Distributed Energy Resources—What's on your grid today (and will be tomorrow)?

This blog was originally posted on LinkedIn.

Those in the electrical infrastructure industry would be hard pressed to have escaped the widespread consternation over the disruption that DERs are causing to utility business models and operations. Instead of transmitting and distributing power onto a grid that they own and control entirely, electric utility must adapt to prosumers both consuming, producing and storing energy via solar photovoltaics, wind, heat pumps, storage, EV, various types of controllable loads, and any combination thereof. Inversion of flows, altered voltage profiles, tighter balancing, lack of inertia, etc.—every single one of our long-established power system paradigms are now challenged.

Many voices and reports across the industry show that DERs are growing at a pace that most utilities are challenged to keep up with and can't control:

• Between 2011 and 2016, energy fed into the grid by consumers has grown on average at 500% per annum while net utility generation grew at 1.2%

• In 2017 the EU generated more than 30% of its electricity from renewable sources, up from 20% in 2010

• From 2018 to 2022, U.S. distributed solar installations are expected to double, from 2.0 million to almost 4 million

• A total of 99.1 GW of grid-connected solar was installed in Europe in 2017 — almost a 30% year-on-year growth over the 76.6 GW added in 2016

• Over 10 million three-person homes in Germany are powered by solar PV (photovoltaic) capacity

Ready to change? Where to start?

This unrelenting momentum for distributed generation means it's sure to play an ever increasingly and prominent role in our energy future. Undoubtedly, DERs offer the ability to:

• Facilitate sustainability
• Support energy independence
• Deliver cost savings to prosumers

But moving to successfully harnessing and managing DERs requires a bumpy journey for most electrical grid operators. Trials, pilots and demonstration projects of all kinds have flourished, demonstrating technologies, trialing new business models and regulation regimes, all working to pivot DERs from a threat to an opportunity.

So where to start? Lessons learned from front-runners lead us to consider the following as the first two stages:

1. Getting early visibility on the DERs—as they are currently connected and are continuing to connect to the grid today
2. Understanding how many more DERs can connect safely in the near future—hosting capacity analysis

Visibility: What is currently connected? What is connecting today?

Many utilities take the position that as long as DER penetration is marginal and they don't experience significant impacts on their energy flows and voltages profiles, they are safe and don’t need to be too concerned. Although understandable, such an approach may result in the utility waking up one day willing to tackle the challenge, and realizing that it allowed a significant number of DERs to connect without recording any information on what these resources are. These devices are not counted by the 100s, but rather by the 10s or 100s of thousands. And each and every one of them has specific characteristics. For example:

• What type of DER is it?
• What make/model?
• What is the capacity?
• What are its monitoring and control capabilities?
• Where is the grid connection point?
• Who is the owner?
• Who is the aggregator?
• Etc.

Setting up a clear and effective DER interconnection processes, whereby the utility is in the loop every time a DER is marketed and sold and commissioned on the grid, is essential to ensure that all of the data required to model monitor, and ultimately control these devices, is captured. Even if it's not critical today, access to all this data will be critical someday, and that someday will likely be sooner rather than later.

Hosting Capacity Analysis: How much more can we connect?

Assuming the utility now has a good grasp of what DERs are on its grid, it must then assess the current impacts. To what extent—and in which grid pockets—are the new particular grid patterns induced by DERs materializing today? Are there backfeeds somewhere? Are voltage excursions impacting quality-of-service? Are there tricky cold-load-pickup scenarios? Or are there wider balancing or stability issues at the Transmission level? Then, how many more DERs can the utility accept on its grid without major adverse impacts? This is the hosting capacity assessment, which looks to quantify:

• Existing queue
• Voltage constraints
• Thermal limits
• Power quality and reliability
• Protection and control
• Islanding/safety
• O&M

Further, utilities can start projecting into the future by modeling the development plans and predicted growth patterns of cities, neighborhoods, business parks, and shopping or entertainment districts. As Berkeley Lab research scientist Andrew Mills recently noted, “The rapidly rising penetrations of DER requires making distribution-system-planning decisions more quickly.” This means the utilities needs to move quickly now to start collating locational load and DER growth scenarios. Beyond “simply planning, in a deterministic manner, based on forecast loads,” the SEIA observed that utilities need to ultimately develop processes for guiding distributed energy resources to provide alternatives to traditional utility grid investment -but that's a bit far for a start.

As DERs surge into the power landscape, DER Orchestration becomes increasingly important with Visibility and Hosting Capacity as important first steps.

I invite you to learn more in our on-demand webinar: GE's End-to-end DER Orchestration: Visibility and Planning webinar.

In the meantime, read about GE’s position as a leader in DER Management in IDC’s DERMS MarketScape Report.