The　flat　plate　collector　(FPC)　has　a　low　economic　cost,　while　the　parabolic　trough　collector　(PTC)　has　a　high　heat　collection　temperature.　To　reduce　costs,　improve　efficiency,　and　promote　the　use　of　solar　energy,　this　study　proposes　a　new　two　-stage　solar　collector　that　couples　FPC　and　PTC.　The　main　objective　of　this　paper　is　to　verify　the　performance　of　this　two　-stage　solar　collector　when　containing　nanofluids.　This　collector　drives　the　organic　Rankine　cycle　(ORC)　with　four　nanoparticles　(Cu,　CuO,　TiO　2　,　and　Al　2　O　3　)　in　the　oil　heat　transfer　fluid.　The　FPC　outlet　temperature　in　the　two　-stage　solar　collector　is　optimized,　the　exergy　of　ORC　is　analyzed,　and　the　economics　of　the　new　system　using　nanofluid　are　calculated　and　compared　with　those　of　the　new　system　without　nanofluid.　Results　show　that　Cu　-oil　outperforms　the　other　nanofluids　in　terms　of　heat　transfer.　At　a　rated　output　power　of　5　kW,　the　new　two　-stage　solar　collector　with　5　%　Cu　-oil　can　reduce　economic　costs　by　6.8　%　compared　with　a　single　PTC.　Meanwhile,　the　ORC　with　a　two　-stage　solar　collector　using　5　%　Cu　-oil　reduces　the　economic　costs　by　5.7　%　compared　with　the　ORC　equipped　with　PTC　without　nanofluid.　The　new　system　has　a　minimum　payback　period　of　17.3　years,　and　increasing　the　output　power　of　the　ORC　is　beneficial　for　reducing　the　investment　payback　period　of　the　system.