REPORT 1

  
 

The Greenhouse Use of Waste Heat of Transitgas AG's Gas Compression Station (GVS) at Ruswil (Switzerland)

Pilot Project to Run a Greenhouse with Temperate and Subtropical/Tropical Climate Conditions
  By Dr.Johannes Heeb*, Felix Huber*, Philippe Wyss**, Wolhusen, Switzerland
  * Dr. Johannes Heeb GmbH
Bahnhofstrasse 2
CH-6110 Wolhusen, Switzerland
Tel: +41 41 490 40 81; Fax: +41 41 490 40 74
  ** Centre for Applied Ecology Schattweid
CH-6114 Steinhuserberg, Switzerland
Tel: +41 41 490 17 93; Fax: +41 41 490 40 75
   
 

1. Present situation

  A study commissioned by the Transitgas AG shows that the use of greenhouses proves to be an interesting possibility for the Rottal-Wolhusen region (Switzerland) to utilise the waste heat from the Transitgas AG's gas compression station (GVS) at Ruswil.
Experimental greenhouse
As an initial step, an experimental greenhouse of approx. 1500 m2 was built in 1999. A pilot phase runs over a period of 2 - 3 years (from 1999 - 2001). The results of this phase will be the basis for a possible expansion of the project.
Picture: Tropical greenhouse Ruswil.: Tropical fruit trees with Tilapia fish-tanks in the background. (Johannes Heeb, 30.8.99).
   
 

2. Arguments for the proposed system
Economic, environmental and landscape-protection arguments support the project approach
A part of the greenhouse is run as a polyculture system (cf. also the following diagram). Economic, environmental and landscape-protection arguments speak for this approach: The cultivation of "niche (speciality) products" as subtropical as well as tropical fruit and vegetables could be profitable and stimulate the region's economic development. Polyculture systems aim, as far as possible, at maximum productivity and make use of complete nutrient and energy cycles; they are also known for their "cascade use" of nutrients and energy which makes them both productive and environmentally friendly. Thanks to the high productivity of a polyculture, the greenhouse area can be kept to a minimum for reduced impact on the surrounding landscape.
  Besides the polyculture, another part of the greenhouse is operated in a conventional manner and under temperate climate conditions. In a later stage, however, it might be possible to develop and apply polyculture systems in this part as well.
   
 

3. Pilot greenhouse: reasons for the combined use of temperate and subtropical/tropical climate zones for growing fruit and vegetables
 
50 % of the area
with temperate climate
50 % of the area with
subtropical/tropical climate
Reasons:
  • Production techniques and products are known.
  • Expenditures for the necessary infrastructure are average.
Reasons:
  • There is no competition for existing bidders.
  • Innovation makes access to new funds (e.g. Regio+) possible.
  • New impulses for the region
  • "Niche production" is possible.
The combined set-up of subtropical/tropical and temperate climate zones increases the chances for success during the trial phase.
Project is unique for Switzerland
 The project is unique for Switzerland. Therefore, it could trigger interesting impulses for the Rottal-Wolhusen region.

The suggested systems are not only advantageous to the regional development. They also offer the interesting possibility to be combined with the technical utilisation of waste heat, e.g. the production of electricity and long-distance heating systems. This is, because greenhouses can also make use of the exergetically less valuable low-temperature fraction of waste heat and can at the same time be used as energy-buffer systems. There is also a great flexibility as far as the setting up of the greenhouses is concerned - a step-by-step approach is possible; the same also applies to a possible reduction in size or disassembly.
   
 

4. Technical aspects
Established techniques
 Greenhouse systems can be set up with available and well-established techniques.
Complementary use in combination with the technical utilisation of waste heat
 They can further be of complementary use in combination with the technical utilisation of waste heat; In combined application systems, the exergetically valuable high-temperature fraction of waste heat can be utilised in long-distance heating systems and systems for the production of electricity etc., and the remaining low-temperature fraction can be applied in greenhouses.

The aquaculture systems within the greenhouses represent an interesting energy-storage and buffer system and allow a great tolerance of a fluctuating supply of waste heat.
   
 

5. Evaluation of potential risk
Risk potential is negligible
With proper handling, the risk potential in building and operating these greenhouses is negligible. Investigations and clarification regarding ecological as well as epidemiological aspects have already been carried out.
   
 

6. Description of the system in the pilot greenhouse
Area of greenhouse: 1444m2
The pilot greenhouse covers an area of approximately 1444 m2. This area is used for a greenhouse section with a temperate climate zone which includes an area for educational and demonstration purposes (approx. 722 m2) and a greenhouse section with a subtropical/tropical climate (approx. 722 m2). The greenhouse consists of double-layered glass panes and a light metal structure. Its location was decided upon to be at the farm of Mr. J. Disler, situated north-west of the Gas Compression Station at Ruswil.
Liquid manure from farm as nutrient input
 Liquid manure from this farm serves as a nutrient input for the total greenhouse system.
Educational and demonstration section
Subtropical and tropical greenhouse section
 The subtropical and tropical greenhouse section is provided with the necessary infrastructure for the polyculture. A separation was installed for the pre-treatment of the manure used as nutrient-input. Here the liquid and solid fractions of the manure are separated.
Pre-treatment steps
 The solid fraction is beeing composted at the composting site (area: approx. 60m2) and processed into fertiliser. Further, mushrooms and earthworms will be cultivated there. The produced fertiliser can be used for the plants growing in the soil of both sections of the greenhouse.

The liquid fraction resulting from this treatment is still rich in nutrients and is conducted to shallow water basins where floating water plants are grown (total area: 10 m2, depth: 0.25 m). These floating plants serve in turn as food for fish in the attached fish tanks. At the same time special kinds of vegetables can be cultivated here. The shallow water basins will be suspended above the fish tanks.
Integrated aquaculture ponds
 The fish tanks (integrated aquaculture ponds) have a total area of 50 m2 and a depth of 1.5 m. In these tanks, tilapias, a subtropical and tropical fresh water fish with a high market value are raised. The water from the fish tanks will is conducted to the shallow water basins and cleaned there.
Picture: Tilapia breeding colony in tropical greenhouse Ruswil (Johannes Heeb, 30.8.99)
Soil cultivation area
 The soil cultivation area is with its 600 m2 the largest section. Here subtropical and tropical fruit and vegetables are produced. Rapidly growing plants, bushes, or trees with a maximum height of 4-6 m and with a large yield are required for the production, for example papaya, mango cumquat, annnona, passion fruit, guava, litchi, cape gooseberry, tree tomatoe etc.. The areas between the fruit plantations will be used for the production of vegetables and spices.
Minimal use of water from municipal water supply
 The need for water from the municipal water supply should be minimal. To reach this goal, a rainwater-storage tank with a volume of 150 m3 was installed in support of the water circulation.

The following diagram illustrates how the subtropical and tropical polyculture system functions. The diagram shows the structure of the system, not the proportions of the single areas involved.
 

7. Market interest
Economic interest in subtropical and tropical products which are produced locally
 An initial market analysis shows that there is an economic interest in subtropical and tropical products which are produced locally and in an environmentally friendly manner.

In the start-up phase, gastronomy with emphasis on quality and businesses in speciality and gourmet products, as well as local village shops, are expected to be the initial buyers of these products. During the pilot phase - from 1999 - 2001 - it will be necessary that the people involved in the project develop further customer groups or market chains. Profitability of production is certainly guaranteed due to the advantageous availability of energy and a year-round growing season.
 
  Info on Heeb GmbH: http://www.heeb-gmbh.ch
Info on greenhouse: http://www.tropenhaus-ruswil.ch