The selected farming enterprise has a functioning greenhouse with the area of 2,000 m2 which can potentially be expanded to 20,000 m2. The farmer specializes at growing vegetables, such as tomato, cucumber, eggplant and bell pepper, which require a temperature regime in the range of 16-19 degrees Celsius above zero. The farmer has limited access to gas or diesel as sources of heat during autumn and winter. Although he has access to electricity and coal, it is unprofitable for the farmer to rely on them as main sources of heating. Furthermore, the use of coal-based heating leads to greater environmental damage. As a result of this, the growing season for the farmer is limited to summer.