How fast is fast? Power monitoring and real-time response rates

My first car was classic Mopar: a green ‘68 Dodge Dart GTS. I bought it from my uncle who owned a local mechanic shop and did a lot of custom engine work. When I asked him about engine mods, he paraphrased a quote from Mad Max: “speed’s just a question of money, sonny… how fast you wanna go?” I was seventeen; I would’ve spent the equivalent of the gross national product on that car. A little power was good; more power was even better. Thankfully my older, wiser uncle talked some sense into me before I got into serious trouble.

Communication speed

Now that I’m (a little) older, I can see the question my uncle wanted me to consider was how fast do you really need to go? Aside from classic cars, I’ve been thinking about how this question also applies to the speed of power monitoring systems. How fast should they be? For the sake of this discussion, let’s put the system in a data center, and let’s define speed as the power system’s operational deadline, from event to system response. Ultimately, the major factor when it comes to this kind of speed is the communications system; for example, UI update rates depend on how often the monitoring software polls a device, the number of devices on a serial line and how quickly the device can receive, process and respond to the software requests. Today, a well-designed power monitoring system designed for data center applications can provide a healthy screen update rate of four seconds and an alarm register update of three seconds or less. That’s pretty fast, and it’s really important in critical power applications like data centers where downtime means loss of data, significant financial losses, and damaged reputations.

But not every application is that critical and not every business needs power monitoring systems that fast. With the adoption of ISO 50001 energy management framework gaining pace around the world, a growing number of businesses are jumping on the power monitoring bandwagon and seeing great results. Occasionally, however, we see companies asking for higher-speed specs typical of SCADA systems (supervisory control and data acquisition software) for their power monitoring systems requirements. SCADA systems also refresh at incredible speeds, and are typically used in industrial and infrastructure environments where reducing outages and increasing power efficiency is critical. But there’s nothing in SCADA systems’ telemetry or protocol that limits it to utilities, mining, or gas and oil industries. And hence the question: how fast do we need to go? Is an extra-fast system – with its associated cost – really worth it for power monitoring applications? What are you going to do in that one or two second difference?

Worth the investment?

As I mentioned, the time required to have your data on your display is completely dependent on your network. Bandwidth, topology, data transmission rates, device processing time, and the number of devices in the network all affect the speed of communication. And while today’s routers and switches are capable of 1Gbit/s speeds – providing more than enough bandwidth for a power monitoring and control network –  serial devices are considerably slower than Ethernet-connected devices. Upgrading for speed can mean significant and expensive device upgrades. Is it really worth a possible six-figure price tag?

A straightforward solution is a well-designed power monitoring architecture that gives reasonable response. Logged, time-stamped values will expose power waste, unused capacity, and historical trends, all without the need for ultra-fast response rates. Plus, monitoring software allows you to track power conditions and remotely monitoring of electrical equipment or installations at key distribution points.

Obviously, companies need to have honest conversations with themselves to determine what kind of power monitoring solution works best for them, and from which applications will they benefit most. The answer most likely lies in answering the brainteaser: time is money; how fast do you want to go? Just like my classic Dodge, the best decision usually involves a lot of wisdom.

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