When Ferdinand Grapperhaus heard that 40% of electricity is consumed by commercial buildings, he wanted to find a way that made commercial buildings energy neutral. His solution was transparent, glass windows, called the PowerWindow, that not only allowed people to have a good view, they also generate energy, more specifically 8-10 watts of power. To put this in perspective, this is enough power to charge a phone per every square meter two times a day. The windows are coated with the earth metal Thulium, and transforms oncoming visible light into near-infrared light, which is then transported toward the solar (photovoltaic) cells in the edges of the windows.
https://www.livescience.com/59683-windows-double-as-solar-panels.html
This amazing invention relates to engineering, especially environmental engineering, because the inventors of the PowerWindow applied their scientific knowledge of solar power, photovoltaic cells, and elements in the periodic table, to experiment and go through the engineering design process and create a way for the solar energy of the sun to be harnessed and transformed into electricity.
https://www.youtube.com/watch?v=mrMJ675kAQA