TNB Bill to Solar Size (kWp) & Offset Calculator — RP4 Estimate
Anggar: bil TNB bulanan → saiz sistem solar (kWp) & offset
Isi bil TNB bulanan dan klik Anggar saiz sistem — anggaran kWh, kWp dan band kos akan muncul di sini.
Pemalar tarif RP4, band kos dan SuRIA dibaca dari daftar fakta bertarikh (relay kajian DR13, era 2026-09; semakan langsung TNB/SEDA tidak dilakukan). Model ini TIDAK memodelkan SST dan cas retail — anggaran untuk perbandingan ruang sahaja.
Kapsul: enter your monthly TNB bill — this calculator back-computes the kWh usage on layered RP4 tariffs, estimates the system size (kWp) for the offset target you choose, and shows a market installation cost band. It is a space-cost estimate only: not a quotation, not a savings guarantee. NEM 3.0 has closed; the current residential path is Solar ATAP.
How the calculation works (fully transparent)
| Step | Formula | Constant source (checked 2026-09-27) |
|---|---|---|
| Estimated usage | bill ÷ layered rate by block | base [solar-grid-rm-kwh-band-low]/kWh up to [solar-tariff-block-kwh] kWh, [solar-grid-rm-kwh-band-high]/kWh after; era AFA from [solar-afa-rm-kwh-sep2026]/kWh (optional) |
| System size | target generation ÷ specific yield ÷ days | specific yield is an UNVERIFIED configuration constant (3.5 kWh/kWp/day) — confirm with your EPCC |
| Installation cost | kWp × market price band | [solar-rm-per-kwp-low]–[solar-rm-per-kwp-high] per kWp (market research, not a quotation) |
| SuRIA rebate | kWp × rebate rate, capped | [solar-suria-rebate-rm-kw]/kWac capped at [solar-suria-rebate-cap-rm], limited quota — check SEDA |
Why there are no “today” numbers on this page
RP4 tariffs move: the AFA component is recomputed monthly and rebate quotas change. That is why the constants are read from the dated fact registry — if a key is missing, the calculator stops with an honest message instead of guessing. This estimate also does not model SST and retail charges; it is a space-comparison tool, not a bill replacement.
Verdict: use this calculator for sizing space and cost bands, then request quotations from a SEDA-registered installer (RPVSP). Read the RP4 tariff explainer and SuRIA rebate pages before deciding.
Read also: home solar installation cost · solar hub