Jombang, West Java, Indonesia presents a highly favorable location for year-round solar PV energy generation. Located in the tropical zone, this area benefits from consistent sunlight throughout most of the year, with seasonal variations typically characterized by wet and dry periods rather than the traditional four seasons experienced in temperate climates.

Solar Energy Production Potential

The solar energy output data for Jombang demonstrates excellent year-round performance. Spring delivers the highest production at 5.42kWh per day per kW of installed solar capacity, closely followed by autumn at 5.35kWh per day. Winter maintains strong performance at 5.04kWh per day, while summer shows the lowest output at 4.71kWh per day per kW installed. The relatively small variation between seasons - only about 0.71kWh difference between the highest and lowest performing seasons - indicates remarkably consistent solar conditions throughout the year. This consistency makes Jombang an ideal location for solar installations, as energy production remains reliable regardless of the time of year. For optimal performance, solar panels should be installed at a fixed tilt angle of 7 degrees facing north. This angle has been calculated to maximize total year-round solar production by accounting for the sun's path throughout the year and weighting the optimal daily angles by solar irradiance potential.

Environmental and Weather Challenges

Despite the excellent solar potential, several local factors could impact solar energy production in Jombang and require careful consideration during installation planning. The tropical climate brings significant humidity levels year-round, which can lead to moisture-related issues. High humidity promotes the growth of mold, algae, and other organic matter on solar panel surfaces, reducing their efficiency over time. Additionally, the combination of heat and humidity can accelerate corrosion of metal components and degrade electrical connections more rapidly than in drier climates. Tropical weather patterns typically include intense rainfall during wet seasons, which can create multiple challenges. Heavy rains may cause temporary shading from thick cloud cover, though this is already reflected in the seasonal output variations. More concerning is the potential for water infiltration into electrical systems and the accumulation of debris washed onto panel surfaces during storms. The consistent warm temperatures, while beneficial for year-round operation, can also reduce panel efficiency. Solar panels typically lose efficiency as temperatures rise above their optimal operating range, and tropical locations often experience sustained high temperatures that can impact overall performance.

Preventative Installation Measures

Several installation strategies can help mitigate these tropical challenges and ensure optimal energy production:

• Install panels with adequate ventilation spacing underneath to promote air circulation and cooling
• Use high-quality, corrosion-resistant mounting hardware specifically rated for marine or tropical environments
• Ensure all electrical connections are properly sealed with weatherproof enclosures and use cables rated for high humidity conditions
• Design drainage systems to prevent water pooling around installations
• Plan for regular cleaning and maintenance schedules to remove organic growth and debris

Proper installation techniques should include elevated mounting systems that allow airflow beneath panels, helping to reduce operating temperatures. Using materials with appropriate UV resistance ratings is also crucial, as tropical locations receive intense solar radiation that can degrade inferior materials more quickly. Regular maintenance becomes particularly important in tropical climates. Establishing a routine cleaning schedule to remove accumulated dirt, organic growth, and debris will help maintain optimal energy production. Professional inspections should focus on checking seals, electrical connections, and signs of corrosion or degradation. Overall, while Jombang presents some typical tropical challenges for solar installations, these can be effectively managed through proper planning, quality materials, and regular maintenance. The location's excellent and consistent solar resource makes it well worth implementing these preventative measures to ensure long-term, reliable solar energy production.

Note: The Tropics are located between 23.5° North and -23.5° South of the equator.

So far, we have conducted calculations to evaluate the solar photovoltaic (PV) potential in 151 locations across Indonesia. This analysis provides insights into each city/location's potential for harnessing solar energy through PV installations.

Link: Solar PV potential in Indonesia by location

Solar output per kW of installed solar PV by season in Jombang

Seasonal solar PV output for Latitude: -6.2928, Longitude: 106.681 (Jombang, Indonesia), based on our analysis of 8760 hourly intervals of solar and meteorological data (one whole year) retrieved for that set of coordinates/location from NASA POWER (The Prediction of Worldwide Energy Resources) API:

 

Ideally tilt fixed solar panels 7° North in Jombang, Indonesia

To maximize your solar PV system's energy output in Jombang, Indonesia (Lat/Long -6.2928, 106.681) throughout the year, you should tilt your panels at an angle of 7° North for fixed panel installations.

As the Earth revolves around the Sun each year, the maximum angle of elevation of the Sun varies by +/- 23.45 degrees from its equinox elevation angle for a particular latitude. Finding the exact optimal angle to maximise solar PV production throughout the year can be challenging, but with careful consideration of historical solar energy and meteorological data for a certain location, it can be done precisely.

We use our own calculation, which incorporates NASA solar and meteorological data for the exact Lat/Long coordinates, to determine the ideal tilt angle of a solar panel that will yield maximum annual solar output. We calculate the optimal angle for each day of the year, taking into account its contribution to the yearly total PV potential at that specific location.

Seasonally adjusted solar panel tilt angles for Jombang, Indonesia

If you can adjust the tilt angle of your solar PV panels, please refer to the seasonal tilt angles below for optimal solar energy production in Jombang, Indonesia. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 7° North tilt angle throughout the year.

