Interoperability in AMI and the smart grid

Sharon Allan mag

Sharon Alan, President, Elster Integrated Solutions

As President of Elster Integrated Solutions, Sharon Allan is responsible for the company’s overall business and growth strategy involving the development, operations and support of smart metering systems and solutions that enable the smart grid, environmental sustainability and consumer empowerment. One of the key issues facing utilities and vendors as they develop and deploy advanced metering infrastructure and smart grids is interoperability between the various system components.

What is interoperability?
The whole thrust around interoperability is gaining the ability for systems and different products to work together seamlessly. At the simplest level there are three types of interoperability – the ability for devices to work with each other, the ability for systems to work with each other, and the ability for subsystems to work within one system.

Perhaps the simplest analogy is with cellphones. Here in North America there are two competing standards, GSM and CDMA. I have an AT&T phone, which is GSM, and I can call a Verizon phone, which is CDMA, and we can link and talk. In other words those two systems can interoperate and communicate, even though the underlying subsystems are based on different standards. But you can’t take a Verizon phone and get it to work on the AT&T network. So at the device level they do not interoperate; at the application level they do interoperate.

Within the smart grid there are several different layers. There are devices – sensors, meters; there are networks – private wireless, wire-line, GSM, CDMA; and there are head end systems and servers – maybe Microsoft, Oracle, Windows or Unix-based. The goal is to create layers of interoperability such that the system operation is transparent. If an operator has a query, he wants to send the query and have it go all the way through the subsystems to the devices and receive a response, without worrying about whether the system is run on Unix or Windows, whether the query goes out by phone line or wireless, and whether it goes to an Elster device or some none- Elster device.

What are the various elements of interoperability?
There are five elements, the first of which is the business process interface. For example, within North America there is the standard MultiSpeak, which is now being rationalised into a standards body with CIM (common information model), so that no matter whose outage management system is used – Milsoft, Oracle, or ABB – the data coming out of the AMI system will work with it.

Next is service delivery, or how one gets that data across networks, whether wired or wireless or across a power line.

The third is security. There are a lot of different security standards. For example, a user doesn’t want to be able to get data up from the application but not have access to it because the encryption mechanisms are different from those used by the person who encrypted it.

The fourth is information exchange and the common ways to interpret the underlying formats.

The last is interconnections. For example, in a meter there are defined tables, whether ANSI or IEC, but if the data is not stored in one of these tables or if a manufacturer’s table is used, then when the data is outputted it has to be interpreted differently depending on the manufacturer.

What does interoperability for smart grid systems mean?
All these elements are applicable whether in the energy space talking about smart grid, the internet space talking about the web, or the telecoms space talking about wires or wireless communication.

The main challenge of interoperability is that people think that if one has standards compliance, one automatically has interoperability. But there are many different standards – in communications something like 21 standards. Within standards there are also often many different options and interpretations, so that implementations will be different.

What does it take for two devices from different vendors to work together?
To get two devices to work together usually requires collaboration between manufacturer A and manufacturer B agreeing to a common set of rules on how to exchange data such that each party can interpret it.

At the application level there is an effort being made on many fronts to try to define some of that but it is a work in progress and one that will continue to evolve as there will be new applications and functions that we will want in the future.

Within the smart grid world most of the Request for Proposals that come out have a plethora of standards with which to comply. As a developer, when developing our software interfaces we have tried to embrace whatever application standards exist since everyone can implement the interface the same; the customer gets choice but we as a developer only need to develop it once.

Why do we need industry standards?
The real goal behind industry standards is to enable and help foster interoperability as if one doesn’t have them. Within our industry we have to embrace things that have come from other industries. ZigBee communication technology, for example, was not designed for the energy space but is now considered in terms of consumer empowerment in home area networks.

We started working about 18 months ago with various partners, one doing a ZigBee display, another doing a load control device, and a third a thermostat. None of the three devices could talk to each other because they all implemented ZigBee differently. What has now progressed through a collaboration of many parties in the market is a set of rules, known as the Smart Energy Profile, with the goal of interoperability.

Last summer we worked on pilots with two large investorowned utilities with the intent of having smart energy profile enabled devices. However, in talking to the customers they wanted things in support of their programmes that the smart energy profile did not define. As a result, Elster had to work with the customers to accomplish what they wanted using ZigBee. This is also how standards evolve.

What is an open standard and why is this important?
There are two ways to have standards. One is to have standards agreed upon by an official body, such as the IETF or IEEE, and the other is to have de facto standards such as http for the internet, which was not officially governed and sanctioned.

When people refer to open standards, often they refer to standards that are readily available without licence or restrictions on use. But open doesn’t necessarily mean free and it doesn’t necessarily mean there isn’t associated intellectual property. For example, the CDMA standard is an open standard as it is used by different manufacturers, but it is owned by Qualcomm to whom a royalty fee is paid for use.

Open is giving access to people to use a standard. This is important because it means a company isn’t risking the possibility of being locked into a particular vendor. In the smart grid, for example, if the only person who could make a voltage sensor for a particular network is the network provider who sold it, then there would be a concern if he were charging too high a price or went defunct. It is ultimately a risk mitigation strategy.

What are the effects of open standards?
The goal is to provide choice. For example, if I want to buy an ABB outage management system with an Itron meter data management system with an Elster AMI network with a Landis+Gyr meter, I want to be able to do that, rather than having to buy everything from one vendor.

Which industry stakeholders will benefit from industry standards?
The stakeholders really encompass everyone. The customers benefit as they are given choice. The vendors benefit as their development time is cut. And the end customers – the customers of the utilities – whose tax dollars ultimately pay for these systems will benefit, as with systems that work together out of the box the total system cost is reduced.

What are the barriers to creating a truly interoperable communications system?
Standards aren’t static and they continue to change. Also, in looking at delivering particular extra value options or added efficiencies that are very specific to a customer or partners, it becomes a tradeoff between having something common for everyone versus being more value driven for particular applications. This can become a barrier if one is gearing around helping a utility use as many of its given assets rather than write everything off the books. One never walks into a job with a clean slate to change out everything in the enterprise, so there is a natural barrier in trying to get everything working with the legacy that already exists.

What will it take to have full interoperability?
All of us who participate in the market today realise we must work with each other.

As a company, we have signed agreements with our competitors. We are active in a number of different standards organisations, we are active in the application interfaces under CIM, and we have got our products MultiSpeak compliant, we are participating in various market gathered areas around security, HAN development; we are a member and participate within the ZigBee Alliance. Around the smart grid, the company is a participant and active in the GridWise Alliance.

I would say no company can afford to do business in the market today without participating in how we collaborate.

Looking to the future, I believe there is a need for test harnesses and test scenarios to ensure that it all works together.

This is the first in a series launched by Smart Energy International to provide a space in which industry executives can share their thought leadership. For enquiries about utilising this space, please contact Priscilla Bryson, VP Publishing, on