Economics and greenhouse gas balance of distributed electricity production at sawmills using hermetic turbogenerator

摘要

This article focuses on greenhouse gas (GHG) emissions reduction and on the economics in renewable electricity production at sawmills. Electricity production application in this study is a hermetic turbogenerator (HTG). The HTG is a small-scale steam turbine-generator unit of compact size that achieves high efficiency. The paper studies GHG emissions and the economics of HTG use in sawmills using life cycle assessment methodologies. Small- and large-scale HTG processes are studied in three scenarios. Sawmills produce large volumes of biomass by-products which are mainly used to produce heat needed in lumber dryers. However, due to remote location of sawmills there may be no use for excess biomass. HTGs can be used to produce electricity in addition to heat (CHP), which may help to increase renewable electricity production in sparsely populated areas. It is concluded that from the economic perspective HTGs may be an attractive option but financial viability is dependent on energy prices, required investments, and by-product value. From the climate change perspective, electricity production with HTGs may be a good option if there is excess biomass sources available. (C) 2015 Elsevier Ltd. All rights reserved.