Solar PV Analysis of Honiara, Solomon Islands
Honiara, the capital city of Solomon Islands, is situated in a tropical location that offers consistently favorable conditions for solar energy generation throughout the year. Located at latitude -9.4277 and longitude 159.9494, this equatorial setting experiences minimal seasonal variations in daylight hours, making it an attractive site for solar photovoltaic (PV) installations.
Seasonal Solar Performance
The solar energy output in Honiara remains relatively stable across all seasons, with a notable peak during spring. Here's a breakdown of the expected daily electricity output per kilowatt of installed solar capacity:
- Spring: 6.51 kWh/day
- Autumn: 5.43 kWh/day
- Summer: 5.33 kWh/day
- Winter: 5.24 kWh/day
The spring season stands out as the most productive period for solar energy generation, likely due to clearer skies and optimal sun angles. However, the difference between the highest and lowest producing seasons is relatively small, indicating consistent year-round performance.
Optimal Panel Tilt
For fixed solar panel installations in Honiara, the ideal tilt angle to maximize year-round energy production is 9 degrees facing North. This slight tilt helps optimize the panels' exposure to sunlight throughout the year, taking into account the city's proximity to the equator and the sun's path across the sky.
Environmental Considerations
While Honiara's tropical climate is generally conducive to solar energy production, there are some environmental factors to consider:
1. High Humidity: The tropical climate means high humidity levels, which can potentially lead to condensation on solar panels. To mitigate this, ensure proper sealing and ventilation of electrical components during installation.
2. Heavy Rainfall: Honiara experiences a wet season, typically from November to April. While rain can help clean the panels, heavy downpours might temporarily reduce efficiency. Installing panels at the optimal angle helps with water runoff and self-cleaning.
3. Tropical Storms: The region is prone to tropical storms and cyclones. Robust mounting systems and high-quality, weather-resistant panels are essential to withstand strong winds and heavy rain.
4. Vegetation Growth: The tropical environment promotes rapid vegetation growth. Regular maintenance to prevent shading from nearby trees or plants is crucial for maintaining optimal performance.
By addressing these factors during installation and maintenance, solar PV systems in Honiara can take full advantage of the location's excellent solar potential, providing a reliable and sustainable energy source throughout the year.
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 3 locations across Solomon Islands. This analysis provides insights into each city/location's potential for harnessing solar energy through PV installations.
Link: Solar PV potential in Solomon Islands by location
Solar output per kW of installed solar PV by season in Honiara
Seasonal solar PV output for Latitude: -9.4277, Longitude: 159.9494 (Honiara, Solomon Islands), 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 9° North in Honiara, Solomon Islands
To maximize your solar PV system's energy output in Honiara, Solomon Islands (Lat/Long -9.4277, 159.9494) throughout the year, you should tilt your panels at an angle of 9° 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 Honiara, Solomon Islands
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 Honiara, Solomon Islands. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 9° North tilt angle throughout the year.
| Overall Best Summer Angle | Overall Best Autumn Angle | Overall Best Winter Angle | Overall Best Spring Angle |
|---|---|---|---|
| 7° South in Summer | 15° North in Autumn | 25° North in Winter | 3° 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 Honiara, Solomon Islands
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 Honiara, Solomon Islands.
Our calculation method
- Solar Position:
We determine the Sun's position on the Winter solstice using the location's latitude and solar declination. - Shadow Projection:
We calculate the shadow length cast by panels using trigonometry, considering panel tilt and the Sun's elevation angle. - 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 Honiara, Solomon Islands
The topography around Honiara, the capital city of Solomon Islands, is characterized by a mix of coastal plains and rugged, forested hills. Honiara itself is situated on a narrow coastal strip along the northern coast of Guadalcanal, the largest island in the Solomon Islands archipelago.
Immediately inland from the city, the terrain begins to rise into steep, jungle-covered hills. These hills are part of a mountain range that runs along the spine of Guadalcanal. The elevation increases rapidly as you move away from the coast, with some peaks reaching heights of over 2,000 meters (6,500 feet) further inland.
The coastline near Honiara features a combination of sandy beaches, coral reefs, and mangrove swamps. Rivers and streams flow down from the hills, creating small valleys and floodplains as they approach the sea. The surrounding waters are part of the Solomon Sea, which is known for its deep waters and complex underwater topography.
For large-scale solar PV installations, the most suitable areas would likely be found in the flatter, more open spaces near the coast. The coastal plains around Honiara, particularly to the east and west of the city, offer more level ground and better access to existing infrastructure. These areas would provide easier construction conditions and potentially fewer shading issues from the surrounding hills.
However, it's important to note that suitable land for large solar installations may be limited due to existing development, agricultural use, and the rapid transition from coastal plain to steep hills. Some potential sites might include:
- Cleared areas near the Honiara International Airport, located east of the city center
- Open spaces along the coast west of Honiara, towards White River
- Any available flat land on the outskirts of the city, where the coastal plain is wider
While the hills surrounding Honiara receive ample sunlight, their steep slopes and dense vegetation make them less practical for large-scale solar installations. Smaller, distributed solar systems might be more suitable for these areas.
It's crucial to consider factors such as land ownership, environmental impact, and proximity to the electrical grid when selecting sites for solar PV projects in this region. Additionally, the tropical climate of the Solomon Islands, with its high humidity and potential for severe weather, would need to be taken into account in the design and maintenance of any solar installation.
Citation Guide
Article Details for Citation
Author: Aaron Robinson
Publisher: profileSOLAR.com
First Published: Sunday 29th of September 2024
Last Updated: Monday 21st of July 2025
Tell Us About Your Work
We love seeing how our research helps others! If you've cited this article in your work, we'd be delighted to hear about it. Drop us a line via our Contact Us page or on X, to share where you've used our information - we may feature a link to your work on our site. This helps create a network of valuable resources for others in the solar energy community and helps us understand how our research is contributing to the field. Plus, we occasionally highlight exceptional works that reference our research on our social media channels.
Feeling generous?
Share this with your friends!
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.
