How Smart is the Grid?


Marketing and advertising groups often have a tendency to capitalize on technological trends faster than engineers and users can settle into the technology itself. Perhaps it’s no surprise that it is difficult to hold back the motivation to get a product to market and profit. Right now the most glaring example is the practice of carelessly putting WiFi in appliances and toys and putting them on the Internet of Things, but there is a similar type of fiasco playing out in the electric power industry as well. Known as the “smart grid”, an effort is underway to modernize the electric power grid in much the same way that the Internet of Things seeks to modernize household appliances, but to much greater and immediate benefit.


A Cutler-Hammer industrial breaker ominously predicts the coming confusion in the smart grid arena.
Photo by Bryan Cockfield

To that end, if there’s anything in need of modernization it’s the electric grid. Often still extensively using technology that was pioneered in the 1800s like synchronous generators and transformers (not to mention metering and billing techniques that were perfected before the invention of the transistor), there is a lot of opportunity to add oversight and connectivity to almost every part of the grid from the power plant to the customer. Additionally, most modern grids are aging rapidly at the same time that we are asking them to carry more and more electricity. Modernization can also help the aging infrastructure become more efficient at delivering energy.

While the term “smart grid” is as nebulous and as ill-defined as “Internet of Things” (even the US Government’s definition is muddied and vague), the smart grid actually has a unifying purpose behind it and, so far, has been an extremely useful way to bring needed improvements to the power grid despite the lack of a cohesive definition. While there’s no single thing that suddenly transforms a grid into a smart grid, there are a lot of things going on at once that each improve the grid’s performance and status reporting ability.

Supervisory Control and Data Acquisition (SCADA)

The most widely used grid control system is known as Supervisory Control and Data Acquisition, or SCADA. This is an industry-standard across a wide range of technologies which has been adapted for use on the grid. This allows power system operators to see which breakers are open or closed, which generators are online, what the voltages are at various points, where problems in distribution lines might be, etc. It allows dispatchers to get a high-level view of the grid and to take some control over how power flows through it. Newer implementations and additions to this system allow the grid to detect faults more quickly and divert power flow around the fault, if possible, which is a key feature of a modern smart grid.

While SCADA is a powerful tool for system operators and dispatchers, it can be lacking in some areas that have been most impacted by modern technology. Certainly, a grid equipped with only a SCADA system is not considered a smart grid. Specifically, it lacks control of anything going on “behind the meter”, or within a customer’s control, which is where a lot of emerging smart technologies are focused. This includes handling electric car charging, active management of power-hungry appliances like water heaters and air conditioners during times of peak demand, and microgeneration like rooftop solar.

Smart Metering

Besides these specific new technologies, another major part of the smart grid has already been widely implemented: the use of smart meters. These are electronic (rather than electromechanical) meters that can report energy use remotely, eliminating the need for a meter reader. It also allows for demand-rate metering and other innovative ways of billing at particular times of day and for different uses which older style meters cannot do. Unfortunately, despite all of these advantages, these particular devices are often in the news because an extremely small minority of people have become convinced that the non-ionizing radio waves that the smart meters use are somehow harmful, despite absolutely no evidence to support their claims, and despite the fact that these frequencies see extensive use already.

Absorbing Blips with Battery Banks

Another important improvement that the smart grid brings to the table is the ability to easily handle energy storage. While battery technology is notoriously behind schedule, it’s currently not economically viable to have large-scale batteries on the grid to store energy for longer than a few hours.

Most battery banks that are online perform a task called “load balancing” where short-term (in the range of seconds to minutes) supply and demand is balanced. For example, starting up an industrial facility like a saw mill may put a brief high demand on the local grid, which can be balanced by a battery bank almost instantaneously in order to mitigate a voltage sag. On the other hand, a sudden load loss on the grid can be absorbed by charging the battery bank which maintains grid stability in the other direction.

Perhaps in the future battery technology will be mainstream enough to absorb daily cycles of demand from something like a solar site, but the price point and technology are not quite where they need to be for widespread adoption of something on that scale. Flow batteries are a decent alternative to lithium-ion batteries for this type of application, but need to be improved upon before large-scale adoption.

Microgeneration

Like battery banks, microgeneration can be used to help the smart grid as well. Microgeneration refers to small power generation like rooftop solar or small methane generators at landfills. A sufficiently smart grid has more ability to know when these distributed generation facilities are online, and can use this information to maintain grid operation in a more efficient way than would otherwise be possible.

With all of its benefits, however, the smart grid doesn’t have a clear standard yet. Like the Internet of Things, it sometimes seems like a lawless technological free-for-all. There is often not even agreement between power companies that operate in the same state or country as to how they should handle and implement these emerging technologies. What the industry needs is a clear standard to rally behind, but it doesn’t seem like anything will be filling that void anytime soon.



Source link

Leave a Reply

Your email address will not be published. Required fields are marked *