Before anyone spends 65 million rupiah on panels, I often point them at a much smaller number first. Electric water heating quietly takes 15–25% of a typical villa's PLN bill — those instant heaters in every bathroom are 2,000-watt appliances running on the most expensive tariff. Bali sits eight degrees south of the equator; heating water is what our sun does best. A rooftop solar water heater is the simplest renewable device we install: no inverter, no electronics, no PLN paperwork, and payback typically in five to seven years. It is where I tell most budget-conscious clients to start.
What's Included
Tank & Collector Sizing
150 L suits a couple, 200 L a family of four, 300 L a villa with guest bathrooms. We count bathrooms and habits rather than guessing — an undersized tank means cold showers, an oversized one wastes capital.
Thermosiphon Systems
The classic no-moving-parts setup: collector below tank, water circulates by physics alone. Nothing to break, nothing to power. Our default recommendation for most roofs.
Pressurised & Pumped Systems
For villas with pressure pumps and rain showers, we install pressurised tanks or pumped circulation that hold mains pressure at the tap — no weak hot-water dribble.
Backup Element & Controls
Every system includes an electric backup element on a thermostat and timer for the occasional week of solid rain — it runs only when the sun genuinely has not done the job.
What a Solar Water Heating Add-On Saves in Bali
Run the numbers on a family villa: four people showering daily uses roughly 5–7 kWh of electric heating per day, which at PLN's R-2 tariff of IDR 1,699.53 per kWh is IDR 250,000–350,000 a month, more if guests visit. A correctly sized solar water heater takes that to nearly zero for eight to nine months of the year and cuts it sharply even through the wet season. On a 21 million rupiah system, payback lands at roughly five to seven years — close to the four to six years of a well-sized PV system, for about a third of the outlay, as the maths in our solar cost and payback article shows.
Water heaters also combine well with photovoltaics: if you are planning a full panel installation, taking water heating off the electrical load first means you can buy a smaller, cheaper array. We model both together in our system design service. Existing heater playing up instead? We service and repair most rooftop brands too — ask via contact.
PV-Driven Water Heating: Put Your Solar Surplus Into the Tank
Since the 2024 PLN rule change, surplus power a new system exports to the grid no longer reduces your bill. On a villa with a rooftop PV system, the cheapest place to store that midday surplus is hot water. We wire an existing or new electric storage tank to run from the PV system in the sunny hours — on a simple timer set to 10:00–14:00, or on a diverter that sends only genuine surplus to the heating element — so the tank is full before evening showers and the instant heaters stay off.
For larger villas we pair the PV system with a heat pump water heater instead: it makes the same hot water with roughly a third of the electricity of a plain element, which leaves more of your array for air conditioning and the pool pump. The choice between a timer, a diverter and a heat pump comes out of the load calculation in our system design service, and all three work with the rooftop PV systems we install. If you have no PV yet, the 150–300 litre rooftop add-on priced below is the simplest standalone option.
How We Work
Count bathrooms on WhatsApp
Tell us bathrooms, household size and whether you have a pressure pump. Photos of the roof help us pick mounting.
Same-day recommendation
We reply with the right tank size, thermosiphon or pressurised, and a fixed installed price.
Installation in one day
Roof mounting, plumbing tie-in, backup element wiring and insulation — a standard install is done between morning and afternoon coffee.
Hot water that evening
We commission the system, set the backup timer, and you shower on sunshine the same night. Tank warranty is five years.
What It Costs
Installed prices: 150 L from IDR 14,500,000, 200 L from IDR 21,000,000, 300 L from IDR 29,000,000 — including mounting, plumbing connection, backup element and commissioning. Pressurised systems add roughly 20%. Full tables on the pricing page.
Frequently Asked Questions
Will I have hot water in the rainy season?
How much maintenance does a solar water heater need?
Is my roof strong enough for the tank?
Solar water heater or heat pump — which is better?
Solar Coverage Across Bali
Shower on Sunshine
Tell us how many bathrooms you have — we reply the same day with the right system size and a fixed installed price.
Get a Water Heater Quote