Solar PV Analysis of Tongxiang, China
Tongxiang, Zhejiang, China, located at coordinates 30.6295, 120.5619 in the Northern Sub Tropics, offers a reasonably good location for solar PV energy generation throughout the year, with seasonal variations in production.
Seasonal Solar Production
Solar panels in Tongxiang generate varying amounts of electricity depending on the season. Summer is the most productive time, yielding about 4.91 kWh per day for each kilowatt of installed capacity. Spring follows as the second most productive season with 4.27 kWh/day. Autumn sees a moderate decrease to 3.82 kWh/day, while winter has the lowest output at 3.06 kWh/day per kilowatt installed.
This seasonal pattern means that Tongxiang experiences roughly 60% more solar production in summer compared to winter months. Despite the winter reduction, the region maintains relatively consistent solar generation year-round compared to locations at higher latitudes, which typically see more dramatic seasonal differences.
Optimal Panel Installation
For fixed solar panel installations in Tongxiang, Zhejiang, the ideal tilt angle to maximize year-round energy production is 28 degrees facing South. This specific angle optimizes the capture of solar energy across all seasons, balancing between the higher summer sun and lower winter sun positions.
Environmental Considerations
Several environmental factors could affect solar production in Tongxiang:
- High humidity levels in this subtropical region can reduce panel efficiency and may contribute to faster degradation of components if not properly protected.
- Seasonal monsoon rains, particularly during the summer, can temporarily reduce solar output despite it being the sunniest season.
- Air pollution from nearby industrial areas may deposit particulate matter on panels, reducing efficiency over time.
- Typhoons occasionally affect this coastal region, potentially causing physical damage to installations.
Preventative Measures
To optimize solar production in Tongxiang, Zhejiang, consider implementing these protective measures:
- Install panels with high humidity resistance ratings and ensure proper sealing of all electrical components.
- Implement a regular cleaning schedule, especially during dry periods when dust and pollution accumulation is highest.
- Use mounting systems designed to withstand typhoon-force winds, with additional reinforcement for areas exposed to strong gusts.
- Consider slightly elevated tilt angles (30-32 degrees) if winter production is particularly important, as this can improve performance during low-sun months.
- Install systems with remote monitoring to quickly identify and address any performance issues caused by environmental factors.
With proper installation and maintenance, Tongxiang's relatively consistent solar radiation throughout the year makes it a viable location for solar PV energy generation, despite the seasonal variations and environmental challenges.
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 319 locations across China. This analysis provides insights into each city/location's potential for harnessing solar energy through PV installations.
Link: Solar PV potential in China by location
Solar output per kW of installed solar PV by season in Tongxiang
Seasonal solar PV output for Latitude: 30.6295, Longitude: 120.5619 (Tongxiang, China), 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 28° South in Tongxiang, China
To maximize your solar PV system's energy output in Tongxiang, China (Lat/Long 30.6295, 120.5619) throughout the year, you should tilt your panels at an angle of 28° 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 Tongxiang, China
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 Tongxiang, China. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 28° South tilt angle throughout the year.
| Overall Best Summer Angle | Overall Best Autumn Angle | Overall Best Winter Angle | Overall Best Spring Angle |
|---|---|---|---|
| 15° South in Summer | 36° South in Autumn | 46° South in Winter | 23° 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 Tongxiang, China
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 Tongxiang, China.
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 Tongxiang, China
Tongxiang is a county-level city situated in the northern part of Zhejiang Province in eastern China. The topography around Tongxiang is predominantly characterized by flat, lowland plains as it sits within the Yangtze River Delta region. This area features a gentle landscape with minimal elevation changes, typically ranging from just 2 to 10 meters above sea level across most of the territory. The terrain consists mainly of alluvial plains formed by sediment deposits from the Yangtze River system over thousands of years. The flat nature of the landscape has historically made it ideal for agriculture, particularly rice cultivation, which remains an important economic activity in the region. Interspersed throughout these plains are numerous water bodies including rivers, canals, and lakes that form an extensive water network throughout the area.
Water Features
The Grand Canal, one of China's most significant historical waterways, passes through the western portion of Tongxiang, influencing the local topography with its associated waterways and embankments. The region also contains numerous smaller rivers and streams that flow generally eastward toward Hangzhou Bay, which lies approximately 30-40 kilometers to the southeast of Tongxiang.Urban and Rural Landscape
The built environment in Tongxiang includes the main urban center and several smaller towns and villages scattered across the plains. Traditional water towns like Wuzhen, famous for its ancient architecture and canal networks, represent the historical settlement patterns adapted to this low-lying, water-rich environment.Surrounding Elevations
While Tongxiang itself is predominantly flat, the broader regional topography becomes more varied as one moves away from the central delta area. To the southwest, the terrain gradually rises toward the foothills of the Tianmu Mountains in western Zhejiang Province. These more elevated areas begin approximately 40-50 kilometers from Tongxiang central area. To the northeast, the landscape continues as flat plains extending toward Shanghai.Potential Areas for Solar PV Development
The flat topography of Tongxiang and surrounding areas presents several advantages for large-scale solar PV installation. The most suitable areas would be: The agricultural plains to the north and northeast of Tongxiang city proper offer extensive flat terrain with minimal shading concerns. These areas receive consistent solar exposure due to the absence of significant natural barriers or elevation changes. Slightly elevated areas along the western periphery of Tongxiang county would provide good drainage characteristics, reducing potential flood risks that might affect solar installations in the lowest-lying areas of the delta. Former industrial lands or brownfield sites around the urban periphery represent opportunities for solar development without displacing productive agricultural land. These areas often have existing infrastructure connections that can be beneficial for energy transmission. Less productive agricultural lands with sandy or less fertile soil compositions would minimize the impact on food production while utilizing land for renewable energy generation. The challenge in this region relates not to the topography itself, which is highly favorable for solar installation, but rather to land availability given the dense population and intensive agricultural use. Areas that balance minimal agricultural productivity with good accessibility and proximity to existing electrical infrastructure would represent the optimal locations for large-scale solar PV development. Areas to avoid would include the wetland zones closer to Hangzhou Bay and lands subject to seasonal flooding along major waterways, as these present environmental and operational challenges for solar installations despite their flat topography.China solar PV Stats as a country
China ranks 1st in the world for cumulative solar PV capacity, with 306,973 total MW's of solar PV installed. This means that 6.20% of China's total energy as a country comes from solar PV (that's 13th in the world). Each year China is generating 217 Watts from solar PV per capita (China ranks 24th in the world for solar PV Watts generated per capita). [source]
Are there incentives for businesses to install solar in China?
Yes, there are several incentives for businesses wanting to install solar energy in China. These include subsidies from the Chinese government, preferential tax policies, and access to low-interest loans. Additionally, businesses may be eligible for renewable energy certificates (RECs) which can be sold on the open market for additional income.
Do you have more up to date information than this on incentives towards solar PV projects in China? 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: Monday 16th of June 2025
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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Calculate Your Optimal Solar Panel Tilt Angle: A Comprehensive Guide
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