Residual heat exchange industry / greenhouse horticulture – Province of West Flanders

March 20, 2017
BS_Reference_Page_Horticulture

Client:  Province of West Flanders
Period:  2014 – 2015


Work

The central region of West Flanders, around Roeselare, is characterised by a mix of some large-scale industrial companies and agricultural activities. Greenhouse horticulture is part of the latter. Therefore, it was logical for the province of West Flanders to assess from a financial as well as a sustainability perspective, whether or not it would be realistic to exchange residual heat generated from industry with future greenhouse horticulture complexes. 3E carried out this feasibility study.

The starting point was the assessment of the existing residual heat in 6 industrial companies and a biomass-fired power plant. The steering committee ultimately selected 4 case studies for evaluating the feasibility. With regards to greenhouse horticulture, the crops taken into account were tomatoes, strawberries and lettuce. The different combinations of businesses and crops each provide a specific amount of ‘usable’ residual heat, in other words heat for which the timing of supply and demand coincides. For tomatoes, the required production of CO2 by the CHP-system has also been taken into account.

Analysis of the financial feasibility was based on specific return requirements for each party (the residual heat company, the greenhouse business and the heating company responsible for the heat network infrastructure and operations). The results indicate that the exchange, depending on the case study, could definitively be realistic. For the strongest case studies, the industrial company and the greenhouse can be up to a distance of a few miles apart.

It should be noted that the reference situation – heat- (and CO2-) production based on natural gas – is not a constant. On the one hand, the price of gas will determine what a greenhouse business will want to pay for the alternative, externally supplied heat. On the other hand, the current system of cogeneration certificates means that for the cultivation of fruiting vegetables, the CHP system should operate to its maximum. If, in the future, this form of operational support were to reduce, this would pave the way for the exchange of residual heat.