Πάνω Frame [668xX]

Combined heat and power production (CHP) systems, or simply “cogeneration systems”, can be used in greenhouse applications leading to significant benefits. Heat, light and carbon dioxide (CO2) all stimulate the growth of plants. Gas engines can provide these stimuli with high efficiency, producing a flexible supply of electrical power, heat and carbon dioxide as a by-product of the combustion of the fuel gas. Electrical power can be used to provide energy for the artificial lighting or can be exported to the grid, heat can be used for achieving the desired temperature within the greenhouse or stored as hot water for use when needed and finally the CO2 can be scrubbed and used to promote plant growth.

Benefits of CHP in greenhouses

 

  • Efficiency can reach 95%, thus leading to resource savings and maximisation of profits.

  • Provides power to grid at times of maximum demand, hence receiving highest power sale prices.

  • Time-independent supply of CO2 and heat through heat storage.

  • High quality CO.

 

Benefits of Carbon Dioxide supply in a greenhouse

 

Plants convert CO2 to carbon through photosynthesis and grow. Atmospheric air usually contains 350 ppm CO2. Optimal CO2 levels depend on the type of plant and generally lie above 700 ppm. With increased artificial lighting, as present in greenhouses, plants absorb even more CO2. If the greenhouse air is enriched with CO2, the temperature kept on a constant level and sufficient lighting, plant growth can be increased significantly, providing the corresponding economic benefits. When burning natural gas in a gas engine, approximately 0,2 kg of CO2 is produced per kWh of energy input. This CO2 quantity can be scrubbed from the exhaust of the engine and utilized in plant growth.

 

Exhaust Purification

 

The exhaust gas derived from the fuel combustion in the engine gets purified with special catalytic converters (SCR and oxidation catalytic converters) and then cooled down by a heat exchanger to approximately 55°C and supplied to the greenhouse for CO2 enrichment. Maximum safety for vegetation is ensured by the installed measurement devices that constantly measure the air quality level.

 

Optimized utilization

 

  • Efficient greenhouse application is possible with approximately 1 hectare (about 2.47 acres) or larger greenhouse areas.

  • CO2 fertilization is suitable for nearly all plant types

  • CO2 fertilization with simultaneously heat supply: dimensioning for 0.5 MWe/ha

  • CO2 fertilization with simultaneous heat supply and illumination: dimensioning for 0.35 MWe/ha

  • Illumination suitable for vegetables (e.g. tomatoes or peppers) and for flowers (e.g. chrysanthemums or roses)