Nashville premieres Renewable Portfolio Standard dashboard, shows gap to 2041 municipal goal

Members of the Sustainability Advisory Committee on Sept. 1 heard the “world premiere” of a public dashboard that tracks Metro Nashville’s Renewable Portfolio Standard (RPS) and projects progress toward a 2041 goal of offsetting municipal electricity use with tier‑1 renewables.

The dashboard, presented by Jennifer Westerholm, assistant director of the Division of Sustainability in the Department of General Services, displays electricity consumption by sector, projected future use through 2041, and how much on‑site solar, renewable energy credits and regional utility supply (principally Tennessee Valley Authority, TVA) would contribute to annual RPS targets. "I'm really excited to provide you all with the world premiere of our Renewable ... Standard Dashboard," Westerholm said during the presentation.

The tool separates municipal electricity use into four sectors: city lights (street and traffic lights), Metro Nashville Public Schools, general government operations and Metro Water Services, the last of which the presentation identified as the single largest municipal electricity consumer. Using utility billing and benchmarking data for 2019–2024 and projections to 2041, the dashboard models a baseline electricity demand and the annual percentage of that demand that must be offset by tier‑1 renewables. Westerholm noted the ordinance the City Council adopted in 2019 requires the municipal RPS and that the dashboard will make progress transparent to the public.

The presentation showed example figures for 2025 — a year with a 35% RPS target — and modeled TVA supply under three scenarios (minimum, average and maximum renewables under TVA’s integrated resource plan). The dashboard also displays on‑site and off‑site contributions: Westerholm said on‑site installations and renewable energy credit (REC) purchases currently account for a small fraction of the target (she cited roughly 1.4% from on‑site renewables and 4.8% from TVA in the 2025 example), and that Metro would need substantially more capacity over time. The dashboard’s megawatt view estimates Nashville would need about 568 megawatts of tier‑1 renewable capacity by 2041 to offset projected municipal electricity demand.

Committee members pressed staff on feasibility and constraints. "Is it even possible to get to those goals?" asked a member, noting TVA’s resource choices and limits on what Nashville Electric Service (NES) can supply. Westerholm and Erin Mello, the dashboard’s technical lead, said progress will rely on a mix of strategies: large‑scale utility solar via programs like TVA’s Green Invest, continued on‑site installations at Metro facilities (the dashboard assumes an aggressive one‑megawatt‑per‑year pace in one scenario), solar services agreements to spread capital costs, and purchasing RECs where direct generation is not available. Westerholm said upcoming utility‑scale projects with NES and TVA could produce a step change in capacity and noted an expected addition of roughly 4 megawatts in the next year due to recent capital investments in Metro buildings.

The committee also discussed demand‑side reductions. Staff emphasized that reducing municipal electricity consumption through energy efficiency makes the RPS easier to meet: "energy efficiency comes first, then you do the solar to meet what you need to meet," Westerholm said, and highlighted work underway to identify fast‑payback energy conservation measures across a roughly 100‑building portfolio.

Public comment before the presentation included an announcement from Paul Sluents of Tennessee Interfaith Power and Light about an energy‑and‑sustainability workshop for houses of worship on Nov. 1 at Second Presbyterian Church; that notice was unrelated to the dashboard content but noted at the meeting start.

Westerholm said the dashboard will be updated monthly and staff expect to publish the public link within a month of the presentation. Committee members requested future additions, including alternate efficiency scenarios ("good, better, best") layered against the demand projection, and comparative context showing how Nashville’s municipal progress compares with similarly sized cities. Staff agreed to return with comparative research on request.

The dashboard is intended as a public, regularly updated tool to track annual compliance with the municipal RPS, show dependencies on TVA and utility partners, and make visible the relative contribution of on‑site solar, RECs and regional supply under multiple scenarios. Staff cautioned the path to 100% depends on many factors — utility plans, partnership opportunities and continued capital or financing mechanisms — and recommended that the committee pair the dashboard with ongoing energy‑efficiency work to reduce the baseline electricity demand.