Roppongi, Japan, situated at latitude 35.6556 and longitude 139.7378, presents a moderately favorable location for solar PV energy generation throughout the year. This bustling district in Tokyo experiences distinct seasonal variations in solar output, reflecting its position in the Northern Temperate Zone.

Seasonal Solar Performance

Solar energy production in Roppongi peaks during the summer months, with an average daily output of 5.27 kWh per kW of installed capacity. Spring closely follows with 5.22 kWh/day, making these seasons the most productive for solar generation. Autumn and winter see a notable decrease in output, with 3.56 kWh/day and 3.44 kWh/day respectively, due to shorter daylight hours and lower sun angles.

Optimal Panel Positioning

To maximize year-round solar energy production in Roppongi, fixed solar panels should be installed at a tilt angle of 33 degrees facing south. This angle optimizes the panels' exposure to sunlight throughout the year, accounting for seasonal variations in the sun's path across the sky.

Environmental Considerations

While Roppongi's climate is generally conducive to solar energy production, there are some environmental factors to consider. The region experiences a rainy season from June to July, which can temporarily reduce solar output. Additionally, occasional typhoons in late summer and early autumn may pose risks to solar installations.

To mitigate these challenges, solar installations in Roppongi should incorporate robust mounting systems capable of withstanding high winds. Regular cleaning and maintenance of panels is also crucial to combat the effects of urban pollution and dust accumulation, which can impact efficiency.

Urban Context

As a densely populated urban area, Roppongi faces potential shading issues from surrounding high-rise buildings. Careful site assessment and potentially employing micro-inverters or power optimizers can help maximize energy production in partially shaded conditions.

Despite these challenges, Roppongi's location offers a good balance of solar potential throughout the year, making it a viable option for clean energy generation in the heart of Tokyo.

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 Roppongi

Seasonal solar PV output for Latitude: 35.6556, Longitude: 139.7378 (Roppongi, 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 Roppongi, Japan

To maximize your solar PV system's energy output in Roppongi, Japan (Lat/Long 35.6556, 139.7378) 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 Roppongi, 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 Roppongi, 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	41° South in Autumn	50° 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 Roppongi, 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 Roppongi, Japan.

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 Roppongi, Japan

Roppongi, located in Tokyo, Japan, sits within the bustling urban landscape of one of the world's largest cities. The topography of the area around Roppongi is characterized by a mix of flat and gently rolling terrain, typical of Tokyo's central districts. The neighborhood itself is situated on a slight elevation, with some areas rising to about 30-40 meters above sea level. The surrounding area is densely populated and heavily developed, with numerous high-rise buildings, office complexes, and residential structures dominating the skyline. This urban environment means that natural topographical features are largely obscured or altered by human development. However, the general landscape of the region was originally part of the Musashino Plateau, a relatively flat expanse that covers much of the Tokyo metropolitan area. To the west of Roppongi, the land gradually rises towards the Akasaka and Aoyama districts, while to the east, it slopes gently down towards Tokyo Bay. The nearby Aoyama Cemetery provides one of the few large open spaces in the vicinity, offering a glimpse of the area's original topography with its subtle undulations.

Potential for Large-scale Solar PV

When considering areas nearby that would be most suited to large-scale solar photovoltaic (PV) installations, it's important to note that the dense urban environment of central Tokyo presents significant challenges. However, some potential options in the broader region include: The Tokyo Bay area, particularly reclaimed land and industrial zones along the waterfront, could offer large, flat spaces suitable for solar installations. These areas are relatively close to Roppongi and have fewer obstructions to sunlight. The outskirts of Tokyo, such as parts of Chiba Prefecture to the east or Kanagawa Prefecture to the south, may provide more open land for large-scale solar projects. These areas often have a mix of industrial and agricultural land that could be repurposed for solar energy production. Rooftops of large commercial and industrial buildings throughout Tokyo could collectively offer significant space for solar PV installations. While not a single large-scale project, a distributed network of rooftop solar panels could contribute substantially to renewable energy generation in the region. It's worth noting that any large-scale solar PV project in or near Tokyo would need to carefully consider factors such as land availability, local regulations, grid connectivity, and the impact on the urban landscape. The most practical approach may involve a combination of smaller installations spread across various suitable locations in the greater Tokyo area.

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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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

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.