Japan Domestic consumer PV roof system

Dec 08, 2025

FUTURE

According to the Japanese government's plan, photovoltaic power generation will account for 14% to 16% of its total electricity demand by 2030, which means Japan must double its photovoltaic power generation capacity in less than 10 years. However, Japan, as one of the countries that developed photovoltaics earlier, has already developed and used land suitable for photovoltaic power generation, and now there is very little land left that can be developed. It is predicted that in the next 10 years, rooftop solar power (TRS) may replace photovoltaic power plants and become Japan's main growth driver.

Understanding Japanese roof types and developing PV fixtures suitable for various roof types has become an urgent need for the Japanese market.

Japanese roofs are diverse and there are many types of roofing materials used. Due to limited space, this time I will first introduce to you the folding panel roof and the suitable solar photovoltaic fixtures among the metal roofs with the highest proportion.

Folding Panel Roof

Folded panels were developed with a focus on cross-sectional construction, typical of metal roofs, and their design blends well with large, long roofs, strength and economy.The folded plates can be directly covered on the beams and the main building, without the need for roof substrates, which shortens the construction period. It can show toughness even in strong wind areas and has strong rain resistance.

Use steel plates with a thickness of 0.6~1.2mm to form a larger height. This is a construction method in which tight frames are installed on the beam at intervals of about 3mm to 7mm and fixed directly to the beam.According to the different joining methods, there are mainly (1) seam type, (2) overlap type, (3) plug-in type.

（1） Seam Type

Clamp the fastening fittings attached to the tight frame (fixed to the beams by welding) between the ends of the two pieces of metal roofing material and wrap and tighten them with an electric seam sealer (clamping machine) to make them waterproof Sex is excellent. This is an economical method that reduces costs because the roof is completed by simply overlapping the roof clamping seams and bolts are no longer required.

There are protruding parts on this kind of roof, and suitable clamps that have been molded can be selected according to the shape and size of the protrusions.Our company currently provides the following fixtures:

solar panel mounting solution for tile roofs

（2）Overlap Type

This is a method where two pieces of metal roofing material are attached overlappingly to tension bolts on top of a tight frame and then tightened with nuts. It has particularly excellent cross-sectional strength and exhibits toughness even in areas with strong winds.Laptop roofs currently mainly use self-tapping screws to fix the photovoltaic panels.The Metal fittings is as shown below:

（3） Plug-in Type

This construction method involves joining two metal roofing materials to a tight frame with hangers (fasteners) and installing caps over the joints so that no bolts protrude from the roof surface and the roof looks clean.

However, this type of roof is currently generally made with L-foot holes.

When drilling holes in the roof, although measures such as waterproof rubber pads and sealants will be added to prevent leakage, there are still risks. Therefore, Japanese customers are eager to develop more non-punching solutions for roofs.

That's all for this introduction,we will continue to introduce other types of roofs and suitable roof photovoltaic fixtures in the future, so please continue to pay attention to the Xiamen Powerstone.