Indonesia Solar (PLTS) Calculator for Home, Business & Off-Grid

For a home with a PLN bill of Rp 1–2 million/month, a typical capacity is 3–5 kWp. Based on Q1 2025 market prices (≈ Rp 12.5 million/kWp all-in, excl. VAT), the total CapEx is around Rp 35–55 million — including mono PERC panels, an on-grid inverter, mounting, cabling, EPC installation, and SLO. Realistic market range: Rp 11–15 million/kWp depending on panel brand, inverter brand, and roof complexity.

Solar payback period varies by scheme. On-grid rooftop solar for homes usually pays back in 6–9 years, while industrial/commercial rooftop solar can be 5–7 years because business PLN tariffs are higher. Off-grid solar that replaces a diesel genset is actually the fastest — 2–7 years in areas with high fuel prices (Rp 11,000–18,000/L), because diesel genset operating costs are far higher than PLN. Calculate the exact figure for your case in our on-grid or off-grid calculators.

On-grid solar (rooftop solar) connects to the PLN grid and uses net-metering — surplus daytime panel output is exported to PLN, and at night you still use PLN electricity. Suitable for homes/businesses in cities that already have PLN. Off-grid solar is fully standalone: it uses batteries to store energy for the night and is not connected to PLN at all. Suitable for island villas, telco BTS towers, plantations, farms, or locations without PLN. Off-grid needs higher CapEx because of batteries, but it replaces diesel gensets, so operational savings are higher.

For on-grid rooftop solar: yes, you need to register with PLN per Permen ESDM 2/2024. SPJBTL/Amendment registration and the PLN survey are free (Rp 0). The only paid item is the Operation Worthiness Certificate (SLO) from a Technical Inspection Body — Rp 600 thousand–1.5 million for residential <25 kVA. For off-grid solar: no PLN permission is needed at all since it isn't grid-connected, but obtaining an SLO is still recommended for safety and insurance.

Calculator results are an initial estimate based on Indonesian average assumptions: PSH (Peak Sun Hours) from NASA POWER, a Performance Ratio of 0.80, Q2 2026 PLN tariffs, and Q4 2024–Q1 2025 component market prices. Accuracy is about ±15% of actual figures. Factors that can shift results: roof orientation, shading from trees/buildings, installation quality, and changes in PLN tariffs/regulation. For a precise calculation, conduct a site survey with an AESI/LSPMK-certified EPC.

Yes. Solar panels still generate electricity when it's cloudy — though output drops 10–25% from clear conditions. Our calculator uses annual average irradiance data from NASA POWER that accounts for the rainy & dry seasons, so the annual savings estimate is realistic for Indonesia's tropical climate. Areas like Bali, NTB, and NTT actually have the highest output (PSH ~5.2–5.8 hours/day). High-rainfall areas (Bogor, Manado) remain viable at PSH ~4.2–4.7.

We have a curated contractor directory at /kontraktor — every contractor there must hold DJK/BNSP certification and have active PLN SLO experience. After getting an estimate from the calculator (on-grid or off-grid), you can filter contractors by city and capacity experience, then contact them directly with no broker fee.

Hybrid solar = on-grid + battery backup — still connected to PLN, with a battery to use solar at night and ride through PLN outages. Our on-grid calculator already supports Hybrid mode: enable the 'Add battery' toggle in Step 4, then set the battery capacity (kWh). Q2 2026 price reference (source: public Indonesian EPCs + FOB China benchmark): rack-mount LFP battery Rp 2.85 million/kWh (revised from the outdated Rp 6.5M estimate) + premium hybrid inverter ~Rp 2.5 million/kWp over a regular grid-tie inverter. Total all-in residential hybrid ~Rp 20-26 million/kWp vs pure on-grid ~Rp 13.5 million/kWp. For scenarios with no PLN at all (island villas, remote mining), use the off-grid calculator.