Perhaps you’ve seen commercials like GE’s “If I only had a Brain”, but what does SmartGrid really mean? And more importantly, what does it mean for the average citizen? To answer these questions for myself, I spent last week in Washington, DC attending the SmartGrid conference. I was probably the only nuclear energy consultant in the room, but I believe that understanding the issues facing the industry in this arena are key to my industry’s ability to succeed.
So What is SmartGrid? In the simplest terms, it is a broad set of initiatives around electric power delivery from generation to end-user. It breaks down into roughly 4 areas to consider: Generation, Transmission, Distribution, and Consumption.
We, as consumers, can see and feel that last portion, and that is certainly the area that has received the most attention. However, in reality, we should care about and pay attention to what is happening with the other three. These areas will have far greater impact on the availability, reliability, and stability of electricity to power our lives. What’s this? Clean, reliable electricity? Don’t we already have that?
Well, in a word, NO.
The electricity system in the US is incredibly complex. Most of us have little appreciation for shat it takes to deliver electricity to that plug in the wall. The system is essentially on demand. There is virtually no storage of energy, and yet balance is maintained. As electricity is demanded, it is created, transported and delivered to the consumer.
The fact that large swings in demand do not cause blackouts, brownouts, or fried equipment on a regular basis is an engineering marvel that is one of the major technical achievements of the 20th century. That fact that it is done with technology little changed since the 19th century is miraculous.
The initiative known as SmartGrid is probably going to impact our country almost as much as the original electrification efforts of the early 20th century. Ironically, if it succeeds, most of us will perceive little change to their daily relationship with electricity. Plug in an appliance and electricity will flow. BUT, these changes will ensure that flow is reliable, clean and safe. AND that the new plug-in electric vehicle in the garage is ready to go whenever and where ever the proud new owner chooses to take it. The air will be a little cleaner, and no warmer than it was at the start of this project.
If the initiative fails at its objectives, however, the outlook is much more bleak out at the edge of the grid. The choices in this country will be painful and expensive. The potential negative impacts on the environment and the economy are enormous and our children will face a future with fewer options.
So, SmartGrid must succeed. Succeed at what though? Briefly, here are the four areas and their issues.
The demand basis upon which we operate and the societal desire to move to more sustainable generation options make managing the generation of electiricy expremely complex. Today, the energy mix in this country is primarily coal, nuclear, and hydro (when its available) for baseload demand. Natural gas is used to handle the variable demand. Solar, wind, and other alternate energy options make up a very small percent of the total available electricity generation. However, in markets where as little as 4% of generation comes from wind, the inherent volatility can already have major impacts on both the volatility of energy pricing as well as total supply available on the grid.
The current ability of the grid to add and shed the electrical demand is too slow and too limited to handle more than a few % of these volatile energy sources. Today, in markets where significant wind or solar generation is a part of the mix, the utility must also maintain significant fossil generation (usually natural gas) spinning in reserve to back-up the supply. This back up power is idling like your car, burning fuel, but not actually going anywhere so that it is immediately available should clouds pass between sun and solar panels, or the wind change speed. On average, it requires the utility to run about 85% of the load in reserve. This means that the goal of reducing emissions is almost completely missed.
In utility speak, the phrase T&D commonly crops up and refers to transmission and distribution. An analogy related to our road system helps to understand how they relate. Transmission can be thought of as the insterstate highway system where large numbers of vehicles are moving at high rates of speed over long distances. In electricity, these are those huge high voltage lines that stretch into the distance between big power stations and the population centers. Distribution is the local road system. It delivers electricity from the neighborhood substation to each house.
Those high voltage lines that crisscross the landscape and the huge switch yards outside the power plants are the primary components. In order to allow regions to be isolated, there is minimal interface of these transmission lines from one region of the country to another. This was a conscious decision on the part of the original designers of the grid system to prevent failures in one region from propagating further. The transmision system include DC and AC current as well as transformers and capacitor banks to step voltage up or down as required.
Currently, there are few sensors or communications from the large switchyards with one another or with a central authority. Thus, problems can develop over the course of time. These issues can cause huge cascading effects that darken entire regions of the country. In addition, there is very limited sensing data associated with the high voltage lines. An issue at a single tower can require significant resources to track down and repair.
The local switchyard manages the step down of voltage from those high voltage lines to a level that is safe to distribute into a neighborhood where additional pole based transformers and capacitors manage the remaining voltage and demand control into each building.
Most utilities cannot determine where a fault occurs and must wait for consumers to contact them regarding outages to find and correct issues with the power supply.
Ultimately, all of this infrastructure exists to get power to the end-user. The consumers break down into roughly three types: commercial, industrial, and residential. This is where significant variation in usage creates huge spikes in demand. The most notable development was that of air conditioning. As air conditioning has become common, electricity demand spikes on hot summer days have continued to soar. Addition of electronic gadgets of every nature, big refrigerators and freezers, and hot water heaters have increased baseload demand as well.
The final twist is that of consumers as producers. Increasingly, consumers of all types are looking at the possibility of generating electricity. Allowing excess electricity to flow back into the grid from the edge requires some fundamental changes to the way the systems are designed to operate.
Over the next few articles, I’ll explore each of these areas in more detail.