The Smart Grid is a collection of technologies, all communicating and interacting with each other, grid operators, producers, and consumers. Utilizing the existing infrastructure and adding functionality to it, the overall feature set of Smart Grids is significantly greater than the sum of its component parts as, with every new individual technology integrated into the whole, new synergistic benefits develop. While these benefits are what the Smart Grid actually offers, it is prudent to first look at the major components of Smart Grids before delving into how they interact with one another.
Metering technology is the foundation upon which Smart Grids function. Smart meters measure and analyze electricity usage, constantly communicate the data they collect to central locations, and, differentiating them from past technologies, are capable of two-way communication with the grid as a whole, influencing and being influenced by other components in the Smart Grid. Advanced Metering Infrastructure, AMI, is the networking of devices and protocols that allows for this two-way communication, representing the collective advances in metering and communications technologies.
One immediate result of this improvement in metering is the potential for a shift away from flat-rate fees for electricity in favor of time-of-use pricing, where the cost of using electricity reflects the cost of producing that electricity at that very moment, financially incentivizing the voluntary shifting of demand away from peak hours, and, due to the nuances of how electricity is generated, making the grid as a whole more efficient and stable as well as lowering the overall cost of electricity for everybody.
Furthermore, the information provided by constant and automated metering is of great value to both customers and utilities. Customers see their electrical usage in more detail than before, as well as the current price of electricity, giving them greater awareness of and control over how, when, and at what price they use electricity. Utilities and grid operators benefit from the constant flow of information from automated metering through reduced operating costs, improved customer service (and therefore satisfaction), immediate identification of trouble spots, more accurate predictions of grid conditions in the future, and more informed planning for further infrastructural improvements. Appropriately, the benefits gained by utilities go on to positively affect customers.
Demand Response and Dynamic Demand are a group of technologies reacting to the overall balance of supply and demand in an electrical grid by utilizing the features of individual devices to adjust both supply and demand to a more optimal balance. Reacting to PMUs sensing the grid’s electrical frequency or signals from the grid passed through the AMI, Demand Response technologies alter the functioning of compliant devices to reduce or reschedule demand, increase supply, or even increase demand, depending on the grid’s needs at any given moment, serving to stabilize the grid and reduce the likelihood of service disruptions or equipment damage, as well as both decreasing costs and increasing efficiency.
One example of these technologies is light dimming, with new ballasts capable of automatically reducing the brightness of fluorescent lights by an acceptable percentage in response to either a request from the grid or a financial incentive. While the consumption of each individual light is miniscule, the cumulative demand of lighting systems in a city represents more than enough demand to warrant serious attention. Similarly, the electrical usage of many home appliances can be slightly reduced for short periods without any adverse effects on their functioning, all the while, in unison, representing a significant reduction in demand on the electrical grid. Cooling and heating systems are especially applicable here.
In general, the ability to reduce demand by a certain amount is as useful as the ability to increase supply by that same amount in terms of stability, with the added benefit of reducing costs and infrastructural requirements.
Smart Grids include a series of features designed to improve stability and mitigate the effects of unavoidable damage. As mentioned, Demand Response seeks to balance demand and supply across the grid. However, what Demand Response addresses is not the only concern of grid operators, as potential problems range from downed trees, unexpected failures at power plants, or even attacks by malevolent parties.
The extensive metering network can identify problematic conditions before any service disruption or equipment damage occurs, act accordingly, and prevent issues that today would need independent resolutions. This ranges from pattern recognition, the nuanced identification of grid conditions that are known to precede problems, combined with preemptive solutions, to immediate damage control, such as the sectioning off of damaged areas to prevent the spread of damage.
While the responses mentioned so far have all been either remote or automatic, not everything can be done remotely, e.g., the Smart Grid can’t remove a fallen tree from a power line. The information provided by the Smart Grid also illuminates those problems that can only be resolved by dispatching repairmen, both reducing the time delay between the occurrence of a problem and when the repairmen know about it and providing them with more information before they arrive at the scene.
