Distributed Grid Management 101: DERs are reshaping the power grid

DER technologies have rapidly sprung up in recent years and continue to mature

It’s no secret to the general public that the power grid, and the power industry behind it, are undergoing the greatest transformation since its inception well over a century ago. Much of the change has been driven this decade by the rise of distributed energy resources (DERs).

DER technologies have rapidly sprung up in recent years and continue to mature – technologies such as distributed generation (e.g., solar PV and wind), demand response, electric vehicle fast chargers (not only cars but the electrification of buses, rail, ports and fleets), energy storage (BESS, mechanical storage like flywheels, and thermal storage), microgrids (which facilitate renewable generation, storage and grid resiliency), energy efficiency, and virtual power plants.

These resources all connect to the grid at the distribution level. And as the penetration of DERs increase, the distribution network changes from a single-source radial network to a multi-source grid, meaning utilities must maintain voltage limits, watch for short circuit interruption limits and maintain the interconnected network’s stability, as DERs make the whole process more complex and challenging.

While DER deployments still account for only a small fraction of installed generation capacity, they are growing fast, and their potential is undeniable, presenting both opportunities and challenges.

On the positive side, there are many benefits, such as reduced environmental impact, deferred capacity upgrades, optimized distribution operations, lower emissions, grid flexibility, expanded demand response capabilities, optimized distribution operations, improved power system resiliency, and customer choice, since in some cases DERs are located behind the meter such as rooftop solar. Managing load at the grid edge to match the generation characteristics of renewable generation presents huge opportunities.

Microgrids, both in front of and behind the meter, have seen rapid growth and can better manage storage, wind, solar and thermal generation while maintaining grid stability, running on 100 percent renewable energy with storage as the grid-forming device. Grid edge control technologies for CHP, grid supply, and onsite generation enable optimized virtual power plants and C&I sites.

Energy Storage has likewise grown and gained widespread acceptance. The US storage market will grow 17 times from 2017-2023 and will approach the 1 GW threshold in 2019 or 2020. This is also the year when California will require solar for all new homes, which has upside for residential storage.

On the challenges side, DERs represent a vexing challenge for utilities, like keeping their promise to provide safe, reliable, and affordable power to their customers despite the introduction of thousands of new supply resources, bi-directional power flows and greater variability. DERs are also driving a tectonic shift in the industry’s very structure.  These challenges mean that utilities must operate the grid in a much more agile manner. Fortunately, there are now ways to monitor and control assets, such as SCADA, Distributed Energy Resource Management Systems (DERMS) and other enterprise systems allowing DERs to realize their full potential, maximizing returns for asset owners and optimizing operations for utilities.

Another related challenge (and opportunity) involves renewable energy penetration and integration onto the grid. As many states inch toward meeting their respective Renewable Portfolio Standards, and others take steps toward a 100 percent wind and solar future, utilities must deal with obstacles such as transmission access, congestion at the transmission level, and generation base load and ramping requirements. As renewable penetration reaches 50 percent, the headwinds increase, and many experts acknowledge that transmission investment will be needed to relieve this congestion and add grid flexibility.

Finally, there are environmental and societal trends that the industry cannot fully control. 2017 was a record year for the most $1 billion+ weather events and “500-year storms” (and 2018 was not far behind), leading to larger regional outages and added stress to the grid. These storms did help raise social media as a valuable tool for utilities to provide valuable information for their customers and operations. Pathways to reduced greenhouse gas emissions will include goals for renewable generation and electrification of transportation.

Despite these challenges, there is no turning back as distributed energy resources continue to grow rapidly worldwide. But DER technology – like the ones mentioned above as well as advancements in systems like DERMS and Advanced Distribution Management Systems (ADMS) – continues to mature and become more commercially acceptable, thus improving grid reliability, economics and operational efficiency.

To learn more about the impact of DERs on power grids, watch a webinar on demand, Distributed Grid Management 101, that I presented recently. The webinar will provide additional details on how aggregated DERs impact transmission and centralized generation operations, what regulatory mandates are in place today and what we can expect in the future for distribution grid management.  This webinar is part of a 2018 PowerEd digital grid webinar series presented by ABB.

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About the author

Gary Rackliffe

Hello, I lead Smart Grid Development for ABB North America. I have more than 25 years of industry experience in both transmission and distribution (T&D) and have worked with ABB for 19 years across a variety of positions. I hold a bachelor’s and master’s degree in electric power engineering from Rensselaer Polytechnic Institute and an MBA degree from Carnegie Mellon University.
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