1. Irradiance & Physics Engine
The resource and yield calculation core: how sunlight on a horizontal plane becomes AC energy at the meter, resolved at hourly or sub-hourly granularity rather than typical-day approximation.
| Feature / Criterion | Capability | Standard / Reference | Status |
|---|
| Transposition model | Perez anisotropic sky model resolves circumsolar and horizon-brightening components of diffuse irradiance on the tilted plane, selectable alongside an isotropic model for comparison. | Perez et al., 1990 — Solar Energy | ✓ Implemented |
| Diffuse decomposition | Erbs correlation splits measured/TMY global horizontal irradiance into direct-normal and diffuse-horizontal components where the source data does not already separate them. | Erbs, Klein & Duffie, 1982 | ✓ Implemented |
| Cell/module temperature | Multiple thermal models (Sandia/King, Faiman Uc/Uv, simple NOCT) are benchmarked against each other in a dedicated Temperature Characterisation research panel, rather than relying on one fixed assumption. | King et al., SAND2004-3535; Faiman, 2008 | ✓ Implemented |
| Electrical (I-V) model | Single-diode equivalent-circuit model underlies module power output, capturing irradiance and temperature dependence beyond a linear derate. | De Soto, Klein & Beckman, 2006 | ✓ Implemented |
| Angle-of-incidence loss | Martin & Ruiz analytical IAM model accounts for reflection losses at low sun angles, applied per timestep rather than as a flat annual derate. | Martin & Ruiz, 2001 | ✓ Implemented |
| Spectral mismatch | Dedicated Spectral Research module corrects for spectral deviation from AM1.5G across mono-Si, CdTe and other cell technologies, by climate zone. | Solar Energy Materials & Solar Cells lit. | ✓ Implemented |
| Time resolution | Simulation engine runs at hourly and sub-hourly (sub-15-minute) resolution, not only monthly or single-typical-day approximation, enabling ramp-rate and clipping analysis. | IEC 61724-1 monitoring intervals | ✓ Implemented |
| ML forecasting research | An AI/ML research module trains short-term yield forecasting models directly on the engine's own physics-consistent hourly output, keeping training data internally consistent with the simulation physics. | Applied Energy / Energy & AI lit. | ✓ Implemented |
2. Shading
Row-to-row, near-horizon, and far-horizon shading loss — modeled multiple independent ways and benchmarked against what the simulator itself actually applies to the run.
| Feature / Criterion | Capability | Standard / Reference | Status |
|---|
| Multi-model cross-validation | Five independently implemented shading-loss models — ray-casting (geometric), SkyView factor, isotropic diffuse, Perez anisotropic, and linear — are computed side by side in one Model Comparison table, alongside the loss the engine actually applied to the current run as a ground-truth reference row. | Multi-model, cross-checked | ✓ Implemented |
| 3D horizon modeling | Near-horizon (inter-row) and far-horizon (terrain/obstruction) shading are modeled from an explicit 3D geometry, not a flat horizon-line estimate. | Geometric ray-tracing | ✓ Implemented |
| Electrical shading chain | Shading loss propagates through a string-mismatch and bypass-diode-aware electrical model, rather than only derating incident irradiance. | electrical_shading engine module | ✓ Implemented |
| Module-geometry-aware layout | Physical array-table drawing (columns × rows of modules per mounting table) is derived automatically from module dimensions and string sizing, feeding directly into the shading and cable-schedule calculations. | array table | ✓ Implemented |
3. Bifacial & Layout
Rear-side gain, ground-cover ratio, and tracker geometry — the design variables that most influence energy density per hectare.
