photoaging

The aging phenomena that appear due to the accumulation of skin damage from ultraviolet rays in sunlight are called photoaging. Unlike natural aging, photoaging progresses mainly due to external factors such as UV rays. Because it causes spots, wrinkles, and sagging of the skin, UV protection is important.

Spring (March–May)

Solar power has the characteristic that panel conversion efficiency decreases when temperatures are too high, so spring (March to May), when temperatures are moderate and solar irradiation increases, enables the most efficient power generation. In summer, although solar irradiation is high, efficiency declines due to the high temperatures.

Yamanashi Prefecture

Yamanashi Prefecture is known as one of the sunniest prefectures in Japan. According to data from the Japan Meteorological Agency, Kofu City in Yamanashi often records the longest annual sunshine duration in the country, making it well-suited for installing solar power facilities. Okinawa Prefecture, while a southern region with strong sunlight, can have fewer sunshine hours than Yamanashi due to frequent typhoons and rain.

3rd place

Japan boasts the world’s third-largest installed capacity of solar power. China ranks first, and the United States second. In Japan, the shift toward renewable energy has advanced since the Great East Japan Earthquake, with a particularly rapid increase in the adoption of solar power.

space satellite

The first practical use of solar cells was on the American artificial satellite Vanguard 1, launched in 1958. It reportedly used solar cells as its main power source and operated in space for 20 days. Because solar cells were first used not on Earth but in outer space, research and practical applications subsequently advanced widely.

sunshine duration

Sunshine duration refers to the length of time during which the sun’s rays directly illuminate the Earth’s surface, measured at meteorological stations and observatories using a sunshine recorder. It is considered important data in fields such as agriculture, daily life, and energy. You can check sunshine duration data for locations across Japan on the Japan Meteorological Agency’s website.

happiness hormone

Serotonin stabilizes mood and mental state in the brain and brings about feelings of happiness, which is why it is also called the “happy hormone.” Exposure to sunlight increases the secretion of serotonin, making it easier to feel cheerful.