Consuming less energy and water. Innovative greenhouse concept
Glass greenhouses have a major disadvantage in countries with a harsh climate: they are not particularly efficient. Their poor insulation means that they quickly become too warm during summer and must be ventilated. In winter, they must be heated at all times because of the expansive glass surfaces. At the same time, plants such as cucumbers grow best when the temperature is a constant 27 degrees Celsius. “The problem with sunlight is that there is either too much or too little of it,” summarises Pasi Herranen, who jointly developed an innovative greenhouse concept with a team at Aalto University in Finland. Unlike conventional greenhouses made of glass or film, it is built from plywood and has neither windows nor heating. The extremely well-insulated walls save on energy and water. The plywood walls are 36 centimetres thick and vacuum-dried to ensure they are suitably airtight. They are also lined with a black rubber mass and covered with aluminium to create a surface that reflects light towards the plants. Plants consequently have the ideal conditions for growing vertically. Using LEDs, both the amount of light as well as the length of its rays can be regulated in a way that nurtures plant growth without additional heating, even during the frosty Finnish winter. According to the team, the greenhouse consumes about 50% less energy throughout the year than a conventional one made of glass, and can even emit warmth. Its water consumption is also 99% lower than traditional plant cultivation methods. Herranen originally developed the wall modules for office buildings and housing, only discovering by chance that they were also suitable for greenhouse plants after reading an article about cucumbers.