Concentrating solar power (CSP) plants utilize reflective facets in heliostats to concentrate sunlight, but these facets contribute significantly to the cost of the plant. This study explores a novel heliostat facet design utilising long aluminium reflector panels to reduce costs. Three different support structure concepts for a 6 m long aluminium reflector facet are proposed and analysed: a frame support, a sandwich panel, and a formed sheet metal design. The facet concepts are compared based on their material costs and optical performance, quantified by the root mean square (RMS) slope error. Analytical calculations and finite element analysis are employed to determine the slope errors under representative loading conditions, including gravity and wind loads, at different facet angles. The results show that the frame-supported panel and formed sheet facets are the cheapest, and the formed sheet has the best optical performance. The sandwich panel is the most expensive and has the worst optical performance. This work demonstrates the potential of long aluminium reflector designs to reduce heliostat costs while maintaining optical performance, which could improve the economic viability of CSP plants.