This way, whether the problem is a surge in demand, a fallen tree, a power plant failure, or an attack, the Smart Grid can mitigate or even completely eliminate service disruptions or (additional) equipment damage.
Security and Standards
Recognizing that improperly designed Smart Grids are vulnerable security risks, the involved industries have collaborated to assemble a large collection of standards, detailing secure protocols, mechanisms, and procedures for equipment interconnecting distributed resources with electric power systems, communication networks and systems in substations, power system management and the associated information exchange, distributed networks, intelligent electronic devices, advanced metering infrastructure, as well as the integration and upgrading of relevant existing standards, such as those developed by the North American Electric Reliability Corporation (NERC) or those for home area networks. Standards also carry the role of promoting interoperability, assuring that not only will Smart Grid components be resistant against unauthorized access, but that they will readily connect with those devices with whom they are supposed to interface with in order to function properly. NIST, the National Institute of Standards and Technology, is one of the driving forces behind standards development with its Smart Grid Interoperability Panel. NIST also releases drafts of the NIST Framework 2.0, encouraging public feedback and allowing everybody to contribute to the resulting set of standards.
As one example of collaboration, two standards developing organizations, ASHRAE, the American Society for Heating, Refrigeration, and Air-Conditioning Engineers, and NEMA, the National Electrical Manufacturers Association (both accredited by and members of ANSI, the American National Standards Institute), work together to develop the Facility Smart Grid Information Model, which “define[s] an object-oriented information model to enable appliances and control systems in homes, buildings, and industrial facilities to manage electrical loads and generation sources in response to communication with a “smart” electrical grid and communicate information about those electrical loads to utility and other electrical service providers.”
As one of the biggest obstacles to overcome when developing and installing a Smart Grid is sorting out the standards necessary for security, interoperability, and functionality, the current level of cooperation is an important step in the right direction.
Another feature of the Smart Grid is its capacity for the integration of a wide variety of technologies that can’t or aren’t being fully utilized at the moment. Largest in apparent scale among these are intermittent energy sources, with the Smart Grid’s ability to influence the demand of electricity within the grid allowing greater penetration of power generation utilizing wind or solar. Distributed, small-scale sources of energy connected to the grid can collectively function as a virtual reserve power plant. Additionally, the use of geographically distributed wind and solar power sources can smooth out the variability that large-scale wind and solar farms are normally subject to. Energy storage can also be drawn from to bolster the virtual reserve provided by small scale electrical generation, drawing electricity during periods of low demand and returning it back to the grid during periods of high demand.
The Smart Grid also cooperates with new and currently emerging technologies. In many cases, the standards guiding the Smart Grid were designed with future upgradeability as a requirement, providing the framework for integration with new technologies. Electric cars are one example of an emerging technology. They, like any other cars, spend a lot of their time parked. However, unlike today’s gasoline-driven cars, electric cars have batteries that can be made to function as a vast distributed network of electrical storage.
Rather than merely serving as the distribution network between power plants and consumers, Smart Grids transform the electrical grid into an active participant. In terms of developing infrastructure, the Smart Grid’s features reduce the need for the construction and maintenance of additional power plants, transmission lines, etc…, eliminating both the immediate expenses as well as having to find and secure the necessary land. In terms of existing infrastructure, Smart Grids squeeze more functionality out of what already exists. Themselves a collection of advances, Smart Grids provide the framework necessary for further advancement, bringing our infrastructure more in line with what it can potentially be.
Click to see an ANSI press release discussing recent developments in the Smart Grid standardization effort.
This is the third article in a series about Smart Grids, each of which can be read independently.
The first article is an introduction to the concept of a Smart Grid.
The second article explains the generation of electricity.
The fourth article delves into Demand Response and its economic effects.
Also, a previously published and updated list of standards for Smart Grid Interoperability.