparatively high during peak periods when compared to off-peak.

• With a normal demand the utilities are able to provide power from base plants (Hydro).

Introduction

• A HEM system in smart grid enables Demand Response (DR) and Demand Side Management (DSM) programs.

• Base plants contributes less towards emission of greenhouse gases.

• With high peak demands utilities switch on peaker plants (coal and oil fired).

• Efficient consumption of electricity proves beneficial to us both socially and economically.

• The originally inelastic load demand curve needs to be altered to reduce peak load demand, energy cost and emission of GHGs.

introduction

• Demand response (DR) and demand side management (DSM) programs are employed for the purpose of energy management.

• Different optimization methods, protocols and standards have been proposed for efficient coordination of domestic appliances and DER to reduce peak load and energy usage charges.

• A continuous work in this regard is underway across the glob, at academic, industrial and at government level.

Home Energy Management and Monetary Cost Minimization

• The process of observing, controlling and conserving electricity usage in an organization/ building is termed as home energy management.

• 40% of the global power consumption is reported to be inside buildings.

• Local power generation and different pricing schemes in smart grid enhances the performance of a home energy management system.

Home Energy Management and Monetary Cost Minimization

• Figure below shows the savings of a consumer with local power generation (with feed-in) as compared to without feed-in case.

Home Energy Management and Monetary Cost Minimization

• Real time pricing, time of use pricing, day ahead pricing, critical peak pricing and inclining block rates are different pricing schemes employed in smart grid.

Home Energy Management Schemes

• Optimization-Based Residential Energy Management (OREM)

• Linear programming model to minimize electricity bill.

• Time of Use pricing.• The proposed objective function makes sure to reduce

the home energy expenses by scheduling the home appliances in appropriate time slots.

Home Energy Management Schemes

• This kind of scheduling brings delay in the operation of appliance cycle.

• Max delay is bounded to two operation cycles of appliance.

• Mathematically Dmax ≤ 2Di

Home Energy Management Schemes

• iHEM• This scheme uses appliances with communication

capability, a WSHAN, and a central EMU.• Accommodates consumer demands at times when

electricity usage is less expensive according to the local ToU tariff.

• Consumer turns on an appliance, the appliance generates a START-REQ packet and sends it to EMU.

• EMU communicates with storage unit and smart meter.• Home appliances are controlled by EMU.

Home Energy Management Schemes

• Message floe in iHEM• Without energy management 30% of load

operates in Peak hours• Reduced from 30% to 5% with iHEM.

Home Energy Management Schemes

• ACORD• ACORD scheme has been proposed to benefit from

ToU pricing and decrease energy cost.• Shift the consumer load to off-peak periods.• In-home WSNs are used for delivery of consumer

requests to EMU.• Consumers participation in the energy management

program enhances the efficiency of the scheme.• considers only the scheduling of home appliances.

Home Energy Management Schemes

• Optimal and Automatic Residential Energy Consumption Scheduler.

• Based on simple linear programming LP computations.

• The scheme is proposed for real time pricing.• The combination of price predictor and energy

consumption scheduling (ECS) device.

Home Energy Management Schemes

• Optimization problem

Home Energy Management Schemes

• The simulation results show the reduction in daily cost by solving the optimization problem by LP techniques.

Home Energy Management Schemes

• ACORD-FI• Both the home appliances and distributed

energy resources are scheduled.• Purpose is reducing the energy bill and GHG.• ACORD-FI schedules consumer requests

considering peak hours, local energy generated and other conflicting requests.

• Uses WSNs for communication between EMU, appliances and smart meters.

Home Energy Management Schemes

• Optimum Load Management (OLM) Strategy• An optimization based residential load

management strategy.• The optimization problem needs several

interests forecasting and activity scheduling by users to form an objective function.

• Various interests are local power production i.e. from solar, wind etc, load, and electricity prices for next day.

Home Energy Management Schemes

• Maximizing the objective function.• OLM can reduce energy bill by 8-22%

• Decision support Tool (DsT)• Primary aim to help users in making intelligent

decisions during their appliances operation.