The question we get every week from Bali villa owners is some version of: "How many panels do I need?" It sounds simple until you pull apart the variables. The villa has a pool, or it doesn't. Three bedrooms run AC through the night. Or the owner is only there six months a year. The PLN connection is 5,500 VA or 11,000 VA. Each of these details shifts the answer by 30 to 50%, which is why the generic "5 kWp for a 3-bedroom home" you see on most installer websites is nearly useless for Bali villa contexts.
This guide walks through the actual sizing math step by step: how Bali's sun hours translate to panel output, then four villa-size scenarios with real numbers you can use as a working benchmark. We're a solar consultant, not a panel seller, so the goal here is to give you a number you can take into any quote conversation and know whether it holds up. If you'd rather have the math done for your specific villa, there's a calculator link at the bottom, or you can send us your PLN bill on WhatsApp and we'll come back with a sizing estimate the same day.
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TL;DR
- Bali peak sun hours run 4.7 to 5.0 depending on location. The sizing formula: daily kWh divided by (PSH x 0.85) gives you the kWp you need, rounded up to the next module size.
- 2BR no-pool villa: roughly 4 to 5 kWp panels + 5 kW inverter + 10 kWh battery, Rp 90 to 130 million all-in installed.
- 3BR with pool: roughly 7 to 8 kWp + 6 to 8 kW inverter + 12 to 15 kWh battery, Rp 150 to 220 million all-in.
- 4BR with pool: roughly 10 to 12 kWp + 10 kW inverter + 15 to 25 kWh battery, Rp 220 to 320 million all-in.
- Hybrid beats full off-grid for most Bali villas: same blackout protection at 40 to 60% lower cost. Go full off-grid only when PLN doesn't reach you.
- The biggest sizing variable is AC timing: nighttime AC needs battery, daytime AC needs panels. Both have to be planned for separately.
How Bali sun hours translate into panel size
Bali gets 4.7 to 5.0 peak sun hours (PSH) per day on average across the year. PSH is the number of daily hours when sunlight is intense enough to push panels to their rated output. Canggu, Seminyak, and the coastal strip tend to run 4.8 to 5.0. Ubud and Tegallalang drop toward 4.7 due to afternoon cloud buildup off the mountain ridges. Munduk and Bedugul sit lower at 4.0 to 4.4 because of persistent morning cloud cover coming off the lakes. Amed on the east coast is one of the highest-PSH spots on the island at 4.9 to 5.1, sitting in a rain shadow east of Mount Agung.
The starting formula is straightforward:
kWp needed = daily kWh usage / PSH
If your villa uses 30 kWh per day and you're in Canggu (PSH 4.8), that's 30 / 4.8 = 6.25 kWp. We round up to the next module size. A standard 580 Wp panel gives about 0.58 kWp, so 6.25 kWp means 11 panels (6.38 kWp actual).
We then apply a derating factor of about 0.85 for real-world losses: heat (Bali panels run at 50 to 65 degrees C surface temperature vs the 25-degree lab standard, losing 10 to 15% output), inverter conversion (3 to 5%), dust and soiling between cleanings (2 to 3%), and cabling losses. After derating, the formula becomes:
kWp needed = daily kWh / (PSH x 0.85)
Same villa: 30 / (4.8 x 0.85) = 7.35 kWp. Round up to 7.5 or 8 kWp depending on available roof space.
One more adjustment: we always size for the worst month, not the annual average. January and February are Bali's cloudiest months, dropping effective PSH to 3.8 to 4.2 in most areas. A hybrid system can lean on PLN during those stretches, so you don't need to oversize for every worst-case day. A full off-grid system does need that extra buffer built in, which is part of why off-grid costs significantly more for the same daily output.
The daily kWh number is where most quotes go wrong. Many installers estimate from an appliance list instead of your actual bills. Your last six months of PLN statements are far more reliable than any appliance-count calculation. Bills capture your real AC runtime, pool pump, water heater, and every device in the villa, regardless of how long they actually run vs their nameplate rating. Share your bills before you accept a quote.
Four villa-size scenarios with real numbers
These four profiles cover what we size most often in Bali. Equipment costs are before VAT, shipping, and installation labor. Add 35 to 45% for the all-in project total (higher for remote locations or complex roofs).
