Why Local Solar For All Costs Less:

A Roadmap for a Clean, Equitable, Low-Cost and Resilient Electricity Grid for Everyone �localsolarforall.org

Karl R. Rábago, Rábago Energy LLC

6 November 2023

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Conventional Thinking

• Large central power plants are cost-effective b/c of economies of scale
• Utility scale is cheapest, fastest way to meet clean energy goals
• Local solar + storage is too expensive and will increase rates

Paradigm Shift

• New and better models
• Scaling utility renewables AND local solar and storage leads to ratepayer savings
• We can build out a more resilient, equitable, and customer-driven grid AND save money, create jobs, and reduce pollution

WIS:dom®-P: Total System Planning Tool

• WIS:dom-P is a state-of-the-art, fully combined capacity expansion and production cost model, developed to process vast volumes of data. Resolution to 1 kw, 5 minutes (or less), and 1 km²
• It simultaneously co-optimizes for: (1) Capacity expansion requirements (generation, storage, transmission, and demand-side resources); and (2) Dispatch requirements (production costs, power flow, reserves, ramping and reliability).
• WIS:dom-P is a total system planning tool that provides:

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MORE & BETTER DATA PROCESSING

TOTAL SYSTEM PLANNING COORDINATION

LOCAL CLEAN ENERGY INTEGRATION

& OPTIMIZATION

What Does Integrate & Optimization Mean?

• WIS:dom-P co-optimizes and coordinates the utility-scale electricity grid (left) with the distribution grid (right) to find the overall least system cost.
• Co-optimize and coordinate means it considers distribution infrastructure requirements and determines when leveraging local solar + storage to serve local load and/or reduce peak load, �could lessen the need for some distribution infrastructure and forego additional utility-scale generation and transmission buildout.

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LOAD FLOW

BACK FLOW

Expanding Local Solar + Storage Saves $473B

• Optimizing and making initial investments in utility-scale and distribution level grid infrastructure and capacity drives huge long-term savings relative to traditional system planning.
• The savings captured in this chart include only monetary grid costs and benefits, it doesn’t include indirect societal benefits.
• Clean electricity (CE) under BAU costs $385 billion by 2050.
• Optimizing local solar + storage (DER vs BAU) saves > $300B.
• A clean grid with DER saves $88 billion vs. dirty BAU.
• Getting to a clean grid with DER saves $473B vs. BAU path.
• In addition to saving billions, the model shows expanding local solar + storage results in lower costs per kilowatt hour (total system costs divided by total generation), translating into lower rates and customer savings. Plus more jobs and reduced criteria pollutants.

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DER Savings vs. BAU

Cumulative Electricity Spending Savings

DER-CE Savings vs. CE

DER-CE Savings vs. BAU

*BAU = Business as usual, DER = Optimization of Local solar + storage, and CE = clean electricity targets

Why Did WIS:dom Find Cost Savings?

• Modeling that ENABLES COMMUNICATION between both sides of the grid (transmission & distribution) with WIS:dom demonstrates an ability for local solar and storage to reshape load, as observed from the utility-scale grid (i.e., above 69 kV).
• One consequence of this co-optimizing and coordinating utility-scale with distributed-scale is the reduction of volatility in the demand as observed by the utility-scale grid.
• A second consequence is a dramatic drop in the peak demand requirements as observed by the utility-scale grid — ~16% reduction in peak by 2050 attributed to local solar + storage in national modeling.
• The result is that more local solar + storage reduces net demand and smooths overall demand to enable access to lowest cost utility-scale generation – more utility wind and solar and less fossil firming capacity.
• By permanently easing stress on system during critical peak hours & reducing how much bulk-scale power is needed to serve the distribution grid, you don’t have to overbuild the system with expensive peaker plants and firming capacity.
• Savings in 85% of operating hours.

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Policymakers & Regulators Should

• Establish Clean and Consistent Policies to Scale Local Solar + Storage Today
• Continue and strengthen programs that support rooftop and community solar projects.
• Kickstart the storage market with incentive programs and develop long-term storage development plans.
• Adopt and improve complementary policies to reduce up-front costs for local solar such as permitting and interconnection.
• Ensure smooth and stable transitions for rate designs.
• Ensure that development of local solar is equitable and diverse; ensure benefits for environmental justice communities.
• Integrate and Optimize Local Solar + Storage into / through State Energy Planning
• Create new grid planning processes that require utilities to provide data that will help states unlock resource optimization.
• Use advanced modeling tools like Vibrant Clean Energy’s WIS:dom-P model in grid planning processes.
• Accelerate the pace of local solar + storage deployment in order to capture savings potential and set up for even more savings in the future.

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Questions

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