What's the deal with DERs?

As we’ve been digging into distribution and power supply topics, the phrase “distributed energy resources” (or DERs) keeps cropping up, and it doesn’t take much research to realize why this is such a hot topic.?

Distributed energy resources are small-scale power generators or storage systems located close to where the electricity tends to be used. Solar panels and small wind turbines are more common, but examples also include fuel cells, battery storage systems, and combined heating and power systems.

(Electric vehicles can be considered DERs, but only in certain contexts with vehicle-to-grid capabilities, like when EV batteries discharge energy back to the grid or use smart censoring to charge during off-peak hours.)

Generally, distributed energy resources are located “behind the meter,” meaning at homes or businesses (like rooftop solar panels), but they can also be found along feeders and occasionally at substations for really large installations.

Navigating New Tech within Traditional Distribution

Like most new power technologies, DERs are changing the power landscape quickly. Electric utilities are trying to adapt to include them in distribution systems, but integration has its own challenges.?

“Off” isn’t necessarily a synonym for “safe.”

Because DERs can operate independently from the grid, they can create safety concerns for utilities and first responders, especially in emergencies or routine maintenance. DERs can keep sections of the grid live while the rest of the system is down due to repairs or outages. Utility workers and first responders need to be aware of DERs and make sure they’re shut off before beginning work. Backfeeding situations can also be dangerous—if a DER sends power back through utility equipment that isn’t rated for bidirectional flow it can energize “dead” lines during outages.?

When planning distribution systems, engineers and utilities may have to take a different, more detailed approach to protection planning with updated safety protocols and detailed DER tracking.?

A touchy game of give and take.?

Not every DER stores energy (some simply generate it) and not everyone who owns a generation DER also has battery storage. When excess power isn’t used, it’s often distributed back through the grid using bidirectional flow.?

Traditional one-way distribution systems may need to be reevaluated and updated to handle backfeeding safely. Engineers will need to monitor equipment ratings and track flow from both directions for accurate modeling and planning.?

Location, location, location.?

The impact a DER has on the grid varies significantly based on where they’re found in the distribution system. Location affects things like system capacity, voltage, and grid support and protection. Applications and permits can help identify physical locations, especially when coupled with GIS. However, good asset management also needs data on electrical connection points and DER size and type.?

When planning or updating systems, utilities will need highly accurate data collection that includes detailed location and specs. However, keeping accurate records of all DERs can be challenging, especially with more installations and smaller resources going unreported.?

Modernizing maintenance and monitoring.?

Transformers and capacitors help maintain voltage and control load flow across the grid, but distributed energy resources can cause voltage to fluctuate based on generation.?

The grid may need to include advanced monitoring and control systems and utilities will likely need more granular and detailed data about equipment conditions and performance to plan for maintenance. Many supervisory control and data acquisition (SCADA) systems focus on large-scale equipment, but that might have to include data gathering from smaller DER systems.?

The winds are changing (and that makes it really hard to anticipate power flow).?

DERs add a new level of variables to load forecasting, making it even more difficult to anticipate user demands. Because many DERs are dependent on the environment, power generation changes based on weather patterns. A windy day could generate more power, but how much more? What will usage look like in the middle of storms??

Utilities need advanced forecasting tools to assess demand, and engineering firms have to account for variability when designing distribution systems to make sure that an especially sunny day won’t create complications in energy flow. More detailed data about DER performance and impact on the grid will help smooth out the challenges.

Positives of Power?

While DERs take some work to get right, including them in distribution systems can actually benefit utilities:?

• DERs can help lower the impact of outages by providing localized generation and storage. (Utilities just need to know where DERs are in these situations.)?
• By providing alternate sources of power during peak hours, utilities can use DERs to manage load more effectively.?
• Utilities can strategically place DERs themselves to help relieve over-congested areas with high demands.?
• As power companies look for renewable options, DERs can bridge the gap from other power sources so utilities can meet regulations and prioritize clean energy.?

Data Demands for DERs?

Data continues to be a consistent need when approaching DER integration. Over the next few years, DER adoption is expected to rise, nearly doubling in capacity by 2027. In preparation and response, utilities want to know where distributed energy resources are, what their operations are like, and how they affect consumption, generation, current, load, and more. More accurate, more detailed data collection is crucial to safely add DERs to current distribution systems.?

Thanks for reading! As we leverage Katapult Pro for distribution projects, we’re looking for ways to meet new data demands within the power industry. For more info on Katapult Pro for distribution data collection, engineering design, or workflow management, give us a shout at [email protected]!??