The main source of income for Sirdal is the
Sira-Kvina Power Company which gets its power from the big
Sira and
Kvina rivers. The
waterfalls on the river
Sira are utilized in four power stations owned by Sira-Kvina power company. The company also owns three power stations in the
Kvina river system, hence the company's name. Total annual production is , total installation is . The largest power station,
Tonstad Hydroelectric Power Station, was inaugurated in 1968, with two units, each producing . The power station has now 4 units, each 160 MW, and one unit at , giving a total output of . Total annual production in this station is approximately , which makes Tonstad the largest power station in
Norway in terms of production. Sira-Kvina power company applied in 2007 for concession to expand the power station with two new units (reversible turbines), each containing , and the concession is pending.
Tourism is also an important source of income for the Sirdal economy, taking advantage of the extensive mountains, mountainous plateaus, lakes, and great views. There are multiple alpine resorts and hotels in the valley, as well as cottages and camping spots. Winter activities include six
ski resorts for winter enjoyment. Downhill ski areas include Tjørhomfjellet,
Bjørnestad Ski Centre,
Ålsheia Ski Centre, Fidjeland Ski Centre, and Ådneram Ski lift.
Cross-country skiers can enjoy dozens of trails over spectacular terrain. Summer activities include
hiking,
horseback riding, and river
rafting. ==History==