The Promise of the Smart Grid
The Smart Grid: The Advent of a New Technology Infrastructure
The need for a renovation of our electrical power infrastructure is now imperative. But in doing so, we are also creating an environment for adding creative new products and services that will represent a host of new business opportunities for the embedded industry.
TOM WILLIAMS, EDITOR-IN-CHIEF
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The concept of the Smart Grid can be described as a “many splendored thing.” In other words, it may have a basic definition, but many other ideas and assumptions arise from the notion of an intelligent power grid. That is because the electrical grid is a basic infrastructure element of modern society. The problem is that it is mostly an aging infrastructure trying to keep up with a continually advancing technological society. The increasing demand for electricity and the rapid growth of the distribution system along with generation facilities is reaching a critical stage. It is reaching a point where only the application of computer intelligence and automation will be able to maintain reliability and offer the efficiency we need to make full use of the power that can be generated.
As it turns out, the efforts to improve the grid to make it more reliable, secure, efficient and flexible are poised to create an infrastructure that will enable a whole range of innovative applications, products and services, many of which have not yet been thought of. In much the same way, the advent of the Interstate Highway System spawned motels, shopping malls, transportation companies and more; the way Microsoft Windows led to the birth of countless applications and new companies; and of course, how the advent of the Internet gave birth to a revolution in the way we live along with countless business opportunities. The birth of the Smart Grid can be expected to leverage the development of a whole new age of innovation.
According to a Department of Energy publication, the initial stages will be aimed at making today’s grid a “smarter” grid, leading eventually to the Smart Grid. The initial steps involve greatly improving reliability and giving it the ability to easily accommodate both renewable and traditional sources of energy. Among the basic infrastructure makeovers is the use of precisely timed synchrophasor data—which carries the phase relationships between voltage and current—to automatically alert the system and its operators to potential problems or failures and provide the ability to preempt them before they can cause outages. Right from the start, that involves adding data and control networking to the grid. Once such a network infrastructure is in place, there are many other applications that can take advantage of it.
Another early concept is to implement the automatic metering infrastructure (AMI), which involves the use of smart meters that can be read wirelessly. Since smart meters also provide wireless access for things like firmware updates, they also constitute nodes in a network with the attendant opportunities for access by other applications as well as security issues to prevent cyber attacks. Also, throughout the network, equipment is to be refitted with intelligent electronic devices (IEDs) that can send status data and receive control commands from supervisory control and data acquisition (SCADA) systems. Such systems can be under a combination of human control via HMI interfaces as well as automated systems that can react to predetermined conditions. The addition of networking to the grid infrastructure creates the possibility of interoperability between different systems and devices on the grid (Figure 1). That opens the possibilities of a huge number of applications.
The network that connects homes and other facilities via the smart meter extends to a wide number of systems, devices and facilities that can operate with each other automatically and/or be monitored and controlled by human operators at control centers or via the Cloud. (Courtesy of the Smart Grid Interoperability Panel)
Even this broad-brushed characterization of the Smart Grid helps indicate the potential for improving its reliability and efficiency as well as its potential to accommodate innovative applications and services as well as to accept alternate and renewable sources of power generation. These primarily come in the form of wind generation and photovoltaic sources.
Wind generation usually comes from concentrated wind farms, which are centralized facilities in much the same way as traditional fossil fuel and nuclear facilities in that power must be transported from the plant and distributed over the grid. The issue with wind is that it can be fairly constant, but does not necessarily fall off at night when demand is much lower. The challenge here is to be able to store wind energy that is generated at off-peak hours so that it can be used when demand is higher. One possible approach being suggested is to take advantage of the predicted growing number of electric vehicles (EVs) that will mostly be charging at night. More about EVs below.
The large scale use of photovoltaics, or solar panels, presents a different set of challenges and has triggered a debate about the merits of large-scale central solar power facilities versus widely distributed photovoltaic systems, for example, across the rooftops of a city or multiple cities. Since solar panels do not produce energy at night, there is the reverse situation to wind. Also, solar panels are subject to variations in cloud cover. That can lead to significant fluctuations in power coming from large central plants. Such fluctuations can overly stress assets such as switching equipment and capacitors. Widely distributed generation would be less vulnerable and would also have the advantage of being local to the consumer, avoiding long transmission distances. Technology advances are needed in the inverters that would be used in widely distributed photovolataic generation to allow them to interact properly with the Smart Grid. Such developments, however, would be a boon to the semiconductor and embedded computer vendors who would supply the technology.
