Innovative uses of renewable energy sources in the agricultural sector on the island of Crete, Greece

Although Crete is an island highly utilizing renewable energy sources (RES) for heat and power generation, their further applications in agriculture would result in many socioeconomic and environmental benefits. The use of renewable energies integrated in greenhouses in Crete is nowadays rather limited, and it could be increased in the future since the resources are abundant and the technologies are mature, reliable and cost-effective. Solar energy, solid and gaseous biomass, and low enthalpy geothermal energy could be used in order to provide heat, cooling and electricity to greenhouses to cover part or all of their energy needs. The positive impacts of their use include: additional income to the farmers, a reduction of greenhouse gas emissions due to energy use in them, an increase of employment in the local community and a decrease of energy dependency in Crete.The establishment of zero CO₂ emissions greenhouses due to energy use in Crete is currently feasible and cost-effective with the use of the existing renewable energies being available on the island. Unexploited renewable energy sources like landfill gas in Crete can also be used effectively for heating them. Biomass is currently used mainly for heat production in Crete, but new applications could be realized in the future including power generation and the production of biofuels. Olive kernel wood, a byproduct of the olive kernel oil producing industry, is extensively used in Crete for heat production. Besides heat generation, it could be used for the co-generation of heat and power and this process could be profitable under some conditions. Olive kernel wood could also be used as a raw material together with olive tree prunings for the manufacture of wood pellets in Crete. The work included in this thesis investigates various innovative uses and applications of sustainable energies in Crete, Greece, which could contribute to the promotion of energy sustainability in the agricultural sector of the island