Energy Management Systems in the Home: Gateway to the Customer HAN

Zin Thein KyawSystem

Applications EngineerTexas

InstrumentsUSA

Energy Management Systems in the Home: Gateway to theCustomer HAN

Agenda

• ZigBee Smart Energy for the HAN• Overview of ZigBee Smart Energy• Example SE HAN Network• Utility HAN/Customer HAN• Scenario from HAN SRS v2.0• Example HAN with EMS• “One HAN, One Radio”• Implementation Considerations• Looking Ahead

ZigBee Smart Energy for the HAN

• Energy management in the home is trending and ZigBee SE is currently THE premier technology for adoption

• Allows users to make real-time conscious decisions about their energy usage, thus allowing them to save money

• ZigBee SE HAN represents explosive growth opportunities for wireless

• Demo showcases:• Sensus Meter• HAI In-premise display• Z-Light• Alektrona EMS with Google Power Meter support

Overview of ZigBee Smart Energy

• ZigBee Smart Energy is a ZigBee Alliance public application profile that defines commands and attributes for the following device types:• Energy Service Portal (ESI) – The ESI is the device

that acts as a gateway into the home and manages the ZigBee Smart Energy HAN

• In-Premise Display (IPD) – The IPD is a device that presents energy consumption data and price information to the end user either by text or graphical means

• Metering Device – These are typically metering devices such as gas, water, and heat meters

Overview of ZigBee Smart Energy(cont.)

• Programmable Communicating Thermostat (PCT) – Device used to control the cooling and heating systems of the home

• Load Control Device – A device such as a pool pump or water heater that is capable of receiving demand response and load control events from the utility head end

• Smart Appliance – Like a load control device, a smart appliance could be a washer, dryer, oven that is capable of receiving demand response or pricing events from the utility head end

• Range Extender – A range extender has no other purpose than to be a router device for other devices in the HAN

Overview of ZigBee Smart Energy(cont.)

• A cluster is a ZigBee term for a collection of commands and attributes specific to a particular behavior

• In ZigBee Smart Energy, the following clusters are supported:• Price – Provides functionality to convey price

information from the utility head end• Demand Response and Load Control (DRLC) -

Provides functionality for devices such as thermostats and other devices that perform load control

• Simple Metering - Provides functionality to retrieve usage data from electric, gas, water metering devices

Overview of ZigBee Smart Energy(cont.)

• Message – Provides functionality to deliver text messages• Time – Provides functionality to synchronize time between

the time server (ESP) and other devices. UTC is used as the common time base

• Key Establishment – Provides functionality for establishing a link key for secure application level communication between pairs of devices

Example SE HAN Network

• All communication with the ESI is secured at the application layer with the link key established via Certificate Based Key Establishment (CBKE)

• AES-128 block cipher is used to encrypt packets, the key is the established link key

In-Premise Display (IPD)

ProgrammableCommunicating

Thermostat (PCT)

Simple Metering Device(Gas, Water, Heat)

ESI (E-Meter)

In Premise Display shows consumption, pricesignals and text messages from ESI

ESI Sends PCT Load Control Event to control HVAC

Simple Metering Device Reports CurrentSummation Delivered Attribute Periodically

Smart Appliance

Smart Appliances shows price, textmessages from ESI

Utility HAN/Customer HAN

• The concept of “Utility HAN” and “Customer HAN” refers to the following:• Utility HAN represents devices that are owned

by the utility• Customer HAN represents devices that are

owned by the consumer• Logically thought of as “separate”, but

physically on the same network• Example scenario from the HAN SRS v2.0

document

Scenario from HAN SRS v2.0

Utility HANCustomer HAN

Example HAN with EMS

In-Premise Display (IPD)

Z-Light (LED Light)

ESI (E-Meter)

In Premise Display shows consumption, pricesignals and text messages from ESI

Energy Mangement System (EMS)

EMS retrieves meter data

Lighting Control

“One HAN, One Radio”

• The EMS in the example HAN controls both ZigBee HA (Home Automation) and SE devices

• In a lot of typical system implementations, you’ll find that there are two ZigBee radios, one to manage the HA devices, and one to manage the SE devices

• But wait, it is possible to implement this system with just one radio!

“One HAN, One Radio” (cont.)

• It is possible due to the multi-tasking architecture of TI’s Z-StackTM

• Powered by HAuSETM multi-profile support, each profile runs as a separate task, making it possible to load multiple “application device objects” in one physical device

• Applications can communicate with each other using inter-task messaging

• A simplified example is shown next

“One HAN, One Radio” (cont.)

In Premise Display Queries For Latest Pricing Info,and displays MESSAGE command from ESI

Performs Key Establishment Only

HA Lamp

SE RangeExtender

HA Switch

SE IPD

Legend

SE communication path

HA communication path

ESI

HA

SE

"Energy Management System/Gateway"

Collect Simple Metering Data

Implementation Considerations

• Security• The EMS is considered to be a trusted partner

of the utility ESI/smart meter• Any metering, pricing or load curtailing events

use the highest level of SE security• The EMS can communicate with other home

automation devices using a lower level of security since most of the communication is command and control using the HA profile

Implementation Considerations (cont.)

• Commissioning• Utilities are starting to accept the idea of

having HA devices on the same network as the SE HAN. Assumption is that the EMS is responsible for managing the customer HAN devices

• HA devices go through the same secure commissioning procedure as any other SE device

• The ZigBee Alliance is currently looking at what it would take to have future revisions of the ZigBee SE 1.x and HA specifications officially support this model

Looking Ahead

• Integration of the utility and customer HAN devices will enable a richer set of applications in the home

• Genesis of the next wave of “consumer products”

• Enable service providers to differentiate themselves by enabling varied service models

References

• ZigBee Smart Energy Profile Specification, 075356r15ZB_AMI_PTG-AMI_Profile Specification.pdf, ZigBee Alliance

• ZigBee Specification, 053474r17ZB_TSC-ZigBee-Specification.pdf, ZigBee Alliance

• Z-Stack Smart Energy Developer’s Guide, SWRA216, Texas Instruments

• HAN Use Case – General Definitions, Assumption, Actors.doc, SDG&E, SCE, PG&E

• UCAIug HAN SRS – v2.0.pdf, UCAIug – OpenSG - OpenHAN Task Force

“May the HAN be with you”