Spirulina has been studied due to its commercial importance as a source of essential amino acids, protein, vitamins, fatty acids etc. Most of the culture systems in use today are open ponds. The new approach proposed in this paper is to use the geothermal water as a medium for microalgae cultivation. Poland has beneficial conditions for wide geothermal use, as one of the environmentally friendly and sustainable renewable energy sources. In the planned research, geothermal water could be used to prepare microalgal culture medium, to heat greenhouses with bioreactors used for the growth of Spirulina, to dry the obtained biomass, as well as to heat the ground in foil tunnels. Using geothermal water gives the possibility to produce algae in open ponds covered with greenhouses and to cultivate plants during winter. The obtained algae can be used for the production of algal bio-products (e.g. homogenates), having the potential application in plant cultivation.