Clean technologies are imperative to sustainable development. However, due to industry uncertainty on the supply side and slow adoption on the demand side, so-called cleantech is still facing tremendous challenges. Specifically, the higher price of cleantech often deters adoption, and government subsidies will inevitably be cut when economic downturn hits again. In this paper, the researcher sheds light on the possibility of frugal innovation to rescue the cleantech industry. Frugal innovation, initiated from emerging markets to overcome resource constraints and address the needs of the "bottom of the pyramid," has attracted broad attention. The no-frill, cost-cutting, and resource-saving nature of frugal innovation has enabled many firms to create successful and affordable products. This paper delves into details of how various organizations harness the practice of frugal innovation to develop affordable cleantech or green products. The research found that a range of organizations successfully discovered neglected needs from underserved consumers or environmental concerns, made good use of natural or inexpensive resources locally available, incorporated simplicity in their product design, and took into account the affordability and other requirements altogether to design affordable and sustainable green products. Clean technology firms are advised to harness frugal thinking and design in their products to ensure the longevity of the industry.