Countertop Food Waste Dehydration Poses Climate Tradeoff between Transportation Savings and Electricity Use

Abstract

Organic recycling can be hindered by the high water content of food scraps—making transportation costly and greenhouse gas emissions intensive. One potential solution is drying these materials prior to transport, which also reduces volume and odor. However, this approach introduces a new trade-off, as the energy used for drying is also associated with greenhouse gas emissions. We conducted a life cycle assessment (LCA) to explore this trade-off in the context of electric countertop food dehydration technologies, which dehydrate kitchen scraps to reduce the weight of material transported while reducing particle size mechanically. Scenarios analyzed included home composting, centralized composting, landfilling, and countertop dehydration followed by either home or centralized composting. We used sensitivity analysis to evaluate how transportation-related distance and grid carbon intensity influence the climate impact of each strategy. Use of a countertop food dehydrator prior to composting was estimated to reduce the climate change impact of food waste management (CO2-eq kg−1 food waste) by 42–92% relative to landfilling, depending on the specific scenario. The comparison between composting scenarios with and without prior dehydration was sensitive to transport distance and the carbon intensity of the consumer's electric grid.