In Ulsan, South Korea, the Yuldong With You apartments have emerged as a pioneering example of sustainable urban living with the world's first hydrogen-powered complex. Featuring 437 units powered entirely by hydrogen fuel cells, residents can enjoy reduced electric bills by 30-40% while positively impacting the environment. This innovative approach is a significant step towards cleaner energy in cities like Ulsan, which heavily rely on traditional dirty fuel sources. The Yuldong Combined Heat and Power Plant, located nearby, supplies clean electricity and heat to the apartments by utilizing hydrogen as a byproduct from neighboring industries. This method has proven to be cost-effective, generating 840 megawatts of energy since its launch, emphasizing the potential of hydrogen as a game-changer in urban energy systems. With three fuel cells on the complex's roof producing 1.32 MW of electricity from hydrogen, the apartments also benefit from a planet-friendly heating system. Heat produced is captured and stored in a thermal tank, providing hot water for heating units. The city officials in Ulsan are actively working towards making hydrogen-generated electricity more accessible and affordable, aiming to amend regulations to promote cleaner energy initiatives. The Yuldong With You apartments set a new standard for eco-friendly urban living, showcasing how technologies like hydrogen can revolutionize city infrastructure. As cities worldwide embrace clean energy solutions, residents can expect savings on electric bills and a more sustainable way of living. With the potential to become fully carbon neutral, these apartments pave the way for a greener future in urban development, inspiring other cities to adopt similar environmentally friendly practices.