Another function that is foreseen for the Smart Grid and which also offers opportunities for second-tier vendors is demand response (DR) and its more advanced version, automated demand response (ADR). Current DR operations usually involve large consumers such as industrial facilities or college campuses where curtailing some percentage of consumption can free up power for use elsewhere during peak periods. Utilities often make such arrangements with large users involving agreements for them to limit predetermined points of power consumption in exchange for rate considerations.
ADR would expand such strategies by making them programmable and automated. Thus the utility and its customers could agree on levels of demand response that would be triggered by certain conditions with data and commands sent over the grid’s network. This could then be expanded to include commercial buildings that already have intelligent building management systems for controlling HVAC systems, lighting and security. The utility’s ADR application would then communicate with the building management software and implement the ADR operations, thus bringing demand response to a finer granularity over a larger number of consumers. Eventually ADR can be expanded into the home to the point of being able to turn down a thermostat by a few degrees or turn down an air conditioner. Such small adjustments over a wide number of consumers can amount to very significant power savings with little adverse effect on individual users. Additionally, for the home market, setting up the parameters for ADR would be in the hands of the consumer. Home users will be able to manage their home networked smart appliance by way of a display on their PC, a dedicated panel, via a tablet or smartphone (Figure 2).
Consumers get the best smart grid understanding when they combine smart appliances with a central reporting device. Users can see and adjust energy consumption data for each appliance—and understand how their household energy use burdens the grid. They can then make decisions about programming for such things as time-of-day pricing or ADR. (Courtesy of Altia)
An adjunct to this sort of demand response savings will be the advent of intelligent appliances that will connect to the grid network via the in-home wireless network (predominantly ZigBee) over the smart meter. Such appliances as washers, driers, dishwashers, etc., will be fitted with intelligent network-enabled modules to allow them to take advantage of time-of-day pricing and perhaps also ADR. Some appliance manufacturers will undoubtedly have digital design expertise in house, while others will be OEM customers of prebuilt modules. In any event, it is an opportunity both for the semiconductor as well as the modular board industry.
In addition to the ADR access to managed facilities, there are opportunities for third-party vendors to supply Cloud services for the management of multiple, geographically separated buildings from a central command center, or anywhere on the Internet. Data is exchanged and managed on a server in the Cloud and accessed over secure links by the management personnel with rich graphical interfaces.
Like renewable power generation, there will be other technologies that may be developing independently but will inevitably have to adapt to and be accommodated by the Smart Grid. Primary among these is the electric vehicle (EV). The development of EVs is gaining momentum and in various parts of the world their popularity is also rapidly growing. The advent of the Chevy Volt, the Nissan Leaf, the pluggable Prius and the move by Tesla Motors to develop an affordable sedan all point to the increased presence of EVs in significant if not universal numbers. This will have a big effect on the way the Smart Grid is designed and managed.
One of the major issues is the build-out of a public charging infrastructure. It is not enough to simply install charging stations in public places. There must also be a networking scheme to identify EVs connected to chargers so that the owners can be billed for the energy usage. Until there is a sufficiently large public infrastructure, owners will experience “range anxiety,” the uncertainty about how far they can drive and still get home or to a public charger.
Ideally, an EV should be able to connect to a charging station and have its ID read automatically so that the owner can be properly charged for charging his car. Although there is now a standard for connectors, there is as yet no standard network protocol for communication between the vehicle and the electric utility. Although there are a number of schemes out there, vendor-specific protocols will not work across utilities, so some sort of standardization effort is needed. The question arises as to who will build and maintain such a charging infrastructure. Will it be the utilities, municipalities or some third-party service company or companies?
There are also plans to take advantage of EVs to help stabilize the grid given the nature of the growing renewable resources. Since most cars, while used for basic transportation, are parked during the day after having been driven a fairly modest distance to work, they can be used to supply power to the grid during peak demand hours and then fully charge when they are parked at home at night. Just how this will all be worked out in terms of options for vehicle owners in a way that can also be standardized has yet to be determined. Still, it is not difficult to envision the heavy use of embedded computer intelligence in EVs, their charging stations and the network infrastructure. In addition, whether or not that infrastructure is a part of the Smart Grid, it will certainly have to communicate with the grid’s intelligent networking as well.
The advent of the Smart Grid has arisen out of necessity. We simply need to upgrade the national electrical power infrastructure. In doing so, however, we are creating a much richer environment. This environment will make possible even more creative ways to make the grid more flexible, safer, more robust and secure. However, it will also make possible the addition of ever more creative applications and services that will create new businesses and provide an even more connected world.