Generac Grid Services Blog

DERMS: Coming Soon to Your Utility’s IT/OT Convergence

Posted by Malcolm Metcalfe on Sep 8, 2016 11:38:22 AM
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Last year, analysts at Gartner placed IT/OT convergence on their Top-10 list of trends affecting the utilities industry. Actually, it’s been in progress for nearly a decade but, now more than ever, IT/OT integration looms as a crucial utility move. What’s more, it is factors outside utility walls that are rousing such urgency. What are they? Look around your neighborhood. If you see a lot of rooftop solar panels, some of those factors are sitting right in front of you.

What’s more, GTM Research forecasts a 94 percent increase in new PV installations in the U.S. during 2016. Worldwide, Navigant Research says, “Annual installed capacity across the global distributed energy resource (DER) market is expected to grow from 136.4 GW in 2015 to 530.7 GW in 2024, representing $1.9 trillion in cumulative investment over the next 10 years." 

What does this have to do with IT/OT convergence?

The more generation on your distribution system that you don’t control, the more you need to find some way to control at least some aspect of that generation. That’s where a distributed energy resources management system (DERMS) comes in. It’s the software that manages those generation devices that aren’t on the utility’s side of the meter. And, as DERs proliferate, DERMS iStock-958125956will become increasingly crucial.

Making the most of co-generation

To understand why DERMS are now so important, let’s look at one impact of co-generation from rooftop PV: voltage excursions. Right now, the most commonly used interconnection standard is IEEE’s 1547, which is under revision but currently requires solar PV to shut down when utility generation goes down or there’s a problem on the distribution system.  If there’s no voltage on the grid side, there can be no voltage on the customer side.

But not all of the power produced by a solar installation necessarily goes to power customer equipment or come back to the utility. A percentage of that PV power goes to consumption or production of volt amperes reactive or VARS, the power that controls voltage. The percentage is negotiated with the utility as part of the connection agreement.

Right now, that percentage of inverter capacity providing voltage support doesn’t change, because when people use non-smart inverters – or inverters with no communications and computing power built in – that percentage must be a preprogrammed set point at which the PV installation’s inverter always outputs its VARS.

Here’s the problem with that preprogrammed set point: if you’re using the inverter for voltage support and you lose the solar array because of cloud cover, you also lose the voltage support. Now, all of your capacitor banks have to make up for that loss … if they can. And, even if you have enough cap bank support, it’s still a lot of wear and tear on some very expensive equipment.

With a distributed energy resource management system, set points on smart inverters can be dynamically controlled, along with the utility voltage control equipment on the line. The voltage at the inverter’s terminals can be measured, monitored and optimized centrally, resulting in better voltage for all customers and less loss, which is a factor that is currently billed to everyone. With the added DERMS control capabilities, the inverters can be allowed a larger window to ride through any momentary disturbances without exacerbating the disturbance.

That’s just one example of where a DERMS solution can help with more effective grid operation. Here’s another. With a DERMS, the flexibility of DERs can be used for renewable firming when cloud cover impedes solar generation connected to the grid.

For example, Enbala uses a collection of loads from nearly three dozen small- to medium-sized buildings with some 2,000 connected assets to provide renewable firming for New Brunswick Power, a utility in Canada’s Maritime provinces near the North Atlantic. Here, more than 30 percent of generation comes from renewables, and much of it comes from wind power, which has intermittency to factor in.

In NB Power’s renewables firming program, the DERs controlled by the DERMS platform include loads from retail facilities, warehouses, schools and several municipal water pumping stations. Together, these DERs give NB Power around 2.5 MW of flexibility on a continuous and dispatchable basis.

NB Power sends energy dispatch requests to the platform that call for a specified increase or decrease in net energy delivered over a set period of 15-minute intervals. The platform determines the optimal power consumption set point to send to each customer site, taking into account the real-time operating status of each device at each customer site, as well as the operating parameters that customers themselves define. That means the customers don’t sense any impact of this control because their systems continue to operate within tight constraints.

The platform aggregates responses from all the individual devices so that they appear as a single, dispatchable resource for NB Power. So, their target energy, which is generally something delivered by utility operations teams, winds up being provided by software. 


Such DERMS applications may not be what you think about with IT/OT convergence because so many write-ups focus on the how IT systems, like customer service or billing, will leverage OT systems, such as SCADA or advanced metering. But, just as the generation resources that power our grid are changing, so must the systems that keep energy in balance. For a DER-heavy grid, a DER management system is a great place to steer the IT/OT convergence in your organization.


Topics: distributed energy resources, Distributed energy resource management, Solar energy, DERs, renewable firming, smart inverters, DERMs, IT/OT, IT/OT Convergence, energy aggregation

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