2BR villa, no pool (Canggu, Sanur, Ubud village area)
Typical daily load: 12 to 18 kWh. Two bedrooms with 1.5 PK inverter-type AC running 8 to 10 hours overnight, a refrigerator, lights, water pump, and basic electronics.
| Component | Spec | Equipment cost |
|---|---|---|
| Panels | 5 kWp (nine 580 Wp modules, Jinko or Trina) | Rp 18 to 22 million |
| Inverter | 5 kW hybrid, 1-phase (Growatt or Luxpower) | Rp 16 to 20 million |
| Battery | 10 kWh LiFePO4 (two Pylontech 5.12 kWh modules) | Rp 33 to 38 million |
| Equipment total | Rp 55 to 70 million | |
| All-in installed | Add 35-45% for shipping + labor + balance of system | Rp 90 to 130 million |
3BR villa with pool (Pererenan, Kerobokan, Seminyak, Ubud fringe)
Typical daily load: 22 to 32 kWh. Three AC units, pool pump at 1.5 kW for 5 hours, refrigerator, washing machine a few times a week, water pump, lights.
| Component | Spec | Equipment cost |
|---|---|---|
| Panels | 7 kWp (twelve 580 Wp modules) | Rp 26 to 31 million |
| Inverter | 7 kW hybrid, 1-phase (Luxpower SNA or Deye SUN-7K) | Rp 24 to 30 million |
| Battery | 13 kWh LiFePO4 (two to three Pylontech modules) | Rp 43 to 55 million |
| Equipment total | Rp 90 to 130 million | |
| All-in installed | Rp 150 to 220 million |
4BR villa with pool (Seminyak, Uluwatu, larger Ubud compounds, Canggu estate)
Typical daily load: 30 to 50 kWh. Four to five AC units with some running 14 to 16 hours, pool pump at 1.5 to 2 kW for 6 hours, well pump cycling, two refrigerators, dishwasher, and heavier electronics load.
| Component | Spec | Equipment cost |
|---|---|---|
| Panels | 11 kWp (nineteen 580 Wp modules) | Rp 40 to 48 million |
| Inverter | 10 kW hybrid, 3-phase (Deye SUN-10K; 3-phase is correct above 8 kWp) | Rp 42 to 50 million |
| Battery | 20 kWh LiFePO4 (four Pylontech modules or two HinaESS PowerGem Plus 14.3 kWh) | Rp 65 to 90 million |
| Equipment total | Rp 145 to 190 million | |
| All-in installed | Rp 220 to 320 million |
6BR luxury villa (Uluwatu cliff, large Canggu compound, Bukit estate)
Typical daily load: 60 to 100 kWh. Six to eight AC units including a master suite running continuously, large pool with heating, commercial-style kitchen, gym or sauna, garden lighting.
| Component | Spec | Equipment cost |
|---|---|---|
| Panels | 20 to 25 kWp (35 to 44 modules, split across roof faces) | Rp 72 to 95 million |
| Inverter | 20 to 25 kW, 3-phase (Deye 25 kW HV or paired Sungrow 12 kW for redundancy) | Rp 55 to 75 million |
| Battery | 35 to 50 kWh LiFePO4 (seven to ten Pylontech modules or four PowerGem Plus) | Rp 115 to 180 million |
| Equipment total | Rp 250 to 380 million | |
| All-in installed | Rp 380 to 600 million |
These ranges shift 15 to 20% based on brand selection, villa location, and roof complexity. Remote villas in Sidemen, Munduk, or north of Amed add Rp 8 to 15 million for crew transport and extended cabling runs.
Hybrid vs full off-grid: get this right before you size
The architecture choice changes your battery sizing, your project cost, and your contingency options. It's worth settling before you go further on component specs.
For most villas in the Canggu, Seminyak, Kerobokan, Sanur, and central Ubud areas, hybrid is the correct answer. Solar and battery cover your daytime load and nighttime AC. PLN sits as a quiet backup for the occasional long rainy stretch in January or February. You don't notice the transition.
Full off-grid makes sense in two real situations: PLN genuinely doesn't reach your villa (common in Sidemen valley, deep Uluwatu cliff edges, Munduk interior, and some coastal strips north of Amed town), or PLN is technically available but fails for hours every day and you wouldn't trust it as a fallback regardless.
