What You Should Know About the Smart Grid
What is the “Smart Grid” and why is it getting so much attention? This is the first in a series of articles that will examine Smart Grid issues and Milsoft’s Smart Grid software solutions. This first installment will cover some foundational concepts and principles. These include:
- What is a grid?
- Is the grid smart?
The next installment will describe why a Smart Grid is necessary. The following installment will describe the characteristics of a Smart Grid and how it can be achieved.
For starters, what is a “grid?” It is a system of electrical generators connected by transmission and distribution lines and equipment to devices that consume electricity. The purpose of the grid is to supply consumers’ enough power and energy to meet consumers’ demands with acceptable economy, reliability and quality. All of the generators, transmission and distribution lines and energy consumption devices in the United States are often referred to as “the grid” although there is actually a collection of some 3,000 plus smaller grids connected together. In some cases the interconnections between and among the smaller grids are numerous and robust. In others the interconnections are few and weak. In every case, however, as further explained below, the grid is fixed, not fluid; ponderous, not agile; reactive, not pro-active; pre-programmed, not adaptable. The grid is not smart.
Electric utilities have historically tried to achieve acceptable reliability and quality of service by planning and constructing an adequate amount of generation, transmission and distribution to meet consumers’ peak demand plus enough surplus capacity and redundancy to accommodate short term growth customer demand and recover from unplanned outages and other system disturbances. To achieve economies of scale, generation and transmission are concentrated. That is, very large generation plants are built in locations remote from load centers and transmitted through largely radial bulk transmission (collectively, the bulk power system) to service many customers dispersed throughout the grid. The grid is made up of very large assets whose locations, capacity, and operating characteristics are largely fixed.
Once the grid is constructed, there are few options to significantly adjust operations to achieve system efficiencies or other goals. It is not adaptable to dramatic changes in circumstances (e.g., the need to switch from one fuel source to another or to operate with a significant portion of the bulk power generation and transmission assets out of service). Nor is the grid readily controllable in the short term outside of the bounding constraints of the fixed location, capacity and operating characteristics. The only real option that utilities have to significantly address persistent or profound problems (e.g., declining reliability or quality of service, fuel supply disruptions, changes in consumer behavior, new environmental constraints) is to invest in more or different large fixed assets. This has obvious adverse implications for the economy of service.
It is true that the grid is able to respond quickly to changes in consumer demand (i.e., load dispatch) but only as long as it is there is sufficient existing capacity in the bulk power system and it doesn’t change much in its geographic distribution, and as long as the bulk power system can support the alternative power flows. The grid can quickly vary production among available generators based upon short term changes in fuel availability and price (economic dispatch) but only to the extent that surplus generating capacity exists to take advantage of a different fuel and adequate transmission capacity exists for the alternate route. The grid can quickly take generators, lines and equipment out of service if there is a danger being overloaded to the point of irreparable damage but with potential adverse implications for reliability of service.
As if this were not enough, consumers cannot interact intelligently with the grid. Electric utilizes have historically communicated the costs of providing acceptable availability, reliability, and quality of service via long term average pricing rather than reflecting the reality that the magnitude of costs vary widely in the short term. And utilities measure consumers’ purchases through long term macro indicators (i.e., monthly demand and energy readings) rather than in a way that would allow for short term price signals to match short term changes in consumption. Both the means of measurement and the method of pricing are complex, even arcane, and not well understood by consumers. A consumer who wishes to reduce the monthly cost of power cannot readily tell how to do so. There is no information at all on other matters of interest to the consumer such as the sources and kinds of fuel being used to meet the consumer’s needs, or the environmental impacts or carbon footprint resulting from meeting the consumer’s needs, or the short or long term effects for the consumer or the utility or the community resulting from changes in the magnitude or characteristics of the consumption.
So, not only is the grid not intelligent, it is mute. As a result, the consumer cannot be smart, either.
(Next time: So why does the grid need to be smart?)
Written by Steve Collier | Jun 14, 2009