Loss waterfall (9 steps)
From GHI on the roof through transposition, soiling, temperature, cables, inverter, and availability — every cut in kWh, like a worked BVJ rooftop example on the home page.
Why teams search for a PVsyst alternative in India
- Indian codes at the site — IS 875 wind zone, IS 1893 seismic class, and DISCOM context should resolve from the pin, not from a US or EU default.
- Weather diversity — PVGIS alone is not enough for every Gujarat rooftop or Rajasthan ground-mount; compare NASA POWER, NSRDB, SARAH-3, and MOSDAC in the same run.
- Readable losses — tenders and banks ask how you got from sunlight to P50; a single PR line is not a loss trail.
- Speed to PDF — pin, kit, year, and bankable report in one browser workflow instead of a week of desktop exports.
What REEOS adds for solar yield simulation
Safety before simulate
Block unsafe string lengths on cold mornings and check DC cable ampacity at peak roof temperature before the yield engine runs.
Validated on real plants
40 MW ground-mount, ten metered years, unnamed in public materials — REEOS predictions tracked against actual generation.
Solar + BESS tenders
One workspace for production and storage when Enterprise teams bid multi-site solar and BESS packages.
REEOS vs PVsyst (honest comparison)
PVsyst remains widely named for utility-scale lender reports worldwide. REEOS competes where Indian compliance, cloud collaboration, and transparent losses matter for weekly EPC and IPP bids.
| Capability | REEOS | PVsyst (typical) |
|---|---|---|
| Hourly yield / loss physics | Yes — visible waterfall | Yes — detailed engine |
| IS 875 / IS 1893 at pin | Built in | Manual / external |
| Five weather sources compared | PVGIS + 4 more, locked in PDF | Meteonorm / PVGIS workflows |
| Cloud browser workspace | Yes | Desktop-first |
| Bankable PDF + datasheets | One run | Export reports |
PVsyst alternative FAQ
- Is REEOS a PVsyst alternative for India?
- REEOS is built for the same bankable yield workflow Indian EPCs use PVsyst for — hourly loss physics, PR/CUF, degradation, and lender-facing PDFs — with IS 875, IS 1893, DISCOM context, and five weather sources resolved at your site pin in the browser.
- Can REEOS replace PVsyst on every project?
- For rooftop and commercial bids where you need Indian codes, multi-source weather, and a readable loss trail in one run, teams use REEOS as the primary simulation tool. Some utility lenders still name PVsyst in term sheets; REEOS is positioned as the India-native cloud alternative with comparable transparency, not a black-box PR.
- Does REEOS support PVGIS and bankable P50 reports?
- Yes. REEOS compares PVGIS with NASA POWER, NSRDB, SARAH-3, and MOSDAC, locks the best dataset for the run, and prints citations and percentiles in the PDF.
- How is REEOS different from HelioScope or Aurora for India?
- REEOS focuses on Indian compliance at the pin, cold-morning Voc blocking, peak-temperature cable checks, and a nine-step kWh waterfall — features many global design tools do not list on their public pages for India.