Solar PV Analysis of Arakawa, Japan
Arakawa, Tokyo, Japan, located in the Northern Temperate Zone, presents a generally favorable environment for solar energy generation throughout the year. This location experiences distinct seasonal variations in solar output, which can impact the overall efficiency of photovoltaic (PV) systems.
Seasonal Solar Performance
Summer and spring prove to be the most productive seasons for solar energy in Arakawa. During summer, solar panels can generate an impressive 5.28 kWh per day for each kilowatt of installed capacity. Spring follows closely behind with 5.26 kWh/day. These seasons offer longer daylight hours and more direct sunlight, maximizing solar energy production.
Autumn and winter see a noticeable decrease in solar output. Autumn produces 3.62 kWh/day, while winter drops slightly to 3.50 kWh/day per kW of installed solar. Although these figures are lower, they still indicate a significant potential for year-round solar energy generation.
Optimal Panel Installation
To maximize year-round solar production in Arakawa, Tokyo, fixed solar panels should be tilted at a 33-degree angle facing south. This optimal angle ensures the panels capture the most sunlight throughout the year, accounting for the Earth's elliptical orbit and the location's specific latitude.
Environmental Considerations
While Arakawa's climate is generally conducive to solar energy production, there are some factors to consider:
- Rainy season: June to July can see increased cloud cover and rainfall, potentially reducing solar output.
- Snow: Winter months may bring occasional snowfall, which can temporarily cover panels and decrease efficiency.
To mitigate these issues, consider installing panels at a steeper angle to encourage snow sliding off and using water-resistant, high-quality panels. Regular maintenance and cleaning, especially after snowfall or during the rainy season, can help maintain optimal performance.
Overall, Arakawa's location offers a promising environment for solar PV systems, with strong potential for energy generation throughout the year, especially during the spring and summer months.
Note: The Northern Temperate Zone extends from 35° latitude North up to 66.5° latitude.
So far, we have conducted calculations to evaluate the solar photovoltaic (PV) potential in 187 locations across Japan. This analysis provides insights into each city/location's potential for harnessing solar energy through PV installations.
Link: Solar PV potential in Japan by location
Solar output per kW of installed solar PV by season in Arakawa
Seasonal solar PV output for Latitude: 35.754, Longitude: 139.7803 (Arakawa, Japan), 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 33° South in Arakawa, Japan
To maximize your solar PV system's energy output in Arakawa, Japan (Lat/Long 35.754, 139.7803) throughout the year, you should tilt your panels at an angle of 33° 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 Arakawa, Japan
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 Arakawa, Japan. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 33° South tilt angle throughout the year.
| Overall Best Summer Angle | Overall Best Autumn Angle | Overall Best Winter Angle | Overall Best Spring Angle |
|---|---|---|---|
| 20° South in Summer | 42° South in Autumn | 51° South in Winter | 29° 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 Arakawa, Japan
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 Arakawa, Japan.
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 Arakawa, Japan
The area around Arakawa, Japan, which is located in the northern part of Tokyo, is characterized by a largely urban and suburban landscape. The topography is generally flat, as it's situated in the Kanto Plain, one of Japan's largest flat areas. This region was historically a low-lying floodplain formed by the Arakawa River and other waterways, but it has been extensively developed over time.
The immediate vicinity of Arakawa is densely populated, with a mix of residential, commercial, and light industrial areas. You'll find a network of streets, buildings, and infrastructure typical of a Tokyo suburb. While there are some small parks and green spaces scattered throughout, large open areas are limited within the urban core.
As you move further from the center of Arakawa, especially to the north and east, the landscape becomes slightly more varied. You might encounter some gentle slopes and small hills, but dramatic elevation changes are rare in this part of Tokyo. The Arakawa River, which gives the area its name, flows nearby, providing some natural relief to the urban environment.
Regarding areas suitable for large-scale solar PV (photovoltaic) installations, the urban nature of Arakawa and its surroundings poses some challenges. However, there are potential options to consider:
1. Rooftops of large buildings: The numerous warehouses, factories, and commercial buildings in and around Arakawa offer extensive flat surfaces that could be utilized for solar panels. While not a single large-scale installation, a network of rooftop solar systems could provide significant power generation.
2. Redeveloped industrial zones: Some older industrial areas in the broader Tokyo region are being redeveloped. These could potentially accommodate ground-mounted solar arrays if land use permits.
3. Suburban and rural areas further out: Moving away from the immediate Arakawa area, towards the outskirts of Tokyo and into neighboring prefectures like Saitama or Chiba, you'll find more open spaces that could be suitable for large-scale solar farms. These areas often have a mix of agricultural land and less densely populated regions that might be repurposed for solar energy production.
4. Floating solar: Given the presence of the Arakawa River and other water bodies in the broader region, floating solar panel installations on reservoirs or water treatment facilities could be an innovative solution for large-scale solar PV in this urban environment.
It's important to note that any large-scale solar PV project in this area would need to carefully consider land availability, local regulations, and the impact on the community and environment. The dense urban nature of the Tokyo metropolitan area means that truly large-scale installations are more likely to be feasible in more rural regions further from the city center.
Japan solar PV Stats as a country
Japan ranks 3rd in the world for cumulative solar PV capacity, with 74,191 total MW's of solar PV installed. This means that 8.30% of Japan's total energy as a country comes from solar PV (that's 9th in the world). Each year Japan is generating 590 Watts from solar PV per capita (Japan ranks 4th in the world for solar PV Watts generated per capita). [source]
Are there incentives for businesses to install solar in Japan?
Yes, there are several incentives for businesses wanting to install solar energy in Japan. These include the Feed-in Tariff (FIT) program, which provides a fixed price for electricity generated from renewable sources such as solar; subsidies and grants from local governments; tax credits; and loans with low interest rates. Additionally, businesses may be eligible for additional incentives depending on their location and type of installation.
Do you have more up to date information than this on incentives towards solar PV projects in Japan? 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: Sunday 29th of September 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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