LIFE CYCLE ASSESSMENT OF DIFFERENT HEATING SYSTEMS FOR GLASSHOUSE TOMATO PRODUCTION IN FLANDERS, BELGIUM

Nowadays policy makers focus more and more on climate change, energy use and other environmental threats. This urges the implementation of corresponding strategies into the management of production systems like greenhouse horticulture. In order to produce more sustainable one must know which strategies implicate a high environmental burden and respective costs. A life cycle assessment (LCA) allows such a quantification of the environmental performance of a product regarding the comprising production subprocesses. Due to a high energy demand in Flanders’ glass greenhouse tomato production, this LCA assessed and compared the environmental impact of three applied heating systems: a traditional gas boiler, oil boiler and cogeneration (also combined heat and power, CHP) system. The inventory of inputs and impacts (outputs) were expressed in terms of 1 ton of produced tomatoes. Results show to what extent the different systems contribute relatively to sustainable management concerning emissions and cumulative energy demand. In most impact categories the comparative LCA indicated a preference for the cogeneration system, but this only due to a social credit of avoided electricity production by power stations. However, regarding ozone depletion and photochemical oxidation, the gas boiler generated a lower impact, even though differences with the former are small. The oil boiler system has an overall unfavorable impact as the incineration of oil has a higher pollution potential compared to natural gas. Furthermore the CO₂ in the flue gasses cannot be recovered, making it necessary to produce additionally liquid carbon dioxide, creating an even higher burden on the environment.