Multijunction solar cells are being developed to make solar power more efficient and cost-effective for both space and Earth applications. By splitting sunlight into different energy intervals, these cells can convert more energy from the sun, leading to higher efficiency rates. In fact, cascade solar cells on Earth now exceed 45% efficiency, much higher than traditional solar arrays. This technology also allows for concentrated solar power, reducing the size and cost of solar panels. Overall, multijunction solar cells show great promise for improving solar energy systems and making them more accessible for widespread use.