Combined Heat and Power or CHP is also known as cogeneration. As its name indicates, CHP is the process of simultaneously producing electrical energy and thermal energy in one system. Especially in greenhouse horticulture, the advantages of combined heat and power can be significant.
Greenhouse crops require a few basic ingredients: light, temperature, carbon dioxide, water and nutrients. This is needed for the process of photosynthesis. Enhancing the photosynthesis can be done by adding more of these ingredients to the greenhouse. Cogeneration can take care of three of these important elements required for photosynthesis.
Firstly, the electricity produced by the CHP system, can perfectly be used for the electricity demand of installed grow-lights. The production of electrical energy through cogeneration can make for a solid business case when electricity prices are high and / or the power demand from the grow-lights is high. The option to sell excess generated energy to the community grid is another feature that makes Combined Heat & Power an option worth considering for a greenhouse project.
Besides the production of electrical power, CHP generates heat. Similar to a combustion engine in a car, a cogeneration plant is water cooled. For the horticultural appliance, the cool-water of the engine is efficiently used to heat the greenhouse. In operation, the Combined Heat and Power system will be creating a high amount of additional heat. Because the heat may not be used immediately into the greenhouse, the excess heat might be stored into a so called buffer or heat storage tank.
Lastly, the reason that Combined Heat & Power is highly efficient in greenhouses, is due to the plants’ requirement of CO2. A by-product that is normally useless, is of great value to each greenhouse operation. The combustion of natural gas leads to exhaust fumes that provide for relatively clean Carbon Dioxide which are used as fertilizer for the crops.
In short, Combined Heat & Power can supply a greenhouse operation with heat, electricity and with valuable CO2 for the crop. CHP is therefore a highly energy- efficient system which can make for a standalone business case. To determine whether it will be suitable at your location to operate a cogeneration engine on your greenhouse premises we can assist in making a small pre-feasibility to determine the investment and the pay-back period.