The peninsula features a large industrial park that was founded in 1928 and contains major facilities of Norsk Hydro, Yara, and REC (ScanWafer subsidiary). The area is served by the Bratsberg Line. 2,700 people work on the 1.5 km² peninsula that has about 30 companies, most of which are subsidiaries of Norsk Hydro, including Hydro's research park with 350 employees. A populated area south of the peninsula itself, which was initially housing for the Hydro employees, is also considered part of Herøya as a suburb of the city of Porsgrunn.