Different renewable energy sources can be used for greenhouse heating, but several problems have to be solved before renewable energies can substitute fossil fuels. Possibilities and criteria are discussed.

The paper deals with the in situ experimental determination of the thermal properties of the underground soil for use in the design of borehole heat exchangers (BHE). The approach is based on recording the unsteady thermal response of a BHE that has been installed for the first time in Saudi...

Geothermal and solar heat can be directly converted into electricity by using thermoelectric generators. Perovskite-type metal oxides are potential materials to improve the efficiency of these devices. Cobaltates with p-type conductivity and n-type manganates are considered for the development...

Market penetration of renewable energy sources, such as geothermal energy, could be promoted even by small cost reductions, achieved through improved development design. This paper deals with optimization of the exploitation system of a low enthalpy geothermal aquifer, by means of the method of...

The main objective of the present study is twofold: (i) to analyze thermal loads of the geothermally and passively heated solar greenhouses; and (ii) to investigate wind energy utilization in greenhouse heating which is modeled as a hybrid solar assisted geothermal heat pump and a small wind...

Geothermal energy has been successfully applied in many district heating systems. In order to promote better use of geothermal energy, it is important to analyze the operation strategy of geothermal heating system. This study proposes a comprehensive and systematic operation strategy for a...

A reliable heat transfer model was developed to determine the performance of a double pipe heat exchanger retrofitted to an abandoned petroleum well. The proposed model is compared against an analytical heat transfer model and two numerical models, in order to determine the reliability and...

This article identifies and explains several attributes of geothermal energy. High exergetic efficiency due to a close temperature tie between geothermal energy and district heating and cooling was noted. Parameters governing the rational use and management of geothermal energy systems with...

Micro combined heat and power (CHP) plants operating through an organic Rankine cycle (ORC) using renewable energy are analyzed. The reference system is designed to produce 50kWe. The heat sources of the system are geothermal energy at low temperature (80–100°C) and solar energy. Two...

This paper presents the energy evaluation of the cross-flow vacuum membrane distillation (VMD) for three types of lab-fabricated polyvinylidene fluoride (PVDF) membranes and the commercial Westran S PVDF membrane. Membranes with the effective area 23.5cm2 are tested with distilled water and...