Overall Best Summer Angle	Overall Best Autumn Angle	Overall Best Winter Angle	Overall Best Spring Angle
10° South in Summer	13° North in Autumn	22° North in Winter	1° North in Spring

Our recommendations take into account more than just latitude and Earth's position in its elliptical orbit around the Sun. We also incorporate historical solar and meteorological data from NASA's Prediction of Worldwide Energy Resources (POWER) API to assign a weight to each ideal angle for each day based on its historical contribution to overall solar PV potential during a specific season.

This approach allows us to provide much more accurate recommendations than relying solely on latitude, as it considers unique weather conditions in different locations sharing the same latitude worldwide.

Calculate solar panel row spacing in Jombang, Indonesia

We've added a feature to calculate minimum solar panel row spacing by location. Enter your panel size and orientation below to get the minimum spacing in Jombang, Indonesia.

Our calculation method

1. Solar Position:
   We determine the Sun's position on the Winter solstice using the location's latitude and solar declination.
2. Shadow Projection:
   We calculate the shadow length cast by panels using trigonometry, considering panel tilt and the Sun's elevation angle.
3. Minimum Spacing:
   We add the shadow length to the horizontal space occupied by tilted panels.

This approach ensures maximum space efficiency while avoiding shading during critical times, as the Winter solstice represents the worst-case scenario for shadow length.

Topography for solar PV around Jombang, Indonesia

Topographical Features Around Jombang

The area surrounding Jombang in East Java, Indonesia is characterized by relatively flat to gently rolling terrain that forms part of the broader Brantas River valley system. This region sits within the fertile alluvial plains that stretch across much of northern East Java, creating a landscape dominated by agricultural fields, small settlements, and scattered industrial facilities. The elevation in this area remains fairly consistent, with most land sitting between 50 to 150 meters above sea level.

The topography is heavily influenced by the presence of several river systems, particularly the Brantas River and its tributaries, which have carved gentle valleys and deposited rich sediments across the landscape over millennia. These waterways create a network of slightly lower-lying areas interspersed with modest ridges and elevated plateaus. The overall terrain can be described as undulating rather than dramatically varied, with slopes that are generally gradual and manageable for development purposes.

To the south of Jombang, the land begins to rise more noticeably as it approaches the foothills of the volcanic mountain ranges that dominate southern East Java. However, the immediate vicinity remains predominantly flat, making it well-suited for various forms of development and infrastructure projects.

Optimal Areas for Large-Scale Solar Development

The most promising locations for large-scale solar photovoltaic installations around Jombang would be the extensive flat agricultural areas to the north and northeast of the city center. These areas offer several key advantages including minimal topographical obstacles, existing road access for construction and maintenance, and relatively sparse population density that could facilitate land acquisition.

The gently sloping terrain found approximately 10-15 kilometers northwest of Jombang presents particularly attractive conditions for solar development. This area combines favorable topography with proximity to existing electrical infrastructure while maintaining sufficient distance from dense residential areas. The slight natural slopes in this region would actually benefit solar panel installations by providing optimal orientation possibilities without requiring extensive earthwork or grading.

Areas to the east of Jombang, where the landscape transitions into broader agricultural plains, also show strong potential for solar development. These locations benefit from expansive open spaces with minimal shading from trees or structures, consistent terrain that would simplify installation logistics, and good accessibility via the regional road network.

The flatter agricultural zones extending toward the coast would be less ideal due to their importance for rice cultivation and food security, as well as potential issues with seasonal flooding during monsoon periods. Similarly, areas closer to the southern hills should be avoided due to increased terrain complexity and potential shading issues from elevated landforms.

Indonesia solar PV Stats as a country

Indonesia ranks 71st in the world for cumulative solar PV capacity, with 211 total MW's of solar PV installed. Each year Indonesia is generating 1 Watts from solar PV per capita (Indonesia ranks 88th in the world for solar PV Watts generated per capita). [source]

Are there incentives for businesses to install solar in Indonesia?

Yes, there are several incentives for businesses wanting to install solar energy in Indonesia. The Indonesian government has implemented a number of policies and programs to encourage the adoption of renewable energy sources such as solar power. These include tax exemptions, subsidies, feed-in tariffs, and other financial incentives. Additionally, the government has established a Renewable Energy Fund which provides grants for research and development projects related to renewable energy technologies.

Do you have more up to date information than this on incentives towards solar PV projects in Indonesia? Please reach out to us and help us keep this information current. Thanks!

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Compare this location to others worldwide for solar PV potential

The solar PV analyses available on our website, including this one, are offered as a free service to the global community. Our aim is to provide education and aid informed decision-making regarding solar PV installations.

However, please note that these analyses are general guidance and may not meet specific project requirements. For in-depth, tailored forecasts and analysis crucial for feasibility studies or when pursuing maximum ROI from your solar projects, feel free to contact us; we offer comprehensive consulting services expressly for this purpose.

Helping you assess viability of solar PV for your site

Calculate Your Optimal Solar Panel Tilt Angle: A Comprehensive Guide

Enhance your solar panel's performance with our in-depth guide. Determine the best tilt angle using hard data, debunk common misunderstandings, and gain insight into how your specific location affects solar energy production.