Is solar worth it at your address?

An independent 25-year cashflow model. California is modeled in depth (NEM 3.0, 2.6 million real installs). Oregon — especially Central Oregon around Bend and Redmond — is first-class. Type a California ZIP to see a score on this page.

2.6M install records 2,593 CA ZIPs scored NEM 3.0 · 1:1 NEM 30% federal ITC Open source

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Read the technical paper

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City reports

Full 25-year cashflow charts for California cities plus 12 Oregon locations (Bend, Redmond, Sisters, Portland, and more) — LCOE, payback, NPV, and the recommendation.

California ZIP heatmaps

Viability across all 2,593 California ZIP codes, with confidence from real Berkeley Lab installation counts.

Technical paper

OLTP/OLAP architecture, DuckDB warehouse, 25-year financial model, URDB staleness guard, and verification.

Source code

Pipeline, tests, and the FastAPI quote app. Run a live address locally, or fork it.

What this is

A transparent answer to “is rooftop solar worth it here?” — not a sales funnel. Production comes from NREL PVWatts. California IOU export credits use NEM 3.0 avoided-cost rates (~$0.055/kWh). Oregon currently offers 1:1 net metering. Install costs and market maturity come from Berkeley Lab Tracking the Sun (2.6 million residential records).

The viability score (0–100) is 25% solar resource, 50% economics (LCOE, payback, NPV), 15% site fit, and 10% local market maturity. Scores of 65+ are “Good” for a typical homeowner under these assumptions. ZIP lookup on this page is a California centroid model; city reports use a live PVWatts pull for a representative ZIP.

Outside the US, NREL can still estimate production. Financials need a local electricity rate — the open-source app accepts that as an input and turns off the US federal ITC.

Started as a San Jose State DATA 201 project. Maintained by Scott Nelson.