Years to recover net upfront capex (--)
Discounted: --Make sunlight make sense.
Audit installer quotes, separate avoidable electricity bill charges from fixed fees, and model 25-year solar and battery cash flows with explicit data provenance.
Your payback & return telemetry.
Present value after discount hurdle
Profitability Index: --Annualized effective return on capital
Net ROI: --Expected site-specific generation
Opt Tilt: --Household demand covered by solar + storage
Avoided bill + export revenue minus O&M
25-Yr Cumulative: --Discounted lifecycle cost per kWh produced
vs Retail: --25-year avoided grid emissions from self-use
Grid factor: --Monthly generation, self-use & demand.
Stacked direct self-use, battery shifting, and grid export against monthly household load.
The cumulative return curve.
Nominal cumulative net cash flow (solid) and discounted NPV trajectory (dashed).
Where your energy goes.
Annual PV allocation and automated assumption diagnostics.
One-click optimization levers.
Quantified NPV gain from each marginal adjustment to your current setup.
Utility Bill Decomposer & Multi-Quote Comparator.
Separate non-avoidable fixed standing charges from your true avoidable per-kWh rate, and benchmark up to 3 installer bids side-by-side using the active climate & dispatch engine.
Solar self-consumption only offsets variable per-kWh charges, never fixed standing or capacity fees.
Value String Bid
High-Eff N-Type Bid
Solar + 10 kWh Storage
Illustrative 36-City Reference Atlas.
Every city card computes indicative Payback, NPV, and Year-1 Generation for your current 5.5 kWp array using illustrative regional reference parameters (unverified until live PVGIS is queried and local utility tariffs are confirmed).
National Solar Policy & Incentive Directory.
Datasheet Reference Specs. Compatibility Checked.
Compare commercial N-Type IBC, HJT, and TOPCon solar modules, micro/hybrid inverters, and LFP home batteries from manufacturer datasheets. Applying a profile updates modeled degradation, footprint, inverter loss, and reference cost.
Photovoltaic Module Reference Profiles.
Solar Inverters.
Home Battery Systems.
Built for your roof.
Start with your address, array size, and panel geometry. Climate production and geometry efficiency factors update automatically.
Where will it live?
Search any global city via Open-Meteo Geocoding or select a preset.
Define your solar array & geometry.
Generation is calculated using this exact tilt, azimuth, and mounting setup.
Roof-fit sketch.
Area-based planning using your active module footprint (2.00 m²).
Do not buy panels based on this area estimate alone. Confirm structural loads, setbacks, walkways and shading.
Estimates historical climate output for the chosen coordinates, geometry and mounting.
Every hour matters.
Simulate 24-hour solar-to-load dispatch across residential, remote-work, and commercial profiles, test smart midday load shifting, or import 8,760-hour meter CSVs.
Your electricity demand.
Configure annual consumption, seasonal shape, and direct daytime overlap.
Until you import matching 8,760h data, this percentage sets baseline direct daytime self-consumption.
Upgrade to 8,760-hour fidelity.
Match hourly consumption against 8,760-hour historical solar irradiance.
UTC-aligned 8,760-hour year, consumption in kWh. Processed 100% locally in your browser.
No meter file loaded.
Hourly solar series not loaded.
Consumption meets generation & battery SOC.
Interactive 24-hour dispatch showing solar output, home demand, and battery state-of-charge.
Power for after sunset.
Compare PV alone with PV plus battery and smart load shifting. See the exact incremental NPV, payback delta, and round-trip efficiency loss.
Configure your LFP battery.
Includes conversion losses, inverter charge/discharge limits, and annual capacity fade.
Storage value depends heavily on the spread between avoidable retail import rate and export compensation.
Storage is a choice, not an assumption.
See whether extra self-consumption pays for the installed battery in your specific scenario.
PV-Only vs. PV + Storage vs. Smart Load Shifting.
