Comparative Cost-Effectiveness Analysis of an Automated Home Hydroponic System

This study presents a comparative cost-effectiveness analysis of a custom-engineered automated home hydroponic device (the Display Unit) for fresh basil (Ocimum basilicum L.) production relative to retail purchasing, assessed from the end-consumer perspective. A framework incorporating unit production cost (UPC), return on investment (ROI), and payback period (PBP) was applied across a 61-day cultivation trial across five prototype units, under two device-price scenarios (prototype: 4,990.11 €; estimated market price: 3,911.40 €) and two retail segments (standard: 27.25 €·kg-1; premium: 57.39 €·kg-1), with and without food waste rate (FWR) correction. UPC under the market-price scenario reached 90.20 €·kg-1, exceeding the standard and premium references by 231% and 57%. ROI was negative across all analytical variants (-42.48% to -153.21%), with PBP undefined under the standard segment and exceeding the device lifetime under the premium segment. Threshold analysis confirmed that cost-competitiveness against the standard segment is unachievable through single-parameter optimisation. Heatmap sensitivity analysis demonstrated that the Display Unit already operates within the cost-competitive zone at the observed yield level under the premium segment with FWR correction and achieves full cost-competitiveness upon yield optimisation. FWR correction improved ROI by 14–37 percentage points, confirming the harvest-on-demand principle as a genuine cost advantage.