East Kalimantan · Indonesia · 0.13° N · 117.49° E
Solar position in Bontang
Sun position, daylight and the best solar panel angle for Bontang — computed for 0.13° N, 117.49° E, 10 m above sea level.
The sun right now
Sun in Bontang today
Sunday, 25 October 2026 · local time UTC+8
| Event | Time | Direction / height |
|---|---|---|
| Astronomical dawn | 04:40 | sun 18° below horizon |
| Nautical dawn | 05:05 | 12° below |
| Civil dawn | 05:29 | 6° below |
| Sunrise | 05:50 | 102° ESE |
| Golden hour ends | 06:18 | sun 6° up |
| Solar noon | 11:54 | 77.8° high |
| Golden hour starts | 17:29 | sun 6° up |
| Sunset | 17:57 | 258° WSW |
| Civil dusk | 18:18 | 6° below |
| Nautical dusk | 18:43 | 12° below |
| Astronomical dusk | 19:07 | 18° below |
| Day length | 12 h 07 min | |
Sun path diagram for Bontang
Where the sun stands in the sky: the centre is straight overhead, the outer ring is the horizon. Numbers mark local clock hours.
- June solstice
- Equinox
- December solstice
- Today
On the June solstice the sun reaches 66.7° at solar noon in Bontang; on the December solstice only 66.4°. Sunrise swings from 67° ENE in June to 113° ESE in December — a 47° arc along the horizon.
Sunrise, sunset and sun height by month
Values for the 21st of each month, local clock time including daylight saving time.
| Month | Sunrise | Solar noon | Sunset | Day length | Noon elevation |
|---|---|---|---|---|---|
| January | 06:17 | 12:21 | 18:24 | 12 h 07 min | 70.0° |
| February | 06:20 | 12:23 | 18:26 | 12 h 07 min | 79.3° |
| March | 06:14 | 12:17 | 18:20 | 12 h 07 min | 89.9° |
| April | 06:05 | 12:08 | 18:12 | 12 h 07 min | 78.3° |
| May | 06:02 | 12:06 | 18:10 | 12 h 08 min | 70.0° |
| June | 06:07 | 12:11 | 18:15 | 12 h 08 min | 66.7° |
| July | 06:12 | 12:16 | 18:20 | 12 h 08 min | 69.7° |
| August | 06:09 | 12:13 | 18:16 | 12 h 07 min | 78.0° |
| September | 06:00 | 12:03 | 18:06 | 12 h 06 min | 89.4° |
| October | 05:51 | 11:54 | 17:57 | 12 h 06 min | 79.2° |
| November | 05:52 | 11:55 | 17:59 | 12 h 07 min | 70.0° |
| December | 06:04 | 12:07 | 18:11 | 12 h 07 min | 66.4° |
A year of daylight in Bontang
Each column is one day of 2026. Bright: sun above the horizon; soft: civil twilight; line: solar noon. Steps are daylight saving time changes.
Best solar panel angle in Bontang
Fixed array facing south (azimuth 180°). Energy per kWp from NASA POWER monthly climate, including clouds, temperature and snow reflection.
0°collects the most energy over a year: 1412 kWh per kWp.
0°gives the most in the darkest month — the one an off-grid system is sized for.
- Yearly energy
- Worst-month energy
| Tilt | kWh/kWp per year | Share of best year | June kWh/kWp/day | Best ÷ worst month |
|---|---|---|---|---|
| 0° year-round best off-grid best = latitude | 1412 | 100% | 3.55 | 1.2× |
| 15° | 1370 | 97% | 3.12 | 1.3× |
| 30° | 1256 | 89% | 2.53 | 1.6× |
| 45° | 1078 | 76% | 1.83 | 2.0× |
| 60° | 855 | 61% | 1.16 | 2.9× |
| 70° | 714 | 51% | 1.03 | 2.9× |
| 90° | 490 | 35% | 0.93 | 2.3× |
A fixed array in Bontang produces the most over a year at 0°. The design month for an off-grid system is June: at 0° it makes 3.55 kWh per kWp a day, and costs 0% of the yearly total. Why steep panels win winter.
