IST PVSolar Simulator Built for South Asia's Solar Engineers

IST PVSolar Simulator V9.0.10 takes a South Asian solar project from site data to a bank-ready report in one platform, using the standards, utilities and tariff rules that projects in the region actually face.

Why South Asia needs its own solar platform

Most PV design tools are built around European or US assumptions. A rooftop project in Pune, Colombo or Dhaka has a different checklist: DISCOM net-metering approval, CEA safety rules, BIS-certified modules, monsoon soiling, and depreciation rules such as India's 40% WDV.

Engineers usually bridge that gap by hand. They export a yield from one tool, rebuild the cable schedule in a spreadsheet and retype the financial model for the lender. Every hand-off adds rework and risk of error.

IST PVSolar Simulator removes those hand-offs. The selected country drives the standards cited on drawings, the utility named in approvals, the default tariff and the tax treatment in the financial model.

Native to South Asian utility frameworks

Choose a Country / Market once, and the simulator applies that market's codes, utility wording, tariff defaults and tax rules everywhere. India, Sri Lanka and Bangladesh have full local profiles; Pakistan, Nepal, Bhutan, the Maldives and Afghanistan use a South Asia regional profile with their own currency, VAT/GST rate and grid CO₂ factor.

India is the reference market. Designs follow:

• Design and installation: BIS IS 16169 for grid-connected PV design and DC wiring losses
• Safety and grid connection: CEA Regulations 2010 and the CEA Technical Standards for Connectivity to the Grid (2023 amendment)
• Earthing: IS 3043, with earth resistance of 1 Ω or less per CEA Regulations
• Components: IS 694 cables, IS 13947 breakers and IS 15707 meters
• Approved equipment: BIS-certified modules and inverters, plus the MNRE ALMM List-I module and List-II cell context
• Policy and grid factor: PM Surya Ghar residential subsidy slabs, DISCOM net metering and the CEA CO₂ baseline of 0.82 kg/kWh

All these values are indicative starting points and stay fully editable. If a rule changes, the administrator can update a country centrally. Each user can also save their own values for their market in the Database tab, and the simulator uses them in place of the built-in ones.

From site data to a bankable energy yield

The simulation engine runs at monthly, hourly (8,760 steps) or 15-minute sub-hourly (35,040 steps) resolution. The hourly and sub-hourly runs are the ones meant for bankable reports.

Solar resource. Import a NASA POWER hourly TMY or a PVGIS TMY built to ISO 15927-4, or enter the 12-month table by hand. Loading a measured hourly TMY automatically tightens the resource uncertainty from ±5% to ±2.5%.

Physics chain. Each hourly step follows the same sequence:

1. Perez (1990) anisotropic transposition converts horizontal irradiance to plane-of-array irradiance.
2. Martin–Ruiz incidence-angle losses and an air-mass spectral correction give the effective irradiance.
3. The Faiman model sets cell temperature, and a single-diode (De Soto 5-parameter) model gives module power.
4. DC losses and degradation are applied, then the inverter efficiency curve and true AC clipping.

Shading in 3D. Upload a drone orthomosaic (JPG, PNG or GeoTIFF, with optional KML, GeoJSON or LAS point-cloud files). Trace roofs and obstructions such as trees, parapets and chimneys, and lay out real panels. The tool returns an hourly shading profile instead of a single flat percentage.

Bifacial and trackers. An unlimited-sheds view-factor model calculates rear-side irradiance from albedo, mounting height and pitch. Single-axis trackers with backtracking are supported for ground-mount plants.

Local losses built in. Default soiling guidance is written for South Asian conditions: 2–3% for a typical Indian rooftop with monthly cleaning, and 4–6% for desert sites in Rajasthan and Gujarat cleaned weekly or every two weeks.

No .PAN or .OND files needed. Build any module or inverter model straight from the manufacturer's PDF datasheet. This matters in South Asia, where many local and ALMM-listed suppliers do not publish proprietary simulation files.

