As the world grapples with the challenges of climate change and seeks to reduce greenhouse gas emissions, solar power generation is an essential solution. Toshiba has been working hard on its Cu2O tandem solar cells and film-type perovskite solar cells as part of its renewable energy solutions. These innovations are not only efficient but also versatile, offering exciting prospects for large-scale power generation in diverse settings.
Cu2O Tandem Solar Cells: All About Efficiency
Cu2O (copper suboxide) tandem solar cells aim to improve overall power generation efficiency by stacking two solar cells on top of each other. The top cell is a transmission-type Cu2O cell, and the bottom cell is a Si (silicon) cell; both generate power. This stacked configuration allows these cells to be highly efficient, low-cost, and reliable.
A particularly promising application of these tandem solar cells is in electric mobility vehicles such as electric cars (EVs). The cells have the potential to supply large amounts of power in a compact form factor, making them ideal for vehicles with limited space. In the near future, EVs equipped with these cells could be powered for 30 to 50 km without recharging, covering the daily driving distance of a typical short-distance user when recharged by sunlight for a day.
Film-type Perovskite Solar Cells: Flexible and Lightweight
Film-type perovskite solar cells offer a solution for renewable energy generation in urban areas where conventional Si solar cells are challenging to install due to weight and rigidity constraints. These cells are lightweight, thin and can be installed on curved surfaces such as low-load-bearing roofs and walls.
This opens up the possibility for large-scale power generation in urban areas through a “local production for local consumption” model, utilizing the limited sunlight that falls on densely populated regions.
Overcoming Challenges: Power Conversion Efficiency
While polymer film-type perovskite solar cells offer numerous advantages, they have historically suffered from lower power conversion efficiency compared to silicon modules. Toshiba has tackled this problem head-on by developing a new one-step meniscus coating method. This approach has resulted in a power conversion efficiency of 15.1% for a polymer film-type perovskite solar cell, which Toshiba says is the world’s highest value for a cell of this type at 703 square-cm.
The coating process is also significantly faster than conventional methods, making mass production more efficient and bringing the technology closer to practical application.
Broad Applications and Future Prospects
Toshiba’s innovations in solar technology could have far-reaching implications. If perovskite solar cells were installed on the rooftops across Tokyo, they could cover a non-negligible amount of electricity the city consumes.
These cells also offer promising applications in agriculture. Their transparency can be controlled, making them suitable for use as greenhouse covers. This would allow for capturing the appropriate amount of sunlight needed for crops while generating electricity for agricultural operations.