| Feature / Criterion | Capability | Standard / Reference | Status |
|---|
| Bifacial gain modeling | Dedicated Bifacial Gain research module quantifies rear-irradiance contribution as a function of albedo and row spacing / GCR, rather than a fixed bifaciality bonus. | Sun, Khan, Deline & Alam, 2018 | ✓ Implemented |
| Row spacing / GCR optimization | Optimum row spacing is computed in Research and can be applied back to the design with one click, closing the loop between analysis and layout rather than requiring manual re-entry. | "Apply Optimum Row Spacing" workflow | ✓ Implemented |
| Single-axis tracker (SAT) workbench | Dedicated SAT research area models backtracking geometry, GCR impact, and DC:AC ratio sweeps specific to tracked arrays, separate from the fixed-tilt engine. | Duffie & Beckman tracker geometry | ✓ Implemented |
| Fixed-tilt vs SAT comparison | A built-in comparative study runs both mounting strategies on the same site/weather dataset for direct yield comparison. | 8760-hour comparative simulation | ✓ Implemented |
4. India Regulatory [Exclusive to IST PVSolar]
Compliance and cost fields specific to the Indian regulatory and procurement environment, built into the workflow rather than left to a separate spreadsheet — the category most competitor tools (built for European/US markets) do not address at all.
| Feature / Criterion | Capability | Standard / Reference | Status |
|---|
| Electrical safety compliance | Protection & cable schedule generator applies Indian electrical safety regulation directly to cable sizing and protection ratings, alongside international cabling standards. | CEA (Safety & Elec. Supply) Regs., 2010; IEC 60364-7-712 | 🏅 Exclusive |
| Domestic content / ALMM | A dedicated field captures ALMM-listed status and Domestic Content Requirement / BCD compliance as part of system parameters, relevant to India-specific procurement eligibility. | MNRE ALMM Order | 🏅 Exclusive |
| DISCOM / net-metering integration | DISCOM consumer ID and offtake arrangement (e.g. 25-year PPA with DISCOM) are captured as first-class project fields feeding the economic and EPC workflow. | State DISCOM net-metering regulations | 🏅 Exclusive |
| India-indexed cost reference | CAPEX reference-cost table is denominated in ₹/unit for major line items (modules, inverter, structure, DC/AC cable, earthing, net-meter/DISCOM charges, installation, AMC) with applicable GST banding, instead of a generic $/W assumption. | Indicative India market rates; GST 0–18% | 🏅 Exclusive |
| Benchmark vs India | A dedicated comparison panel positions a given project's key metrics against typical Indian utility-scale/rooftop benchmarks. | MNRE / CEA / industry benchmarks | 🏅 Exclusive |
| Agrivoltaics & land-use | Land Equivalent Ratio module quantifies co-located crop-and-solar land-use efficiency, relevant to India's land-scarcity context and emerging agrivoltaic guidance. | MNRE agrivoltaics guidance (emerging) | 🏅 Exclusive |
| Platform-wide standards banner | Every screen displays the governing standards set applied throughout the tool, keeping compliance visible rather than buried in an appendix. | IEC 61724-1 · IEC 61853 · BIS IS 16169 · CEA · MNRE | 🏅 Exclusive |
5. Financial & Bankability
The outputs a lender's technical advisor actually asks for: exceedance-probability yield, sensitivity of returns to key assumptions, and a documented evidentiary trail.
| Feature / Criterion | Capability | Standard / Reference | Status |
|---|
| P50–P95 exceedance yield | Monte Carlo propagation of resource, soiling, degradation, availability and model uncertainty produces a full P50/P75/P90/P95 exceedance table with a variance-contributor breakdown, not a single deterministic number. | IEC 61724-3 energy evaluation | ✓ Implemented |
| Bankability Assessment Report | A dedicated report generator compiles the technical and financial evidence a lender's independent engineer typically requests into a single document. | Bankability Assessment Report module | ✓ Implemented |
| Financial risk tornado | A tornado chart ranks financial and technical assumptions (tariff, OPEX, degradation, DC:AC, etc.) by their effect on returns/LCOE in one view. | Sensitivity tornado analysis | ✓ Implemented |
| Financing & OPEX structure | A full financing-structure and OPEX module feeds the Economics and is cross-linked into the Research uncertainty and tornado panels, so financial and technical assumptions stay consistent. | Economic Evaluation | ✓ Implemented |
| Evidentiary export trail | One-click BibTeX citation export, per-table CSV/LaTeX export, and a Zenodo-format dataset package give a documented, DOI-mintable evidence trail supporting due-diligence submissions. | Zenodo deposit metadata schema | ✓ Implemented |
6. Accuracy & Validation
How the platform's own outputs are checked — against field data, against an incumbent industry tool, and against themselves over time.
