Solar PV Analysis of Siraha, Nepal
Siraha, Madhesh, Nepal, situated in the Northern Sub Tropics at coordinates 26.6468, 86.2024, offers a promising location for solar PV energy generation throughout the year. The seasonal electricity output per kW of installed solar panels demonstrates the potential for consistent energy production, with some variations across different times of the year.
Seasonal Solar Performance
Spring emerges as the most productive season, with an impressive output of 5.84 kWh/day per kW installed. Summer and autumn follow closely, generating 4.71 kWh/day and 4.60 kWh/day, respectively. Winter experiences a slight dip in production, yielding 3.71 kWh/day, but still maintains a respectable output.
The location's proximity to the equator contributes to its relatively stable solar potential throughout the year. However, the spring months stand out as the ideal time for solar energy generation, likely due to clearer skies and optimal sun angles.
Optimal Panel Tilt
For fixed panel installations in Siraha, Madhesh, the ideal tilt angle to maximize year-round solar production is 25 degrees facing South. This angle has been calculated to optimize energy capture across all seasons, taking into account the Earth's elliptical orbit and the location's specific latitude.
Environmental Considerations
While Siraha's location is generally favorable for solar energy production, there are some environmental factors to consider:
- Monsoon season: Heavy rainfall and increased cloud cover during the summer monsoon (June to September) may temporarily reduce solar output.
- Dust and pollution: The region can experience dust storms and air pollution, which may accumulate on solar panels and decrease efficiency.
To mitigate these challenges, regular panel cleaning and maintenance should be incorporated into the solar installation plan. Additionally, installing panels at the recommended 25-degree tilt can help with natural cleaning during rainfall. Considering dust-resistant panel coatings and implementing a robust cleaning schedule, especially during drier months, can help maintain optimal energy production throughout the year.
Overall, Siraha's location presents a favorable environment for solar PV energy generation, with consistent output across seasons and particularly high potential during spring months. With proper installation and maintenance practices, solar energy systems in this area can provide a reliable and sustainable power source.
Note: The Northern Sub Tropics extend from 23.5° latitude North up to 35° latitude.
So far, we have conducted calculations to evaluate the solar photovoltaic (PV) potential in 40 locations across Nepal. This analysis provides insights into each city/location's potential for harnessing solar energy through PV installations.
Link: Solar PV potential in Nepal by location
Solar output per kW of installed solar PV by season in Siraha
Seasonal solar PV output for Latitude: 26.6468, Longitude: 86.2024 (Siraha, Nepal), 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 25° South in Siraha, Nepal
To maximize your solar PV system's energy output in Siraha, Nepal (Lat/Long 26.6468, 86.2024) throughout the year, you should tilt your panels at an angle of 25° South 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 Siraha, Nepal
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 Siraha, Nepal. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 25° South tilt angle throughout the year.
| Overall Best Summer Angle | Overall Best Autumn Angle | Overall Best Winter Angle | Overall Best Spring Angle |
|---|---|---|---|
| 11° South in Summer | 32° South in Autumn | 42° South in Winter | 21° South 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 Siraha, Nepal
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 Siraha, Nepal.
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 Siraha, Nepal
The area around Siraha, Nepal, is characterized by relatively flat terrain typical of the Terai region. The Terai is a low-lying plain that stretches across southern Nepal, bordering India. In the vicinity of Siraha, you'll find a landscape dominated by agricultural fields, scattered settlements, and occasional patches of forest.
To the north of Siraha, the land gradually begins to rise as it transitions into the Siwalik Hills, also known as the Churia Range. These are the first foothills of the Himalayas, forming a natural boundary between the Terai and the more mountainous regions of Nepal. However, these hills are still quite some distance from Siraha itself.
The area is crisscrossed by several rivers and streams that flow southward from the hills, creating a network of waterways that are vital for agriculture in the region. These rivers can cause seasonal flooding during the monsoon season, which is an important consideration for any large-scale development projects.
For large-scale solar PV installations, the areas most suited would likely be the open, flat lands of the Terai surrounding Siraha. These areas offer several advantages:
- Ample sunlight throughout the year
- Minimal shadowing from geographical features
- Easy access for construction and maintenance
- Proximity to existing infrastructure and population centers
Specifically, the agricultural lands to the east and west of Siraha could be potential sites for solar farms. These areas are generally flat and open, with few obstructions that might block sunlight. However, it's important to balance the need for solar energy with the preservation of valuable agricultural land, which is crucial for the local economy and food security.
Areas slightly to the north, where the land begins to rise into the Siwalik Hills, might also be considered. While these areas are not as flat, they could potentially offer good solar exposure and might be less likely to conflict with prime agricultural land.
It's worth noting that any large-scale solar project would need to consider factors beyond just topography, including local land use policies, environmental impacts, grid connectivity, and community acceptance. A thorough site-specific assessment would be necessary to determine the most suitable locations for solar PV installations in this region.
Nepal solar PV Stats as a country
Nepal ranks 89th in the world for cumulative solar PV capacity, with 93 total MW's of solar PV installed. This means that 0.10% of Nepal's total energy as a country comes from solar PV (that's 43rd in the world). Each year Nepal is generating 3 Watts from solar PV per capita (Nepal ranks 86th in the world for solar PV Watts generated per capita). [source]
Are there incentives for businesses to install solar in Nepal?
Yes, there are incentives for businesses wanting to install solar energy in Nepal. The Government of Nepal has implemented a number of policies and programs to promote the use of renewable energy sources such as solar power. These include tax exemptions, subsidies, and other financial incentives for businesses that install solar systems. Additionally, the government has established a Renewable Energy Fund which provides grants to support research and development activities related to renewable energy technologies.
Do you have more up to date information than this on incentives towards solar PV projects in Nepal? Please reach out to us and help us keep this information current. Thanks!
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Article Details for Citation
Author: Aaron Robinson
Publisher: profileSOLAR.com
First Published: Saturday 24th of August 2024
Last Updated: Monday 21st of July 2025
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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.
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