Located in the tropical region of Thailand, Chiang Mai offers an optimal environment for solar power generation due to its year-round abundant sunlight. The average energy production per kilowatt of installed solar panels varies across seasons, with Spring being the most productive at 6.08 kWh/day. This is followed by Summer and Winter yielding 5.35 kWh/day and 5.30 kWh/day respectively, while Autumn produces slightly less at 4.84 kWh/day.
Chiang Mai's geographic coordinates (latitude: 18.7929, longitude: 99.0004) also contribute to its suitability for solar power generation as it lies within the Tropics where daylight hours remain relatively consistent throughout the year unlike temperate regions that experience significant seasonal variations.
For fixed panel installations in Chiang Mai, a tilt angle of 18 degrees towards South is recommended for optimal sun exposure throughout the year.
The city's climate characterized by warm temperatures and high humidity levels does not pose any significant impediments to solar power production; however, it should be noted that during monsoon season (May to October), prolonged periods of cloud cover may slightly reduce energy yield from solar panels.
To mitigate this potential issue and maximize energy production throughout the year, careful site selection away from shadow-casting structures or vegetation can be beneficial when installing panels in Chiang Mai.
Overall, given these factors along with its favorable climatic conditions and geographical location within the tropics zone; Chiang Mai presents itself as an excellent location for harnessing renewable energy through solar photovoltaic systems.
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 88 locations across Thailand. This analysis provides insights into each city/location's potential for harnessing solar energy through PV installations.
Link: Solar PV potential in Thailand by location
Solar output per kW of installed solar PV by season in Chiang Mai
Seasonal solar PV output for Latitude: 18.7929, Longitude: 99.0004 (Chiang Mai, Thailand), 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 18° South in Chiang Mai, Thailand
To maximize your solar PV system's energy output in Chiang Mai, Thailand (Lat/Long 18.7929, 99.0004) throughout the year, you should tilt your panels at an angle of 18° 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 Chiang Mai, Thailand
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 Chiang Mai, Thailand. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 18° South tilt angle throughout the year.
| Overall Best Summer Angle | Overall Best Autumn Angle | Overall Best Winter Angle | Overall Best Spring Angle |
|---|---|---|---|
| 3° South in Summer | 25° South in Autumn | 34° South in Winter | 12° 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 Chiang Mai, Thailand
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 Chiang Mai, Thailand.
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 Chiang Mai, Thailand
The topography around Chiang Mai, Thailand is generally flat. The terrain is mostly composed of low hills and mountains with some plains, however it contains no large bodies of water or significant elevation changes. Areas most suited to large-scale solar PV in the vicinity of Chiang Mai would be on the plains and low hills as these areas offer the best exposure to direct sunlight.
Thailand solar PV Stats as a country
Thailand ranks 26th in the world for cumulative solar PV capacity, with 3,049 total MW's of solar PV installed. This means that 2.90% of Thailand's total energy as a country comes from solar PV (that's 29th in the world). Each year Thailand is generating 44 Watts from solar PV per capita (Thailand ranks 54th in the world for solar PV Watts generated per capita). [source]
Are there incentives for businesses to install solar in Thailand?
Yes, there are several incentives for businesses wanting to install solar energy in Thailand. The Thai government offers a number of tax incentives and subsidies for businesses that install solar energy systems. These include a 30% corporate income tax deduction on the cost of installing solar panels, as well as an exemption from import duties on certain components used in the installation process. Additionally, businesses can benefit from net metering policies which allow them to sell excess electricity generated by their solar system back to the grid at a premium rate. Finally, businesses may also be eligible for grants and other financial assistance from various government agencies and private organizations.
Do you have more up to date information than this on incentives towards solar PV projects in Thailand? Please reach out to us and help us keep this information current. Thanks!
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Author: Aaron Robinson
Publisher: profileSOLAR.com
First Published: Sunday 10th of December 2023
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.
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.




