Most homeowners ask "how many kWp do I need?" before they've ever opened a PLN bill. But that bill is the most honest data source you have on your home's electricity habits. Without reading it first, the kWp recommendation can land way off. Either too small and you don't get the energy control you wanted, or too big and the investment doesn't pay back at the right speed.
The energy control we're really chasing with solar isn't just lower bills this month. The goal: less reliance on a single provider whose tariff can rise any time without your input. To get there, you need accurate consumption numbers, and those live on your PLN bill, not in an installer's rough estimate.
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TL;DR
- Two crucial columns: total kWh consumed and tariff group / VA. Those two alone get you to a starting estimate.
- Fixed charges aren't consumption: PLN's monthly base charge (abodemen) doesn't reflect what you used. Don't include it in the kWh math.
- Tariff per kWh affects payback: R-1 2200 VA (Rp 1,444/kWh) vs R-1 3500 VA (Rp 1,699/kWh) is a small gap with a real effect on payback period.
- Average 6 months, not just the most recent month: a single bill can be an outlier from heavier AC use or guests staying over.
- Daytime vs nighttime profile matters for battery sizing, but your bill doesn't show it. Track that yourself.
- Upgrading VA changes tariff: planning 2200 to 3500 VA? Check the tariff impact before finalizing system size.
Which PLN bill columns to read
Whether physical or digital (PLN Mobile app), the structure is the same:
Tariff group and connection rating. Example: "R-1/TR 2200 VA". "R-1" = small residential, "TR" = low voltage, "2200 VA" = connection capacity you pay the base charge on. This sets the per-kWh tariff.
Total kWh consumed. The most important column. Total electricity you used in one month, the basis for sizing.
Usage cost. Total kWh x tariff per kWh. Verify it: at R-1 2200 VA using 830 kWh, usage cost is about Rp 1,198,520 (830 x Rp 1,444).
Base charge (abodemen). Fixed monthly charge regardless of usage. For 2200 VA, Rp 30,000 to Rp 40,000. Doesn't reflect consumption. Skip in sizing math.
VAT and stamp duty. 11% VAT and Rp 10,000 stamp duty (above the threshold). Not consumption, but show up in the final total.
For sizing, you need two columns: total kWh consumed and tariff group + VA.
Rough sizing from the bill, real example
Concrete example: 2200 VA home, April 2026 bill of Rp 1,230,000.
Step 1: peel off the fixed charges. R-1 2200 VA base charge is around Rp 33,000. VAT and stamp duty come to about Rp 135,000. Pure usage cost: roughly Rp 1,062,000.
Step 2: calculate kWh. Rp 1,062,000 / Rp 1,444 (R-1 2200 VA tariff) = about 735 kWh consumed that month.
Step 3: estimate solar size. A 1 kWp panel in Indonesia averages 100 to 130 kWh per month (depending on city irradiance and roof orientation). Cover 50% target: 735 x 50% = 368 kWh from solar, needing about 3 kWp. Cover 80% target: 590 kWh, needing about 5 kWp.
Step 4: check roof capacity. 1 kWp needs about 5 to 6 m2 of usable roof area. A 3 kWp system needs 15 to 18 m2. A 5 kWp system needs 25 to 30 m2.
This is a starting estimate before the site survey. The number can shift after the installer checks roof orientation, shading, and your daytime vs nighttime usage profile.
Use the calculator for numbers specific to your home
R-1, R-2, R-3 tariffs and what they mean for payback
PLN residential tariffs come in groups that affect payback math:
R-1 TR 900 VA: Rp 1,352/kWh. Rare in newer homes, most migrated to 1300 VA.
R-1 TR 1300 VA and 2200 VA: Rp 1,444/kWh. Most common group. A 3 kWp system with a Rp 1.2 million bill pays back in 6 to 8 years.
R-1 TR 3500 VA and 5500 VA: Rp 1,699.53/kWh. Higher tariff means each self-produced kWh is worth more, so payback runs 1 to 2 years faster than lower R-1.
R-2 TR 6600 VA to 14000 VA: Rp 1,699.53/kWh. Same as upper R-1 but larger base charge. Heavy usage, solar very justified.
R-3 TR over 14000 VA: Higher tariff, usually large homes or commercial. Solar highly justified but sizing needs more detail.
A simple table:
| Group | VA | Tariff/kWh | Notes |
|---|---|---|---|
| R-1 | 900 VA | Rp 1,352 | Rare in newer homes |
| R-1 | 1300-2200 VA | Rp 1,444 | Most common |
| R-1 | 3500-5500 VA | Rp 1,699 | Faster solar payback |
| R-2 | 6600-14000 VA | Rp 1,699 | Larger base charge |
If you're planning to upgrade VA at the same time as installing solar (say, 2200 to 3500 VA for an extra AC or an EV charger), calculate the impact on the base charge and per-kWh tariff before finalizing system size.
When this approach doesn't fit
The "read your bill first" approach isn't great if you've just moved into a new home and don't have 3 to 6 months of bill history. In that case, a load analysis based on appliances and run-time is more relevant. Ask the installer to estimate consumption from your appliance inventory rather than relying on historical bills that might reflect a previous tenant with very different habits.
Frequently asked questions
Two columns: total monthly kWh consumed, and the tariff group plus connection rating in VA. Those two get you to a starting kWp estimate. For more accuracy, average your last 6 months of bills, not just the most recent one.