Electrical design deliverables, generated from the same model

Once the simulation runs, the electrical documents are built from the same design data. There is nothing to retype, and the drawings always match the yield model.

The wording follows the selected market. An Indian drawing names the DISCOM and cites the CEA. A Sri Lankan drawing names CEB / LECO and the PUCSL schemes. The Draft DPR can also draft the national and state policy chapter from a live web search for the project's country.

Bankability that lenders recognise

The financial model runs on the conservative P90 energy, not the P50 headline. Every ratio is tested against covenant thresholds the lender sets.

The path from yield to investment decision:

1. Uncertainty. Four sources are combined by root-sum-square: inter-annual variability (±5%), resource data (±5%, or ±2.5% with a measured TMY), model (±1.5%) and components (±2%). The result is P50, P75, P90 and P95 yields.
2. Project-level model. LCOE, NPV, IRR, ROI, profitability index, simple and discounted payback, and break-even tariff, with a year-by-year cash flow over the full project life.
3. Equity-level model. Project IRR, equity IRR, minimum DSCR over the loan tenure, and a CAPEX/Wp check against country-specific benchmark bands.
4. Monte Carlo risk. 20,000 trials by default across the 8,760-hour AC series, degradation, tariff and OPEX escalation. It reports P10, P50 and P90 ranges for NPV, equity IRR, LCOE and DSCR.
5. Risk score and report. A 0–100 composite from Investment Grade to Speculative, with a hard override if NPV or DSCR fails. A lender-facing Bankability Assessment Report records the preparer, the reviewer and where the resource data came from.

South Asian tax treatment is built in. Choose WDV, SLM or a custom depreciation schedule, then apply the country preset with one click. India's preset sets 25.17% tax under Sec. 115BAA with 40% WDV. It also notes that additional depreciation is available only under the old tax regime.

Export credit is modelled per year. Self-consumed energy is valued at the retail tariff and exports at the scheme rate. A scheme can change after its term, for example Sri Lanka's 20-year Net Accounting tiers, and the revenue for each year reflects that.

Who it is for, and how to start

The platform serves everyone who touches a South Asian solar project between concept and financial close:

• Rooftop and C&I EPC contractors who need a DISCOM-ready design, cable schedule and client proposal on the same day
• Utility-scale developers sizing ground-mount and tracker plants with 3D terrain, row pitch and true inverter clipping
• Technical consultants and due-diligence engineers who need P90 yields, transparent loss chains and a reproducible report
• Lenders and investors reviewing DSCR, equity IRR and the risk score against their own covenants
• Students and researchers, through the Research tab: IEC 61724-1 accounting, sensitivity analysis, uncertainty, and SCADA benchmarking against measured plant data

Start on the Free Plan. Every new member is activated on the Free Plan automatically at sign-up. It covers project setup, orientation, module and inverter selection, sub-array design and the full simulation engine. Reports carry a DEMO VERSION watermark.

Upgrade when the project needs it. Paid plans unlock 3D Shadow Analysis, Economic Evaluation and Bankability, the component databases, and EPC Proposals and BOQ. The Research tab comes with the higher tiers. If a paid plan lapses, the account returns to the Free Plan automatically.

One design, one source of truth

IST PVSolar Simulator V9.0.10 replaces the chain of separate tools and spreadsheets behind a South Asian solar project. One design drives a P90 yield, a CEA- and IS-compliant electrical package and a lender-ready bankability report.

Because the market profile carries the region's real rules, the numbers start close to correct. That covers DISCOM net metering, Sri Lanka's PUCSL tiers, Bangladesh's 2025 net-metering guidelines and India's 40% WDV. Engineers spend their time on the design, not on re-keying data.

Create a free account at istpvsolarsimulator.com and run your first 8,760-hour simulation today.

Tariffs, tax rates and policy rules in the simulator are indicative starting points. Confirm the current values with BIS, CEA, MNRE, your utility and a tax adviser before issuing a bankable report.