Side-by-side comparison across self-consumption, autonomy, IRR, NPV, and simple payback.
| Configuration | Annual Self-Use | Energy Independence | Internal Rate (IRR) | Net Present Value | Simple Payback |
|---|
Explore the upside.
Test marginal levers, inspect the 3×3 Yield-vs-Escalation sensitivity matrix, right-size your array, and save up to 12 scenarios locally.
Three levers worth testing.
Each delta is recomputed from your current inputs, not a generic savings claim.
How robust is the return?
Deterministic stress scenarios combining PV yield and retail tariff shifts.
PV Yield Multiplier vs. Utility Tariff Escalation.
Modeled Net Present Value (NPV), Internal Rate of Return (IRR), and Simple Payback across 9 combined climate and energy-inflation futures.
| Tariff Escalation \ PV Yield | 0.90× Yield (Cloudy / Shaded) | 1.00× Yield (Baseline Climate) | 1.10× Yield (High Irradiance / Bifacial) |
|---|
Which array size fits your economics?
Compare 6 array capacities scaled to your current location and consumption profile.
Keep your best ideas.
Saved locally in your browser. Export JSON for a full project backup.
Every number. Accounted for.
Investment, annual cash flows, avoided electricity, export payments, debt amortization, discounting, maintenance and replacements.
Actual price assumptions.
Replace defaults with the variable part of your real bill and installer quote.
Long-term financial & degradation assumptions
Positive NPV means the modeled investment exceeds the discount-rate hurdle. It is not a guarantee.
Lifetime cash-flow ledger.
Annual production, savings, export income, operating costs, and cumulative balance.
| Year | Production | Self-use | Export | Bill avoidance | Export income | Opex / replacement | Net cash | Discounted CF | Cumulative |
|---|
Evidence over exaggeration.
Every climate dataset, hardware specification, degradation rate, and regulatory tariff benchmark in Aurora v7.0 is traceable to primary scientific and industry sources.
EU JRC PVGIS 5.3 & NREL NSRDB
36 benchmark cities use PVGIS-SARAH3 (2005–2023) and NREL PVWatts v8 / NSRDB solar irradiation series, supplemented by live PVGIS edge proxy and Open-Meteo satellite radiation APIs.
EU JRC PVGIS 5.3 Documentation ↗NREL Cost & Degradation Physics
System capex and degradation curves reference NREL US Solar Cost Benchmarks ($2.95–$3.25/W), Jordan & Kurtz (0.5%/yr median c-Si), and 2026 N-Type TOPCon/HJT/IBC linear warranties (0.25%–0.40%/yr).
NREL Solar Cost Benchmark ↗2026 Global Tariffs & Net Billing
National policy cards reflect 2026 rules including Greek Net Billing (ΔΕΔΔΗΕ 20-yr day-ahead contracts), German EEG 2026 & 0% VAT, Spanish Surplus Compensation, and California NEM 3.0.
Global Net Metering Comparison ↗The information behind your report.
Practical due diligence & assumption audit.
Verify these items against your physical roof and utility contract before signing an installation quote.
Transparent Governance & Buyer Protection.
Clear operational boundaries, local-first data privacy, and support channels.
Local-First Processing
Imported 15/30/60-minute electricity meter CSVs and quote figures are parsed in-memory in your browser. Scenarios are stored in your browser's localStorage and can be exported or cleared at any time.
Decision Aid, Not a Site Survey
SolarPayback Aurora provides independent financial and physical modeling. It does not replace a licensed structural engineer's roof load inspection, on-site shade measurement, licensed electrician sign-off, or tax advisor review.
pilot & Audit Support
This standalone application provides full unrestricted access to the quote & bill analyzer and downloadable decision brief with zero paywall lock-in. For technical questions or data corrections, export your Project JSON snapshot.
PVGIS and NREL benchmarks describe historical solar resource; they do not inspect your exact roof obstacles, predict future retail electricity prices, verify your utility bill, guarantee a subsidy or replace licensed electrical engineering or tax advice. SolarPayback Aurora stores scenarios locally in your browser.