New Perspectives for Energy Savings in Agriculture

Preliminary notions.- - Preliminary notions.- 1. Fundamental criteria for a successful solar application.- 2. The (thermal) energy demand in agriculture.- 3. Solar radiation in the European Community — The identification of agro climatic zones.- I Applications of Solar Energy in Greenhouses.- 1: Process requirements — technological options.- 1. Traditional processes.- 1.1. Definition and importance of greenhouses.- 1.2. Production parameters.- 1.2.1. Photosynthesis.- 1.2.2. Respiration.- 1.2.3. Transpiration.- 1.2.4. Nutrition.- 1.3. Parameter dependency and periodicity.- 1.3.1. Light.- 1.3.2. Temperature.- 1.4. Transparent covering materials.- 1.4.1. Greenhouse effect.- 1.4.2. Covering materials.- 1.5. Screens.- 1.5.1. Shadow effect — light reduction.- 1.5.2. Screen materials.- 1.6. Effect of airtightness.- 1.6.1. Humidity.- 1.6.2. CO content.- 1.7. Cultivation techniques.- 1.7.1. Traditional Techniques.- 1.7.2. Nutrient film technique.- 1.7.3. Root zone warming.- 2. Energy conservation.- 2.1. Biological methods.- 2.2. Technical methods.- 3. Solar energy collection and storage.- 3.1. Short time storage (with greenhouse as collector).- 3.1.1. Thermal mass.- 3.1.2. Active short-term storage.- 3.2. Collectors other than the greenhouse itself.- 3.3. Long-term storage.- References.- 2: Present research within the E.C. on the application of solar energy in greenhouses.- 1. Criteria.- 2. Overview of projects on solar energy in greenhouses.- 2.1. Classification.- 2.2. Location of the projects described.- 2.3. Basic Descriptions.- 3. General conclusions for the greenhouse sector.- 3.1. Discussion of the listed research projects.- 3.1.1. Phytotechnical aspects.- 3.1.2. Covering materials.- 3.1.3. Thermal screens.- 3.1.4. Energy storage with greenhouse as collector.- 3.1.5. Energy storage with collectors other than the greenhouse.- 3.2. General evaluation.- Appendix to part I : Some specific research projects on greenhouses.- 1. Evaluation of different covering materials for greenhouse production of strawberries (Belgium).- 2. The biological effects of energy savings in greenhouses (Denmark).- 3. Evaluation of double-covered polythene greenhouse for early tomato production (Ireland).- 4. Comparison of the light transmission of greenhouses covered with twin walled sheets of polycarbonate and acrylic (England).- 5. Monitoring of a greenhouse with helioblocs based on solar energy (France).- 6. Greenhouse climatization by an earth-air heat exchanger (Greece).- 7. Development of a solar system for heating greenhouses (Greece).- II Applications of Solar Energy in Drying Processes.- 1: Process requirements — Technological options.- 1. Drying, why?.- 1.1. The problem : long-term conservation.- 1.2. Drying, a possible solution.- 2. Some aspects of drying process engineering.- 2.1. Characteristics of the drying air.- 2.2. The product.- 2.2.1. The product moisture content.- 2.2.2. Sorption and desorption isotherms.- 2.2.3. The 2 main stages in product drying.- 2.3. The drying set-up.- 2.3.1. Simulation.- 2.3.2. Characteristics of the drying set-up.- 2.3.2.1. Drier types.- 2.3.2.2. Instrumentation.- 3. Requirements and some adapted drying techniques for specific agricultural products.- 3.1. Grain.- 3.1.1. Introduction.- 3.1.2. Requirements in grain drying.- 3.1.3. Description of commonly used grain drying set-ups.- 3.2. Hay.- 3.2.1. Introduction.- 3.2.2. Description of a few commonly found hay-drying set-ups.- 3.3. Fruit.- 4. Evolution and alternative drying techniques.- 4.1. Production cost considerations.- 4.1.1. Energy cost.- 4.1.2. Investment costs.- 4.2. Ecological considerations.- 5. Incorporation of solar energy into the drying process.- References.- 2: Present research within the EC on the application of solar energy in the drying sector.- 1. The main research tracks.- 1.1. The “physical feasibility” track.- 1.2. The “economic feasibility” track.- 1.2.1. Choice of collector type.