Haining, Zhejiang, China, located in the Northern Sub Tropics at coordinates 30.5384°N, 120.6889°E, offers reasonably good conditions for year-round solar energy generation, though with notable seasonal variations that affect overall efficiency.

Seasonal Solar Performance

The solar energy output at Haining varies significantly throughout the year. Summer provides the strongest performance at 4.92 kWh per day per kW of installed solar capacity, making it the ideal season for solar generation. Spring follows as the second-best period with 4.27 kWh per day per kW, offering excellent solar conditions as daylight hours increase and weather improves. Autumn sees a decline to 3.82 kWh per day per kW as conditions become less favorable. Winter presents the most challenging period for solar generation, dropping to just 3.03 kWh per day per kW of installed capacity, representing a significant reduction compared to peak summer performance. For optimal year-round energy production from a fixed panel installation at this location, solar panels should be tilted at 28 degrees facing south. This angle maximizes total annual solar output by accounting for the sun's varying position throughout the seasons and the location's specific latitude.

Local Factors Affecting Solar Production

Several environmental and weather factors in Haining can significantly impact solar energy production and require careful consideration during installation. Air pollution represents a major challenge in this region of China. Industrial emissions and urban smog can create a persistent haze that reduces the amount of sunlight reaching solar panels, particularly during winter months when atmospheric conditions tend to trap pollutants closer to the ground. The area experiences a subtropical monsoon climate with high humidity levels, especially during summer months. This humidity can lead to moisture accumulation on panel surfaces and create conditions for dust and dirt to adhere more readily to the glass, reducing light transmission and energy output. Seasonal weather patterns include heavy rainfall during monsoon periods and occasional typhoons, which can create temporary but significant reductions in solar generation. The region also experiences periods of dense fog, particularly in autumn and winter, which can substantially reduce solar irradiance.

Preventative Measures for Enhanced Performance

Several installation strategies can help mitigate these environmental challenges and optimize solar energy production in Haining. Regular cleaning schedules become essential due to the combination of air pollution and humidity. Installing automated cleaning systems or establishing frequent manual cleaning routines can maintain panel efficiency by removing accumulated dust, smog residue, and other contaminants that reduce light transmission. Proper panel spacing and mounting systems should account for the high humidity environment. Adequate ventilation behind panels helps prevent moisture buildup and maintains optimal operating temperatures, while corrosion-resistant mounting hardware ensures long-term structural integrity in the humid subtropical climate. Selecting solar panels with anti-reflective coatings and hydrophobic surfaces can help reduce the impact of dust accumulation and make cleaning more effective. These specialized coatings allow panels to maintain higher efficiency levels between cleaning cycles. Installing monitoring systems becomes particularly valuable in this environment, as they can quickly identify performance drops due to soiling or weather-related issues, enabling prompt maintenance responses to restore optimal energy production.

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 Haining

Seasonal solar PV output for Latitude: 30.5384, Longitude: 120.6889 (Haining, 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 Haining, China

To maximize your solar PV system's energy output in Haining, China (Lat/Long 30.5384, 120.6889) 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 Haining, 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 Haining, 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 Haining, 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 Haining, China.

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 Haining, China

Topographical Features of Haining Region

Haining is situated in the northern part of Zhejiang Province in eastern China, positioned within the fertile Yangtze River Delta region. The city lies in a predominantly flat to gently rolling landscape that characterizes much of the Jiangnan area. The terrain consists primarily of alluvial plains formed by centuries of sediment deposition from the Yangtze River system, creating relatively low-lying areas with minimal elevation changes across most of the region.

The topography around Haining features a gradual transition from the flat deltaic plains in the north toward slightly more undulating terrain as one moves southward. The elevation typically ranges from near sea level in the northern areas to modest hills reaching several hundred meters in the southern portions of the broader region. The landscape is interspersed with numerous waterways, including rivers, canals, and traditional irrigation channels that have shaped the agricultural character of the area for generations.

To the north and northeast of Haining, the terrain remains consistently flat, extending toward Hangzhou Bay and the East China Sea. This northern area represents some of the most level ground in the region, with expansive agricultural fields and relatively few natural obstacles. The western areas maintain similar characteristics, with gentle slopes and broad valleys that provide excellent drainage and accessibility.

Optimal Areas for Large-Scale Solar Development

The flat to gently rolling plains extending north and northwest of Haining present the most favorable conditions for large-scale solar photovoltaic installations. These areas offer extensive tracts of relatively level land that would minimize grading requirements and construction costs while maximizing the efficiency of solar panel orientation and maintenance access.

The agricultural plains to the west and southwest of the city center also provide excellent potential for solar development, particularly in areas where traditional farming may be transitioning or where dual-use agricultural-solar projects could be implemented. The consistent topography in these regions would allow for standardized installation techniques and optimal spacing between solar arrays.

Areas closer to the transportation infrastructure, including the regions near major roads and rail connections, would offer additional advantages for solar development due to easier access for construction equipment and ongoing maintenance operations. The relatively stable soil conditions typical of the alluvial plains would provide solid foundations for mounting systems without requiring extensive geological preparation.

The eastern areas toward Hangzhou Bay, while topographically suitable, may face some limitations due to proximity to urban development and existing industrial zones. However, the consistently flat terrain throughout this coastal approach maintains the fundamental geographical advantages for solar installation, should suitable parcels become available for development.

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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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

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.