Planning takes place at different levels in society and for many reasons. Some planning models focus on values, e.g. resource planning models, others on costs which is especially relevant in project planning, and still others, e.g. models for business management planning work with money as the basis for the planning. Thus, the three concepts value, costs and money are fundamentally different in spite of the fact that they are expressed in the same units ($, pound, SEK, etc.) In this paper arguments are given that these concerts should be kept separate in planning models and, more generally, that different planning conditions call for different and often specific planning models. The particular characteristics of the field of bioenergy make these points even more relevant when applied to bioenergy activities rather than to more general planning. (C) 2000 Elsevier Science Ltd. All rights reserved.