- 1.2.2. Choice of utilization factor.- 1.2.3. Choice of component dimensions and regulation systems.- 2. Overview of solar drying projects.- 2.1. Classification of the different research projects.- 2.2. Location of the projects.- 2.3. Basic project descriptions.- 3. General conclusions for solar drying.- 3.1. Considerations.- 3.2. Product-specific evaluation.- 2.1.1. Hay.- 2.1.2. Raisins.- 2.1.3. Grain.- 2.1.4. Others.- 4. Prospects for future research.- Appendix to part II : Some specific research projects on solar drying.- 1. solar drying of agricultural products (Greece).- 2. The use of solar air collectors for forage and cereal drying (Belgium).- 3. Solar heating for barn hay drying (United Kingdom).- 4. Development of a solar drier for wine lees (France).- 5. Solar energy for produce drying and milking parlour washing (Italy).- 6. The use of solar energy for bulb conditioning and soil heating (The Netherlands).- 7. Solar drying of grains (France).- III Applications of Solar Energy for Hot Water Production.- 1 : Process requirements — Technological options.- I. Biogas digester heating by means of hot water.- 1. Motives of the recent interest in biogas production.- 2. Description of the biogas production process.- 3. The digester temperature, parameter in the biogas production process.- 4. Digester temperature regulation techniques.- References.- II. Water heating for intensive aquaculture.- 1. The evolution of fish farming.- 2. Water temperature, an important parameter of the fish production process.- 3. Methods of hot water production.- References.- III. Floor heating for pigs (farrowing houses).- 1. Introduction.- 2. Recent evolution.- 3. Ambient temperature and microclimate manipulation as a means of ecological optimization.- 4. Methods of floor heating.- References.- IV. Hot water production for cleaning purposes in dairy farms.- 1. Introduction.- 2. Recent evolution.- 3. Hygienic standards and requirements.- 4. Hot water requirements.- 5. Methods of hot water production.- References.- V. Hot water for milk preparation on calf-rearing farms for veal production.- 1. Introduction.- 2. Recent evolution.- 3. The industrial type calf-rearing process.- 4. Nutrition.- 5. Milk preparation and distribution.- 6. The production of hot water.- References.- 2: Present research within the EC on the application of solar energy for hot water production.- 1. Overview of solar hot water production projects.- 1.1. Classification.- 1.2. Location of the projects.- 1.3. Basic project descriptions.- 1.4. Two examples of North American projects.- 2. General conclusions for solar hot water production.- 2.1. Discussion of the individual applications.- 2.1.1. Solar heating of a manure digester for production of biogas.- 2.1.2. Solar heating of fish farms.- 2.1.3. Solar assisted floor heating in farrowing houses.- 2.1.4. Solar heat for hot water use in dairy farms.- 2.1.5. Solar heat for milk preparation.- 2.2. Discussion of some practical and specific issues in the solar water-heating sector.- 2.2.1. The investigation of system efficiency.- 2.2.2. System economics.- 2.2.3. Socio-economic acceptability.- 3. Prospects for future research.- Appendix to part III : Some specific research projects on solar hot water production.- 1. Solar energy to accelerate cattle manure digestion (Italy).- 2. The use of solar energy for heating circulating water for eel- and carp breeding (The Netherlands).- 3. The use of solar energy for floor heating in a farrowing house (Belgium).- 4. Solar domestic hot water production and solar heating of a farrowing house (Germany).- 5. The use of solar energy for hot water production for a dairy farm (The Netherlands).- 6. Appraisal of a solar water heater for Bradmores farm dairy at Seale Hayne College (United Kingdom).- 7. The use of solar energy for hot water production on a calf-rearing farm (The Netherlands).- Addendum : Reporting formats.- 1. Basic descriptions.- 2. Detailed descriptions.