Article. Energy in fokus - from Kyoto to Copenhagen. - AgroTech

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oof vents on the sheltered side. Humidity is controlled by the ClimecoVent system. An air-handling unit for heat recovery (the Regain unit) is connected to an air distribution system with perforated flexible pipes installed under the cultivating systems. This enables dehumidification by means of heat recovery. The greenhouse is equipped with pipe rail heating and wall heating. Forced-air heating/cooling units are installed over the aisle. The greenhouse is also equipped with a single shade cloth (LS 10). This concept is developed by Climeco Engineering and Maurice greenhouse builders. Energy efficient climate control Within semi-closed greenhouse concepts, an energy efficient climate control leads to further reduction in energy consumption and/or increase of production. Possibilities are: temperature integration, drop strategies, reduction of transpiration by reduction of leaf area, higher setpoints for relative humidity and using diffuse light. New growing strategies are currently developed for several crops. The aim of such concepts is to reduce energy consumption dramatically without production losses. In the new growing strategy for tomato e.g. the energy consumption has to drop from 40m 3 to 26 m 3 gas per m 2 greenhouse area. This is done by high insulation using a double screen. The first screen is a transparent screen, which is closed until 250 W/m 2 outside radiation. The second screen is aluminized and highly insulating. It is closed when the outside temperature is below 8 o C. The heating temperature is lowered by 1 o C, the ventilation setpoint is Jukka Huttunen, Biolan Oy, PL 2, FI- 27500 Kauttua, Finland, jukka.huttunen@biolan.fi increased. Above 85% humidity the ventilation is opened. It seems that the goal can be reached in a demonstration trial. Other concepts are developed for other crops. There are several possibilities to decrease energy consumption in greenhouse horticulture in the future. The challenge is to reach that with low-cost solutions. More conditioned greenhouse are certainly necessary in the future. Semi-closed greenhouse concepts are permanently in development in order to optimize the systems concerning costs and performance. In order to apply new greenhouse concepts and growing strategies into horticultural practice cooperation and active exchange of knowledge between growers, horticultural industry, extension service and research is necessary. Novarbo – Closed Greenhouse Cooling Keywords: High yield, CO 2 , condensation Abstract High CO 2 during high light conditions is possible in a closed greenhouse. Closing also helps plant protection and prevents the heat loss, which occurs when ventilating excess humidity, especially when using artificial lightning in a cold climate. The result of closing is increased yield and decreased energy use per product. Novarbo is a novel cooling method for closed greenhouse. Inside the greenhouse is a water droplet curtain, which transfers the energy directly from the warm and humid greenhouse air to the cooling water by condensation of the latent heat and conductivity of the sensible heat. Only the heated water is then led out, where an evaporator sprays water through outside air, evaporating and thus cooling the water, which is then pumped back to cool the greenhouse. Two years of commercial use shows the coefficient of performance in inside cooling (COP) was 60 –200, which is very high, compared to normal heat pump COP 3-8. The Finnish Agrifood Research center has growing results with cucumbers: better crop +(25-41) %, with cut roses: + 25 % with tomatoes +10 %. This method maximizes the growth and minimizes the environmental impact, especially in wellequipped greenhouses. 38 ENERGY IN FOCUS
Janni Bjerregaard Lund, Ole Skov and Bent S. Bennedsen, AgroTech A/S The intelligent greenhouse concept The vision behind our concept is a 60% reduction in energy from fossil fuel when producing potted plants in a one layer greenhouse and without any negative effect on the quantity or quality of the produce. This objective will be achieved through a combination of; • Improved strategies for climate control • Extraction of surplus heat and storing it in ground water reservoirs • Improved curtain systems • Introduction of a novel wireless sensor system • Further improvements of the climate control software, in order to utilize the potentials in the new sensor technology, heat