To demonstrate hydrocarbon substitution and energy saving in a 2000 m2 greenhouse by means of an integrated energy system.
Energy saving depend on climatic conditions from 35 to 60% with statistic data. Payback time depend on greenhouses area. From 6 to 8 years.

The energy savings are achieved through the use of a heat pump, heat storage and thermal screens. Enthalpy from hot and humid air removed from the upper part of the greenhouse above the screen is transferred by means of the heat pump to low temperature water. This heated water is piped through the soil. It can also be used to heat mobile tables for cultures and to pre-heat water for watering. When the recovered heat is not required immediately it is stored in a large water mass.
A conventional boiler is used to provide the additional heat required, when necessary.
Cold air from the heat pump can be fed into the upper part of the greenhouse in order to maintain a sufficiently low temperature during the hours of maximum solar intensity.
The screens act either as thermal screens or shade screens depending on requirements and external climatic conditions. The internal climate is monitored and controlled by microprocessors in order to ensure continuous optimisation of conditions.