Nils Gustaf Dalén (November 30, 1869 - December 9, 1937) was a Swedish inventor and industrialist, the founder of AGA, who was awarded the Nobel Prize in Physics in 1912 for his work on automatic gas regulator controlled buoys.
Dalén was born in Stenstorp and earned his Master's degree and a Doctorate at the Chalmers University of Technology. Daléns most important and most well known invention is the sun valve which made the AGA lighthouse possible. Dalén was blinded in a gas explosion accident earlier the same year as he was awarded the prize (1912). This has led to speculation that he was selected partly out of sympathy.
Despite his blindness, Dalén remained in control of AGA until 1937.
The award of the Nobel Prize to Dalén has sometimes been viewed with controversy, but was actually closer to the general terms of Nobel's will than most awards in physics. Dalén made developments in acetylene chemistry to get a very bright light, developed safe storage methods, and then engineered a special valve that was controlled by the sun, so that the resulting buoys would only operate at night, prolonging their life to about a year. To a rugged coastal area like Scandinavia, these mass-produced long-lived minimal maintenance buoys were a significant boon to safety and livelihood.