extraction, LED lighting, and curtains. The concept is being implemented and tested on the greenhouse production plant “Hjortebjerg” located 23 kilometres north-west of Odense at Funen Island (Latitude 55° N). The main production is potted Euphorba milii Des. Moul. The first step was carried out in 2007 and consisted of a climate check. This involves construction of a mathematical model, which simulates the greenhouses, and computes the energy consumption at different climate control strategies. The result was that by introducing dynamic climate control, an energy reduction of at least 21% could be obtained. During 2008, the actual reduction was 35%, from 375 kWh/m 2 in 2007 to 241 kWh/m 2 in 2008. Calculations have shown, that the irradiance, received by a greenhouse over the year, is twice the energy requirement during the same period. However, there is a surplus during the summer, which is lost through ventilation and a deficiency in the winter, which is supplemented by heating. In our concept, we extract heat from hot air, collected below the roof ridge of the greenhouses, and store it in groundwater reservoirs. During the summer, ground water of 10 o C is passed through an air to liquid heat exchanger, which raises the water temperature to an average of 30 o C with a maximum of 35°C. The water is then pumped back into the ground water reservoir, at a depth of 40 m, where it will maintain its temperature, albeit with a slight loss, until winter. The process is reversed during winter by pumping the water up and cooling it by means of heat pumps. This generates 70 – 80 o C water for heating the greenhouses. The system is not able to fully extract heat on hot summer days and will be comparable to what is known as the semi-closed greenhouse. The combined effect of optimized climate control and heat storage will be a 50% energy reduction. Further reductions will be achieved by introducing new curtains and improved sensor technologies for more accurate climatic information and further improved climate control. A system of two layers of curtain will be introduced to improve the insulation and thereby reduce heat radiation. The “NIR curtain” and a LS16 curtain (AB Ludvig Svensson) will be installed in the demonstrations house at Hjortebjerg. The new sensor system, which is being developed by Danfoss IXA Sensor Technologies, will comprise a relatively large number of small, wireless sensors, which will measure temperature, relative humidity, CO 2 level, radiation and leaf temperature. The sensors will be located in the foliage of the plants, and hence give more accurate and detailed information about the actual conditions, which the plants are experiencing. This will permit the grower to fine tune his climate control, and thus reduce the energy input. The projects will continue until 2012, by which time, we are confident that the objective of a 60% energy reduction will be achieved for the Hjortebjerg plant. Further, based on the knowledge acquired during the projects, other greenhouse production plants will be able to achieve the same amount of reduction of energy and CO 2 emission. ENERGY IN FOCUS 39
Page 1 and 2: ENERGY IN FOCUS EnErgy in Focus - F
Page 3 and 4: Jesper Mazanti Aaslyng Head of Depa
Page 5 and 6: nursery ditions for the plants are
Page 7 and 8: greenhouse If screens are used almo
Page 9 and 10: sis is routine, but it is impossibl
Page 11 and 12: Jens Møller Jensen, CTO, Danfoss I
Page 13 and 14: Pottemaskine Pottemaskinen består
Page 15 and 16: A C D ACF F ENERGY IN FOCUS 15 D C
Page 17 and 18: Anker Kuehn, AgroTech, ank@agrotech
Page 19 and 20: Anker Kuehn, AgroTech, ank@agrotech
Page 21 and 22: Energiforbrug Dækmaterialer • Gl
Page 23 and 24: Flemming Ulbjerg • Chief consulta
Page 25 and 26: Figure 2. Dynamic climate control t
Page 27 and 28: The World of Dalina® 2010 Midi+ Ma
Page 29 and 30: Pindstrup products are sold worldwi
Page 31 and 32: carbon footprint CC Container, has
Page 33 and 34: Mini symposium / workshop Intellige
Page 35 and 36: Program Tuesday October 6 9.30 Open
Page 37: (semi)closed greenhouses with cooli
Page 41 and 42: Timo Kaukoranta and Juha Näkkilä,
Page 43 and 44: Martin Lykke Rytter Jensen and Bo N
Page 45 and 46: Ole Bærenholdt-Jensen, Advisor, Ho
Page 47 and 48: 1 S. Lambrecht, s.lambrecht@fz-juel
Page 49 and 50: Jens Møller Jensen, CTO, Danfoss I
Page 51 and 52: Eva Rosenqvist 1 , Anker Kuehn 2 ,

Article. Energy in fokus - from Kyoto to Copenhagen. - AgroTech

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