Purpose <p>The increasing production of solids non-fat (SNF) from whey and ultrafiltration permeates in the cheese industry has led to negative externalities and costly management for plants, impacting their competitiveness and sustainability. This study evaluates the techno-economic performances of different upcycling scenarios of these by-products in the province of Québec (Canada).</p> Methods <p>The assessments are based on predictive analysis considering individual approach valorization in site and total volumes of by-products generated in four regions of Québec. Considering the presence of economies of scale, schemes have been developed utilizing three plant scales (small, medium, large) and a regional model, and various valorization scenarios for animal and human feeding, as well as biogas and bioethanol production. Economic indicators including unit cost price, net margin, break-even point, and payback period were calculated.</p> Results <p>Economic performance simulation results indicate good profitability for medium and large-scale plants when converting whey into high-value-added dairy ingredients, with profitability and cost varying according to the protein content of the whey ingredient. The production of high-protein whey protein concentrate (80% protein on a dry basis, WPC80) by large plants is more costly but more profitable due to its higher average market price. Large plants benefit substantially from the scale economies and have more valorization options compared to others. Nevertheless, the economic performance of small plants valorizing whey is very limited, with animal feeding as liquid whey representing the only viable option. Alternatively, a collective approach can be a good alternative, allowing them to valorize whey into bioethanol or methane under certain conditions, such as with public subsidies.</p> Conclusion <p>Our findings reveal the costs and benefits of various SNF valorization schemes and identify market opportunities for large and medium-sized plants. Economic incentives could be implemented to support individual and collective initiatives for whey and UF permeates valorization.</p> Graphical abstract <p></p>