The cost difference is real. A 4BR villa in hybrid configuration typically lands at Rp 250 to 320 million all-in. That same villa in full off-grid, sized to handle a 3-day cloudy stretch with no PLN top-up, typically runs Rp 360 to 450 million, because you need 1.5 to 2x the battery capacity and a slightly larger inverter to handle surge loads without grid support.
For most Bali villa owners in areas where PLN reaches them, that extra Rp 100 to 130 million doesn't buy anything you'd notice in daily experience. Use PLN as the backstop it's designed to be. That's the whole point of hybrid.
What shifts your number more than bedroom count
Bedroom count is a proxy for load. These four variables shift the actual sizing more directly.
AC usage timing. Bali villa AC load splits roughly 30 to 40% daytime (living rooms, office areas during work hours) and 60 to 70% nighttime (bedrooms, 9 PM to 7 AM). Panels carry daytime AC well. Nighttime AC has to come from battery. A villa where four AC units run only at night needs substantially more battery relative to panels than a villa with a daytime coworking setup running AC from 9 AM to 6 PM. The pattern matters as much as the count.
Pool pump size and runtime. A 1 kW pump running 5 hours adds 5 kWh/day. A 2 kW pump running 8 hours adds 16 kWh/day. At Bali PSH of 4.8, that 16 kWh from the pump alone requires nearly 4 extra kWp of panels just for that load. Variable-speed pumps cut average draw to 0.8 to 1.2 kW, saving 6 to 10 kWh per day without changing filtration performance. If you haven't switched to a variable-speed pump yet, do it before finalizing your panel count. It materially changes the sizing.
Roof shading. A mature frangipani or a neighboring villa wall shading 15% of your roof during peak hours can cut string inverter production by 20 to 30%. If shading is present and can't be removed (heritage tree rules are common in Ubud, neighbor walls are common in Seminyak), mention it early. We adjust the array layout or recommend microinverters or DC optimizers rather than a string configuration.
Roof orientation. The ideal setup in Bali (8.4 degrees south latitude) is panels facing true north, tilted 8 to 12 degrees. East or west-facing panels produce about 90 to 93% of north-optimal output, which is acceptable in most cases. South-facing panels are a significant error, dropping to 85 to 88%, and happen when crews trained in the northern hemisphere default to south out of muscle memory. Confirm the orientation during the site survey.
When this doesn't fit your villa
We'd rather tell you up front than have you go through a full quote process that leads nowhere.
Heavy unavoidable shading. If a 30-meter banyan tree shades most of your roof for 4 to 5 peak hours and you can't or won't trim it, the economics shift hard. You'd need significantly more panels to hit your output target, but the roof probably doesn't have the area to support them.
Roof that needs replacing first. We won't spec 20 panels onto terracotta tile showing structural movement or needing re-bedding within 3 to 5 years. Fix the roof first. Solar on a failing roof means disassembly and reinstall later, which costs more than waiting.
Selling the villa within 2 to 3 years. Solar adds resale value in Bali, but not enough to recover a Rp 200 million install cost in 2 years. The math only holds when you're committed to the property for 5 or more years.
Bills below Rp 1.2 million per month. At that level, payback stretches beyond 10 years. The capital is almost certainly better deployed elsewhere unless there's a specific non-financial reason to install (off-grid necessity, reliability for short-term rental guests, or a specific eco-positioning goal).
Ready to size your villa?
If you want a precise number rather than a benchmark range, the quickest path is the calculator below or a WhatsApp message with your villa details. Send us your location, bedroom count, whether you have a pool, and your last 3 months of PLN bills. We'll come back with a real sizing estimate and equipment cost range within one business day. No commitment required, and if the numbers don't work for your situation, we'll tell you that plainly.
Frequently asked questions
A 3BR villa with a pool and AC across all rooms typically uses 22 to 32 kWh per day. That works out to about 7 to 8 kWp of panels, with a 6 to 8 kW hybrid inverter and 12 to 15 kWh of LiFePO4 battery. Equipment cost before VAT and labor runs roughly Rp 90 to 130 million. Add 35 to 45% for shipping, installation, and commissioning.
