The art of the possible a vision for the future of PLC technology for smart grid communications


By Chris Graham-Fielding

“There is no ‘single’ element in a smart grid – it is an ‘end to end’ cohesive solution. It must provide reliable and cost effective two-way communication across and between vast internal and edge assets. The UPA PLC enabled smart grid is key to delivering an ‘end to end’ cohesive solution.”

There are myriad definitions in the market as to what constitutes a smart grid, from automated metering intelligence/infrastructure (AMI) and transmission and distribution intelligence through to the inclusion of supervisory control and data acquisition (SCADA), distributed power control and demand side management.

Every utility and component or solution provider has its own view. That view and definition is influenced by factors ranging from commercial or legislative drivers, through to portfolio expertise and product or application positioning. Even individual business divisions or departments within a utility will have their own view of what a smart grid is.

In principle, the smart grid relies on gathering data from large numbers of intelligent sensors and processors installed on the power lines and equipment from around the power grid (e.g. metering infrastructure, switches circuit breakers, transformers, bus bars, etc.) and then using that information effectively to address a wide range of topics.

To utilities, a smart grid is a commercial imperative as well as a technological implementation. They see it as supporting a range of environmental targets through to managing energy consumption whilst maximising the life of existing assets. To the Universal Powerline Association (UPA), its members and its customers, it is an opportunity to collaborate and provide a wide range of capabilities and services.

Whatever the definition, it is clear and paramount that in order to serve multiple economic, commercial, legislative and environmental goals of the 21st century, regional and national electric power grids will need to be able to support and enable communication between nodes and devices in previously unimaginable detail.

The general consensus is that to achieve this, the smart grid must be capable of intelligently integrating the actions of all the components and users connected to the grid. In reality there is no single architecture or technology that will service such a broad range of requirements. Any solution needs to be capable of interoperating with both legacy infrastructures whilst addressing future technological developments.

This article is therefore about “the art of the possible” and the role that Power Line Communications (PLC) plays in developing that “end to end” communications infrastructure. It also takes a slightly UK centric view, where we have not quite reached the dizzy heights of funding levels offered by the Obama administration to implement smart grids on the same scale, although the UK government has announced that it intends to mandate smart meters for all households, with an indicative timetable for completion by end 2020 and (consciously linked in this article) the Universal Service Commitment to provide universal (up to 2 Mbps) broadband service by 2012.

A snapshot in time would place the UK at a point where government bills on a Digital Britain, a Digital Economy and the Energy Bill are in train and will set in stone the energy and communications architecture for a generation, with trials underway to validate the options available for achieving those targets.

Like everywhere else, smart meters will play an important role in the UK in the transition to a low carbon economy, and will help to meet some of the long term challenges faced in ensuring affordable, secure and sustainable energy.

As the readers of this magazine will appreciate, smart meters perform the traditional meter function of measuring energy consumption. But they also offer a range of advanced functions, such as allowing energy suppliers to communicate directly with their customers, removing the need for meter readings and ensuring accurate bills with no estimates. Consumption information can be provided to domestic customers through an integrated, in-home display.

If we take that one “not so” simple step to an AMI , then at that point the smart grid forms both a technological and commercial bridge between supplier and customer, presenting the potential for whole raft of new and “interactive” services. And that is a key point in this article.

Interactivity. Not store and forward. Not batch processing of data, but real time interaction. The art of the possible, enabled by a PLC supported smart grid.

In that instance on-line interaction means consumers will not only have more control over their own energy use and carbon emissions, but also that new opportunities will be opened up for energy retail services, infrastructure management and renewable energy generation and a host of other commercial services that will evolve over time, and can be delivered by that same infrastructure.

Digitising or “enabling” a power network with wide band or “high speed” PLC creates an “always on” network providing a constant bit stream and transport medium for data for a wide range of digital IP-based services.

We know that building the smart grid requires unprecedented collaboration, but in a market like this the collaboration will come not only from a technological and standards viewpoint. It will bring with it interoperability reaching far beyond the relationship between the utility and the meter supplier.

It is fair to say that the data rates available from wide band PLC could be considered to be far in excess of any traditional metering or SCADA architecture requirement, but when combined and associated with other applications, the cost effectiveness and benefits of a PLC-enabled smart grid supporting an AMI architecture become clear.

That always on functionality is an essential part of the smart grid network. Always monitoring, always available, always communicating, and that ethos extends beyond the electrical grid and into the property being served, so the community of interest is available to a wider audience.

As an example, look at the range of members of the U.S. Demand Response and Smart Grid Coalition. Of course there are the core and mainstream communities including meter providers, energy management organisations and service providers, but there are also organisations and household names like Whirlpool and Google as members actively providing and developing commercial solutions that will help drive the end-user experience of the smart grid.

The more applications and services, the more bandwidth and the more control and management required, and the more collaboration (both technical and commercial) needed between parties.

PLC bandwidth

Applications and services versus the required bandwidth

By promoting PLC technologies, and particularly the benefits brought by these technologies for all the relevant applications, the UPA is working to harmonise standards and regulations globally so as to achieve a level playing field for the deployment of the technologies and services based on approved international principles. To that end collaboration is key to the UPA’s philosophy of providing a forum to strengthen international cooperation to nurture and grow the emerging PLC market.

As an example, in the UK Freedom Digital Networks has an installed base of customers using PLC for both in-building and campus-wide solutions, in hotels, student accommodation, caravan parks and multi dwelling units, with services ranging from CCTV deployment to broadband delivery.

Trials have also been running on broadband over powerline (BPL) with local government in support of providing digital services to enable school children access to education networks. A fully operational community BPL service will be available this summer with PLC deployment on the electricity grid being driven by requirements of social and digital inclusion. This implementation is being heavily supported by one of the regional distribution network operators, whose goal is a watching brief from a technological and commercial perspective.

The next phase of the project is to run combined trials supporting both the deployment of local government supported broadband in parallel with the DNO smart meter and network management trials.

The objectives are not only to ensure a correlation between application requirements and the bandwidth flexibility of the PLC enabled smart grid, but also to establish operational procedures to address the potential “sharing” of assets. That should keep the accountants busy for a while!

The one thing one can be sure about is the more bandwidth that is made available, the more uses people will find for it and the greater the demand will become for services.

The network design and component interoperability is therefore key and the PLC enabled smart grid must give consideration to the range of services that it may be called upon to provide, and the adoption of standards to support that.

A ubiquitous “end to end” network is a laudable goal and undoubtedly PLC has a key role to play in the delivery of that architecture, but we believe that the smart grid is not exclusively a technology collaboration.

The smart grid is also a service collaboration where, for example, a home area network (HAN) can connect (using technologies such as PLC) to the smart grid for more than just metering.

This raises a range of issues from security to network topology and service/ support management through to return on investment and even “should the meter be the gateway to the home?” There are many solutions proposed to this area by individual companies. Collaboration is also key and an example would be the recent announcement by meter manufacturer Itron and UPA member and PLC/smart grid provider and integrator Ambient to integrate their solutions.

Alliances such as this will continue to grow as this market evolves and the UPA has a stated aim to educate decision makers, government, industry and society leaders on the place to be taken by the PLC technologies in the race to build an equitable, inclusive and global communication society.

The bottom line is that the smart grid is an “end to end” cohesive solution. It must provide reliable and cost effective two-way communication across and between vast internal and edge assets.

The UPA PLC enabled smart grid is key to delivering an “end to end” cohesive solution. Perhaps PLC should also stand for power line collaboration …