Trashigang, Bhutan, situated in the Northern Sub Tropics at coordinates 27.3293, 91.5534, presents a reasonably favorable location for solar PV energy generation throughout the year. The seasonal variations in electricity output demonstrate a consistent performance across all four meteorological seasons.

Seasonal Solar Performance

Spring emerges as the most productive season, with an average daily output of 4.72 kWh per kW of installed solar capacity. This is closely followed by autumn, yielding 4.61 kWh/day, and summer at 4.48 kWh/day. Winter shows a slight dip in performance but still maintains a respectable 3.98 kWh/day.

The relatively steady output across seasons indicates that Trashigang is well-suited for year-round solar energy production. However, the peak generation period spans from spring through autumn, making these seasons particularly ideal for maximizing solar energy harvest.

Optimal Panel Installation

For fixed panel installations in Trashigang, the ideal tilt angle to maximize year-round solar production is 26 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 Trashigang's location is generally favorable for solar energy production, there are some environmental factors to consider:

• Monsoon season: Bhutan experiences heavy rainfall during the summer monsoon, which could temporarily reduce solar efficiency.
• Mountain shadows: The mountainous terrain might cast shadows on solar panels, particularly during winter when the sun is lower in the sky.

To mitigate these challenges, installers should carefully choose panel locations to minimize shading from nearby mountains. Additionally, using high-quality, water-resistant panels and ensuring proper drainage around the installation can help maintain performance during the rainy season.

In conclusion, Trashigang offers a promising location for solar PV energy generation, with consistent output across seasons and particularly strong performance in spring and autumn. By addressing potential environmental challenges through thoughtful installation practices, solar energy systems in this area can achieve optimal year-round performance.

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 7 locations across Bhutan. This analysis provides insights into each city/location's potential for harnessing solar energy through PV installations.

Link: Solar PV potential in Bhutan by location

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

Seasonal solar PV output for Latitude: 27.3293, Longitude: 91.5534 (Trashigang, Bhutan), 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 26° South in Trashigang, Bhutan

To maximize your solar PV system's energy output in Trashigang, Bhutan (Lat/Long 27.3293, 91.5534) throughout the year, you should tilt your panels at an angle of 26° 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 Trashigang, Bhutan

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 Trashigang, Bhutan. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 26° 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	33° South in Autumn	43° 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 Trashigang, Bhutan

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 Trashigang, Bhutan.

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 Trashigang, Bhutan

Trashigang, situated in eastern Bhutan, is characterized by a diverse and rugged topography typical of the Himalayan region. The town itself is perched on a steep hillside, overlooking the Drangme Chhu river valley. The surrounding landscape is a tapestry of steep mountains, deep valleys, and winding rivers. The area around Trashigang features dramatic elevation changes, with altitudes ranging from about 600 meters in the river valleys to over 4,000 meters in the nearby mountain peaks. This varied terrain creates a mix of microclimates and ecosystems, from subtropical forests in the lower valleys to alpine meadows at higher elevations. The region is crisscrossed by numerous streams and rivers, which have carved deep gorges and valleys over millennia. These waterways, including the Drangme Chhu and its tributaries, have played a crucial role in shaping the local topography. The steep hillsides are often terraced for agriculture, creating a striking visual pattern across the landscape.

Potential for Large-Scale Solar PV

When considering areas nearby Trashigang for large-scale solar photovoltaic (PV) installations, several factors must be taken into account. The ideal location would offer ample sunlight exposure, relatively flat terrain, and accessibility for construction and maintenance. The most suitable areas for solar PV development would likely be found in the wider valley floors and on the gentler slopes of south-facing hillsides. These locations would receive more direct sunlight throughout the day and year, maximizing energy production potential. The broader valleys of the Drangme Chhu and its major tributaries could offer some promising sites, particularly where the terrain flattens out. However, it's important to note that large, flat areas are relatively scarce in this mountainous region. This scarcity might necessitate the use of multiple smaller installations rather than a single large-scale facility. Additionally, any potential sites would need to be carefully evaluated for their environmental impact and potential conflict with agricultural or cultural land uses, which are vital to the local communities. The areas to the south and east of Trashigang, where the terrain becomes slightly less rugged as it transitions towards the Indian plains, might offer more suitable conditions for larger solar installations. These lower-elevation areas generally have more gradual slopes and wider valleys, potentially providing the space and solar exposure needed for effective PV arrays. In conclusion, while the topography around Trashigang presents challenges for large-scale solar PV development, there are opportunities in the broader valleys and on south-facing slopes. Careful site selection and innovative design approaches would be crucial to successfully implementing solar energy projects in this mountainous region.

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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.