The invention concerns a system for generating energy from biomasses and producing vegetable substances, comprising a synthesis gas generator (3) with an intake for biomass, an electricity generator (4) starting from the synthesis gas, connected to said synthesis gas generator (3) and a greenhouse (10) suitable for the production of vegetable substances. The system is characterised in that the electricity generator (4) is suitable for generating, from the oxidisation of synthesis gas, thermal energy, electricity, carbon dioxide and water as residues of such oxidisation, and that the greenhouse (10) is connected to the electricity generator (4) to receive therefrom thermal energy, electricity, carbon dioxide and water.