Increasing participation of alternative energy sources (including geothermal energy) in the domestic sector will improve the natural environment of Poland. Also current recognition of geothermal energy reserves and conditions of their occurrence in the Polish Lowlands point to possibilities for their industrial-scale utilization. This, is confirmed by detailed cost-effectiveness analyses based upon the standard assessment methods for investment projects (NPV, IRR) made for some tens of towns in the Polish Lowlands. An example of the possible localization of cost-effective geothermal installation is the Czarnkow project. (C) 2003 Published by Elsevier Science Ltd.