| Feature / Criterion | Capability | Standard / Reference | Status |
|---|
| SCADA benchmarking | Measured-vs-simulated validation against SCADA data, with IEC 61724-1-compliant filtering of the comparison dataset. | IEC 61724-1 | ✓ Validated |
| Multi-model internal cross-check | Shading and thermal calculations are each computed by multiple independent models and reconciled against the engine's own applied result, rather than trusting a single implementation. | See §2.0, §1.0 | ✓ Validated |
| Versioned run traceability | Research Notebook stores a stable, shareable ID for every saved run's exact parameter set, so a reviewer or auditor can reproduce or re-check a specific result on demand. | Research Notebook (versioned history) | ✓ Validated |
| Documented methodology | Built-in Journal Papers Guides specify the exact methodology, standards, and datasets each module's output is intended to support — the same rigor a peer reviewer or lender's engineer would expect to see stated explicitly. | Journal Papers Guide (Research) | ✓ Validated |
7. Multi-Currency Engine [Exclusive to IST PVSolar]
Currency is a single, global setting that propagates through every part, chart, and generated report — with proper locale-aware number formatting per market, not just a swapped symbol.
| Feature / Criterion | Capability | Reference | Status |
|---|
| Native currency selector | 20 currencies are selectable from a single source-of-truth setting, applied simultaneously to Economics, simulation charts, the Database and every generated report. | Settings → Currency Symbol | 🏅 Exclusive |
| Locale-aware formatting | Each currency carries its own number-grouping locale (e.g. Indian lakh/crore grouping for ₹, German thousands-grouping for €, standard grouping for $/£), so figures read naturally to a local reviewer rather than in a foreign convention. | CURRENCIES locale table | 🏅 Exclusive |
| Market-appropriate scaling unit | Large figures are auto-scaled to the unit a market actually uses — Lakhs (L) for ₹/৳/₨, Thousands (K) for most others — rather than displaying raw unscaled totals everywhere. | curScale() / curUnit() | ✓ Implemented |
| Live re-scaling on change | Switching currency mid-session recalculates and redraws revenue, cash-flow and life-cycle charts in the new currency immediately, without re-running the simulation. | applyCurrency() → chart re-draw | ✓ Implemented |
| Coverage breadth | INR, USD, EUR, GBP, JPY, PKR/LKR/NPR, BDT, AUD, CAD, BRL, ZAR, THB, MYR, PHP, IDR, AED, SAR, KRW, NGN, and CHF — spanning South Asia, North America, Europe, ASEAN, the Gulf, Africa and Latin America in one platform. | 20-currency table, §2.0 below | 🏅 Exclusive |
8. Country/Region-Specific CAPEX/Wp Bankability Bands [Exclusive to IST PVSolar]
Installed cost per watt varies materially by country — labour, land, import duty and local EPC competition are not the same in Lagos as in Zurich. Rather than one fixed USD threshold, every currency carries its own editable low/high CAPEX/Wp band, tracked separately for utility-scale ground-mount and rooftop/C&I (rooftop runs structurally ~30–40% higher per Wp due to mounting complexity and smaller BOS economies).
| Feature / Criterion | Capability | Reference | Status |
|---|
| Segment-aware bands | Utility-scale and rooftop/C&I are tracked as structurally distinct cost bases per market, rather than one blended figure that misrepresents either segment. | DEFAULT_CAPEX_BANDS table | 🏅 Exclusive |
| Auto-segment detection | The applicable segment is inferred automatically from Project Type (Ground-Mounted → utility, Rooftop Commercial/Residential → rooftop), with no manual toggle required. | getCapexSegment() | ✓ Implemented |
| User-editable, persisted | Every band is an editable field on the Database, so a user can update thresholds to current local EPC market pricing; edits persist across sessions and a one-click reset restores platform defaults. | Database → CAPEX/Wp Bankability Bands | 🏅 Exclusive |
9. Automated CAPEX Benchmark Verdict
The Bankability Assessment Report doesn't just display a project's CAPEX/Wp — it benchmarks that figure against the matching country/segment band and states a verdict in the report's own language.
