Solar PV Analysis of Okinawa, Japan
Situated at a latitude of 26.3317 and longitude of 127.813, Okinawa, Japan provides an excellent environment for solar photovoltaic (PV) power generation. The average energy yield per kilowatt (kW) of installed solar capacity varies by season but remains relatively high throughout the year. During the summer months, one can expect an average output of 5.86 kilowatt-hours (kWh) per day per kW, followed by spring with an output rate of 5.03 kWh/day/kW, autumn at 4.76 kWh/day/kW and winter at the lowest rate of 3.35 kWh/day/kW.
The higher energy yields during summer are attributable to longer daylight hours in this Northern Subtropical region compared to other seasons like winter that offer less sunlight exposure due to shorter days.
While there are no significant weather or environmental conditions that could severely hinder solar PV power generation in Okinawa, it is always beneficial to keep a close eye on local weather patterns over time as they may influence energy production levels from any given installation setup.
For instance, persistent cloud cover can potentially reduce the amount of sunlight reaching the panels thereby lowering their efficiency while extreme temperatures might cause equipment damage if not properly managed or monitored.
Regarding installation specifics for this location, it is recommended that fixed panel installations be tilted at an angle facing southward by approximately 23 degrees for optimal sun exposure throughout the year.
Preventative measures such as regular maintenance checks and using durable materials resistant to local climate conditions can help ensure greater energy production efficiency from these installations despite potential environmental challenges unique to this location.
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 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 Okinawa
Seasonal solar PV output for Latitude: 26.3317, Longitude: 127.813 (Okinawa, 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 23° South in Okinawa, Japan
To maximize your solar PV system's energy output in Okinawa, Japan (Lat/Long 26.3317, 127.813) throughout the year, you should tilt your panels at an angle of 23° 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 Okinawa, 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 Okinawa, Japan. As mentioned earlier, for fixed-panel solar PV installations, it is optimal to maintain a 23° South tilt angle throughout the year.
| Overall Best Summer Angle | Overall Best Autumn Angle | Overall Best Winter Angle | Overall Best Spring Angle |
|---|---|---|---|
| 11° South in Summer | 31° South in Autumn | 41° South in Winter | 20° 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 Okinawa, 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 Okinawa, 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 Okinawa, Japan
The topography of Okinawa, Japan is mostly flat with some hills and mountains to the north. The area is generally well-suited for large-scale solar PV installations, although there are some areas that may be more suitable than others due to their orientation or lack of obstructions. Areas near the coast tend to have fewer obstructions and a higher average number of sunny days, while areas further inland may experience more cloud cover. Additionally, any locations that face southward will receive the most direct sunlight throughout the day and would be ideal for large-scale solar PV systems.
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: Tuesday 4th of July 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.
