Many changes in business drivers are now affecting power-producing companies. The power market has been opened up and the number of locally operating companies has increased. At the same time the need to utilize locally produced biofuels is increasing because of environmental benefits and regulations. In this situation, power-producing companies have on focus their in-house skills for generating a competitive edge over their rivals, such as the skills needed for developing the most economical energy investments for the best-paying customer for the local biomass producers. This paper explores the role of optimization in the development of small-sized energy investments. The paper provides an overview on a new design process for power companies for improved use of in-house technical and business expertise. As an example, illustrative design and optimization of local wet peat-based power investment is presented. Three concept alternatives are generated. Only power plant production capacity and peat moisture content are optimized for all alternatives. Long commercial experience of using peat as a power plant fuel in Finland can be transferred to bioenergy investments. In this paper, it is shown that conventional technology can be feasible for bioenergy production even in quite small size (below 10 MW). It is important to optimize simultaneously both the technology and the two businesses, power production and fuel production. Further, such high moisture content biomass as sludge, seaweed, grass, etc. can be economical fuels, if advanced drying systems are adopted in a power plant.