Wind turbines stand in the Baltic 1 offshore wind farm on April 29, 2011 in the Baltic Sea near Zingst, Germany. Baltic 1, a project of German energy utility EnBW that includes 21 turbines rated at 2.3 megawatts each, will be Germany's first commercial offshore wind farm once it officially begins operation on May 2. Germany has thus far lagged in offshore wind farm construction when compared to neighbors like Great Britain and Denmark, though German Chancellor Angela Merkel has vowed to invest heavily into offshore wind farms as part of an overall policy to encourage renewable energy production. (Photo by Joern Pollex/Getty Images)

A general view shows the Krasnoyarsk hydro-electric power station on the Yenisei River near the Siberian city of Krasnoyarsk, Russia, January 13, 2016. The power plant, owned by EuroSibEnergo company, part of En+ Group, with a generating capacity of 6,000 megawatt (MW), has a ferro-concrete dam 124-metres high and 1065-metres long and is the second largest Russian hydroelectric power station. About 85% of the energy generated is intended for the Rusal Krasnoyarsk aluminium smelter, according to representatives of the power station. (Photo by Ilya Naymushin/Reuters)

Rope access technicians carry out maintenance service on wind turbines including repairs, blade inspections and cleaning in Izmir, Turkey on February 19, 2021. In Turkey, where investments in renewable energy has increased, there are wind tribunes over 3,500. (Photo by Mahmut Serdar Alakus/Anadolu Agency via Getty Images)

Indonesian women sit on a hill as the Suralaya coal power plant looms in the background in Cilegon, Indonesia, on January 8, 2023. A plan for how Indonesia will spend $20 billion to transition to cleaner energy was submitted Wednesday, Aug. 16, to the government and its financing partners, the planners said. (Photo by Dita Alangkara/AP Photo)

In this photo provided by Jean Revillard, Solar Impulse 2, a plane powered by the sun's rays and piloted by Andre Borschberg, approaches Kalaeloa Airport near Honolulu, Friday, July 3, 2015. His 120-hour voyage from Nagoya, Japan broke the record for the world's longest nonstop solo flight, his team said. (Photo by Jean Revillard/Global Newsroom via AP Photo)

“NASA's Pathfinder, Pathfinder Plus, Centurion and Helios Prototype were an evolutionary series of solar- and fuel-cell-system-powered unmanned aerial vehicles. AeroVironment, Inc. developed the vehicles under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. They were built to develop the technologies that would allow long-term, high-altitude aircraft to serve as “atmospheric satellites”, to perform atmospheric research tasks as well as serve as communications platforms”. – Wikipedia

Photo: The solar-electric Helios Prototype flying wing is flies over the Hawaiian islands of Niihau and Lehua during the first solar-powered test flight July 14, 2001 from the U.S. Navy's Pacific Missile Range Facility on Kauai, HI. The 18-hour flight was a functional checkout of the aircraft's systems and performance in preparation for an attempt to reach sustained flight at 100,000 feet altitude later in the summer. (Photo Courtesy of NASA/Getty Images)

Women carry gas cylinders to fill them at a distribution point in Cairo January 19, 2015. Egypt is going through its worst energy crisis in decades and is seeking fresh sources of natural gas, which powers most of its homes and factories. (Photo by Mohamed Abd El Ghany/Reuters)