Grid owners and operators manage electricity delivery over an extraordinarily wide range of time scales, from functions that require adjustments to grid conditions within microseconds to long-term planning for infrastructure investments with a decade or longer time horizon (Figure 1). The increasing penetration of both distributed and utility-scale renewable generation affects grid operations at all time scales and also adds an increasingly complex geographical component.
Figure 1. System operation depends on managing multiple event speeds. Source: U.S. DOE. Quadrennial Energy Review.
In September, the GridWise Alliance explored some of the implications of high penetrations of renewables on the grid. Flexibility across the entire power system, both physical and structural, will be key to integrating renewable energy. Discussions during the Policy and Technology Councils this month touched on different aspects of planning, and highlighted some flexibility resources that can address the short-, medium-, and long-term effects of renewable generation.
The Policy Council meeting featured two speakers. Heather Donaldson from Black & Veatch kicked off the meeting with a presentation on several distribution system operator (DSO) models which could be well suited to planning, operating, and compensating for DERs (Figure 2). Next Darren Murtaugh from Portland General electric shared insights from their dispatchable standby generation program, which started as a demonstration program and proved to be one of the most reliable resources for contingency reserves during the summer heat wave in the Pacific Northwest.
Figure 2. Local Utility as DSO with Distribution-Level Market –
Model 1 Variation Source: Black & Veatch. Presentation on
Distribution System Operator Overview. September 2021.
A full panel of speakers presented to the Technology Council. Robert Sparks and Khaled Abdul-Rahman from CAISO discussed planning analysis for transmission with projected renewable generation quantities and recent models developed by the ISO to evaluate storage and co-located resources. Ravi Pradhan and Wenchun Zhu from Siemens Digital Grid next spoke to share insights and challenges related to operating the grid with increased renewable generation. Figure 3 below illustrates current and future ways of integrating DERs into the grid.
Figure 3. Evolution of DER Integration on the Grid. Source: Siemens. Presentation on Operation and Evolving Technology with the Integration of Renewables. September 2021.
Be sure to check out our website for some of the resources members provided in response to our call for content this month. A few content highlights are noted below:
For more on studying the impacts of renewable energy growth in an ISO:
- Read this Renewable Integration Impact Assessment report from MISO.
- MISO conducted this detailed assessment to identify integration issues and evaluate potential solutions to mitigate them.
- This study also facilitated deeper conversation in the region about maintaining reliability with higher levels of renewables.
- Key findings are summarized by Figure 4.
Figure 4: Key findings from MISO’s Renewable Integration Impact Assessment
For more on integrating offshore wind to an onshore grid:
- Read this Offshore Wind Integration Study conducted by DNV (See Appendix D).
- Contracted by New York state, a team led by DNV worked to identify better-performing onshore substations to interconnect 9 GW of OSW into New York City and Long Island in a reliable and cost-effective manner; evaluate the environmental and permitting challenges associated with bringing the OSW power to selected onshore substations; and evaluate plausible offshore transmission solutions for collecting and delivering the remaining 7,175 MW of OSW that is not procured yet.For more on modernizing substations to better integrate cleaner energy resources and increased DERs:
- See this Infrastructure Modernization report from Intel
- Intel makes the case for modernizing and digitizing substation infrastructure, calling for standardized hardware platforms and the implementation of software-defined automation and control systems.
- Substations are an integral component of operating and managing the grid and commonly sit at the intersection of distribution and transmission networks, as illustrated in Figure 5.
Figure 5. Substation commonly sit at the intersection of transmission and distribution infrastructure. Source: Intel. Infrastructure Modernization. Spring 2021.
For more on integrating a distribution system to an RTO/ISO:
- Check out this presentation from DNV.
- DNV conducted an evaluation studying the integration of Lubbock Power & Light (LP&L) to ERCOT.
- The full study includes a system evaluation, option development, and screening, option analyses, preferred option selection, cost-benefit analysis, and final recommendations.
- Figure 6 below summarizes the integration approach:
Figure 6. ERCOT Integration Approach. Source: DNV. Presentation on Lubbock Power & Light ERCOT Integration Study. November 2015.
If you have materials (reports, press releases, videos, etc.) that you would like us to showcase on our website, it’s not too late to forward them. Additionally, start thinking about next month’s theme, Utility Communication and Broadband. We will be asking for content for our website and for your ideas for upcoming Policy and Technology Council meetings. All of this helps us share knowledge of what our members are doing with federal and state policymakers and other stakeholders. Thanks for helping us tell your stories!