| Feature / Criterion | Capability | Reference | Status |
|---|
| Reasonable | CAPEX/Wp at or below the market's "low" threshold is reported as reasonable — within the typical bankable range for that country and segment. | Bankability Report §5.2 | ✓ Automated |
| Slightly elevated | A figure between "low" and "high" is flagged as slightly elevated versus the typical range, with a note that it should be benchmarked against comparable regional projects. | Bankability Report §5.2 | ✓ Automated |
| Materially above benchmark | A figure above the "high" threshold is flagged as materially above the typical bankable range, explicitly calling for cost benchmarking against comparable regional projects before proceeding. | Bankability Report §5.2 | ✓ Automated |
| Currency-native phrasing | The verdict sentence itself is generated in the active currency and market label (e.g. "…within the typical India utility-scale ground-mount bankable range (up to ₹ 55/Wp)"), not translated after the fact from a USD baseline. | capexBenchmarkNote generator | 🏅 Exclusive |
10. Country, Political & Currency Risk
Content DFIs, ECAs and international lenders expect beyond the core technical/financial model, for projects where the lender's exposure is cross-border.
| Feature / Criterion | Capability | Reference | Status |
|---|
| Revenue vs. debt currency | A dedicated field captures whether project revenue and debt service sit in the same currency, flagging cross-currency exposure explicitly rather than leaving it implicit. | Country, Political & Currency Risk | ✓ Implemented |
| FX hedge status | A free-text field records the hedging approach (e.g. "Natural hedge — no cross-currency exposure"), surfaced directly in the Bankability Report's country/currency risk section. | fxHedgeStatus field | ✓ Implemented |
| Automatic mismatch risk rating | The report auto-rates the revenue/debt currency alignment (Medium by default, High when a mismatch is entered without a hedge), rather than requiring the preparer to write the risk rating manually. | Bankability Report §8.2 | ✓ Automated |
| DFI/ECA-grade report sections | Beyond the core technical/financial assessment, the report includes Conditions Precedent, Offtaker Credit Risk, Legal & Regulatory Matrix, Insurance Program, Country/Currency Risk, an ESAP, Tax & Fiscal Incentives, and Stress Scenarios — the additional content international lenders typically require. | Bankability Report §7–10 | 🏅 Exclusive |
| Tax & fiscal incentive caveat | The report explicitly flags that depreciation schedules, tax holidays and import duty treatment vary materially by country and directly affect after-tax IRR, prompting confirmation against the project's actual jurisdiction. | Bankability Report §9 | ✓ Implemented |
Why This Makes It Novel Software
No single capability above is unprecedented in isolation — transposition models, bankability reports, and SCADA benchmarking each exist elsewhere as standalone tools. What is novel is that IST PVSolar Simulator carries a physics-grade multi-model engine, India-specific regulatory and cost fields, lender-grade bankability outputs, and independent accuracy validation in one browser-based workflow, with every stage traceable back to the exact parameters that produced it. For an EPC preparing a DPR or a lender's technical advisor conducting due diligence, that removes the usual need to stitch together a Western-market simulation tool, a separate India-compliance checklist, a bespoke Excel bankability model, and an ad-hoc benchmarking script into one submission.
IST PVSolar Simulator instead treats currency and country-typical CAPEX/Wp as first-class, structured data: 20 currencies with proper locale formatting, each carrying its own editable utility-scale and rooftop/C&I bankability band, feeding automatically into a benchmark verdict and a full DFI/ECA-grade risk section — without the user ever leaving the platform or rebuilding a benchmark model in a spreadsheet. That combination of breadth (20 markets), structure (two segments per market, not one blended figure), and automation (verdict language generated, not hand-written) is what turns a single-market simulation tool into one genuinely usable for global EPC and lender due diligence.
