Introduction
Have you ever wondered, "I want to increase my solar power generation, but where should I install it?" In recent years, Japan has faced the problem of a shortage of land suitable for mega solar power plants. But don't worry! A technological innovation called next-generation solar cells holds new possibilities, allowing them to be installed on building walls and roofs. This article will explain in an easy-to-understand way why next-generation solar cells are attracting attention and how Japan's energy policy intends to utilize this technology.
Why "utilizing wall space" is the key to expanding solar power generation
Traditional mega solar power plants required vast tracts of land, but it has been discovered that next-generation solar cells can generate an astonishing amount of electricity even by utilizing just the walls of buildings.
- The amount of electricity generated by the wall surface is approximately 2.4 times that of the roof surface.
- 1537GW can be installed by utilizing buildings throughout Japan.
- Power generation equivalent to approximately 1.7 times the current annual electricity consumption.
A survey conducted by the Ministry of Land, Infrastructure, Transport and Tourism and Mitsubishi Research Institute showed that wall-mounted solar panels in urban areas were more widely used than roof-mounted ones. This is because the "thin and lightweight" characteristics unique to next-generation solar cells are being utilized.
Four types of next-generation solar cell technologies and their current status of practical application
There are currently four main types of next-generation solar cells attracting attention in the market. Let's explain the characteristics of each technology.
| kinds | Features | Practical application status |
|---|---|---|
| Belovskite solar cells | Japanese-developed technology: thin film and lightweight | It's on the verge of practical application due to its conversion efficiency and durability. |
| Thin crystalline silicon solar cells | Design that does not use glass or aluminum | Already in practical use |
| organic thin film solar cell | Flexible characteristics | One step ahead in practical application |
| Chalcopyrite solar cells | We are currently developing mass production technology. | Mass production is scheduled to begin in 2026 or later. |
In particular, "thin crystalline silicon solar cells" and "organic thin-film solar cells" are leading the way in terms of practical application. These are significantly lighter than glass modules and often do not require mounting frames.
Key features of velovskite solar cells:
- Conversion efficiency is improving.
- Durability is a challenge, but improvements are being made.
- We aim for a market share of 15% or more by 2040.
Supplementary information: Advantages and points to note regarding wall-mounted solar power generation
The reason next-generation solar cells can utilize wall surfaces is that they take a different approach than conventional glass panels.
- No mount required:Simply stick it on like a sticker.
- No drilling required:Can be installed without damaging the building structure.
- Cost reduction in construction:No major construction work is required, resulting in cost savings.
Advantages of wall-mounted power generation:
- Less seasonal fluctuation (stable power supply)
- The building's walls generate more electricity annually than its rooftops.
- High compatibility with thin and lightweight panels
However, there are some points to note:
- Currently, only about 20% of wall space is being utilized.
- The color of the building and the presence or absence of windows also affect the amount of electricity generated.
- The reduction in solar radiation due to building shadows must be taken into consideration.
The "PLATEAU" project, promoted by the Ministry of Land, Infrastructure, Transport and Tourism, utilizes 3D data from digital twins to accurately estimate the amount of solar power generation that can be installed. This technology is being tested in areas such as the Minato Mirai district of Yokohama City.
Energy Revolution: The "Wall" Illuminates Japan, Opening the Door to a Future
Until now, solar power generation has been associated with vast tracts of land. However, technological innovations such as next-generation solar cells have given rise to a new perspective: "the walls of buildings." This is not merely a technological advancement, but a turning point that will change Japan's energy strategy itself.
The Ministry of Economy, Trade and Industry has set a target for 2040 to significantly increase the share of solar power generation from the current approximately 80 GW to 331.1 GW. This was an impossible goal to achieve with mega solar power alone, but by promoting the use of next-generation solar cells on walls, a realistic path to this ambitious goal has emerged.
What's particularly interesting is that wall-mounted power generation generates more electricity annually than roof-mounted power generation. Even taking into account factors like building shadows and the presence or absence of windows, it's possible to produce a surprising amount of energy by effectively utilizing buildings in urban areas. This isn't just a matter for power companies; it's an important change that affects the living spaces of each and every one of us.
Energy issues are often perceived as being "far away" or involving "complex technology," but the innovation of next-generation solar cells will bring about a transformation in the buildings around us. Its simplicity—simply attaching it to a wall—actually embodies cutting-edge technology. This demonstrates its power to significantly change our "small everyday lives."
With growing environmental awareness, the very way we produce energy is changing. We need to break free from conventional thinking and actively embrace new technologies. Ideas that utilize previously overlooked spaces, such as wall-mounted solar power, offer hints that can be applied to solving problems in business and daily life.
Japan's Basic Energy Plan promotes the use of next-generation solar panels for wall and roof installation, as well as the utilization of abandoned farmland and agro-photovoltaic power generation. These approaches complement each other, aiming to build a sustainable energy society. How each of us perceives these changes is crucial.
Next-generation solar cells are not merely a technological innovation, but a crucial element that will change our future. Knowing that something as familiar as a wall can be a key factor in supporting Japan's energy independence, we can take more proactive action. Let's take that first step.
