On 8 September 2011 Nuon announced the pilot plant would be closed down since no investor for production expansion could be found. However, on 7 May 2012 Nuon announced that Helianthos has been sold to HyET Solar. Process technology The process uses a temporary substrate on which flexible thin-film solar cells are deposited. The use of the temporary substrate allows relatively high processing temperatures while using (semi-)continuous roll-to-roll (or reel-to-reel) production processes and cost-efficient, abundantly available materials. The active layers of such solar cells comprise a transparent conductive oxide layer (TCO), an active absorbent layer (e.g. thin-film silicon), and a back contact layer (e.g. a reflective metal layer). Process sequence The key steps in the process sequence are: Deposit the TCO layer on a temporary metal substrate foil using chemical vapor deposition (CVD) at about 500 °C (932 °F) . Deposit the active absorber layer (e.g. thin film silicon layer) using plasma enhanced CVD Deposit the reflective back contact by means of physical vapor deposition Pattern for monolithic interconnection Laminate to a permanent carrier foil Remove the temporary substrate foil by means of wet etching Confectioning, contact application and encapsulation Applications Using this process, flexible photovoltaic (PV) laminates are fabricated that can substantially reduce the per-kilowatt hour costs of solar electricity. Further, the resulting photovoltaic laminates are lightweight, rugged and offer certain freedoms of design. PV laminates have the potential to be used for a range of applications, including: Large area roofing and other large area applications to generate electricity Rural electrification Industrial applications Portable applications. Sources Nuon Helianthos See also Solar cell Thin-film cells Nuon References Challenges in the development of thin-film silicon PV by Bernd Stannowski presentation Advanced Thin-Film Silicon Solar Cells World Record for thin film solar cells of Nuon Helianthos IKEA gets current from the roof Nuon Press Statement about the closing down of the pilot plant Energy conversion Thin-film cells