Off-grid solar in Bontang at 70°
Daily energy of 1 kWp by month. Bars: panels at 70°. Line: panels at 0° (year-round best).
| Month | Sun hours, flat | Sun hours at 70° | kWh/kWp/day at 70° | at 0° | Mean temp. |
|---|---|---|---|---|---|
| January | 4.64 | 3.58 | 2.91 | 3.67 | 26.3 °C |
| February | 5.14 | 3.39 | 2.75 | 4.08 | 26.3 °C |
| March | 5.22 | 2.67 | 2.15 | 4.15 | 26.6 °C |
| April | 5.15 | 1.75 | 1.38 | 4.08 | 26.8 °C |
| May | 4.85 | 1.34 | 1.04 | 3.84 | 27.0 °C |
| June | 4.49 | 1.33 | 1.03 | 3.55 | 26.4 °C |
| July | 4.67 | 1.34 | 1.04 | 3.70 | 26.1 °C |
| August | 5.00 | 1.49 | 1.17 | 3.97 | 26.2 °C |
| September | 5.07 | 2.23 | 1.78 | 4.03 | 26.5 °C |
| October | 4.94 | 2.99 | 2.41 | 3.92 | 26.8 °C |
| November | 4.77 | 3.52 | 2.86 | 3.77 | 26.8 °C |
| December | 4.62 | 3.70 | 3.01 | 3.65 | 26.6 °C |
| Year | 4.88 avg | 2.44 avg | 714 kWh | 1412 kWh |
Sizing example. To run a 1 kWh-per-day load through June on LiFePO4 batteries (charge controller, battery and inverter losses included) you need about 1,140 Wp of panels at 70°, versus 330 Wp at 0°. Here the lower tilt is the better winter choice — the sun stays high enough. Size your own system.
Row spacing in Bontang
Distance between rows of 2 m long panels (slope length) so that no row shades the next between 10:00 and 14:00 solar time on the winter solstice.
1.6 mrow pitch at 70°
2.0 mrow pitch at 0°
How Bontang compares in Indonesia
Against the other 446 places in Indonesia with climate data, for a fixed array at its best angle.
360thof 447 places in Indonesia for sunshine, shared: 4.88 peak sun hours a day on flat ground.
−6%solar energy a year compared with the average place in Indonesia: 1,412 against 1,498 kWh per kWp.
−21 mindaylight on the longest day, compared with Jakarta: 12 h 08 min against 12 h 29 min.
0°best year-round tilt here; across Indonesia it runs from 0° in Batam to 12° in Kupang.
Of the 447 places in Indonesia, Lewoleba gets the most sun (5.95 peak sun hours a day) and Kuala Tungkal the least (4.48); Bontang ranks joint 360th. In its darkest month, June, 1 kWp of off-grid panels at 70° makes 1.03 kWh a day here, against 1.26 kWh on average in Indonesia. The shortest day lasts 12 h 07 min, +21 min compared with Jakarta.
Solar forecast for Bontang, next 48 hours
Expected output of 1 kWp at 70°, computed from the ICON-EU weather model of the Deutscher Wetterdienst (DWD), Europe.
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Questions about the sun in Bontang
What is the best solar panel angle in Bontang?
What time is sunrise and sunset in Bontang today?
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Places near Bontang
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A free, live card for Bontang: where the sun is right now on today's path, a countdown to sunset or sunrise, the daylight change, the moon phase at night and the best panel angle.
Sun positions: NREL Solar Position Algorithm. Climate: NASA POWER monthly climatology (NASA Langley Research Center). Forecast: Deutscher Wetterdienst, ICON-EU (CC BY 4.0), processed. Places: GeoNames (CC BY 4.0). Time zones: IANA. Sources and licences.