In conventional greenhouse crop production the high level of energy input conflicts with international agreements on reduction of CO2 emission. To reduce absolute energy consumption, energy friendly greenhouse systems have to be designed. If today's available technology is applied energy saving will be too low to meet the standards in future. Therefore, new technology has to be developed on aspects ranging from improving the greenhouse insulation and light transmittance to climate conditioning and control and energy management. An important aspect is that the production system is converted from a production-driven to a consumer-oriented activity. Modelling and information technology are important aspects in the developments in interaction with other disciplines.