Harnessing of geothermal energy for a greenhouse in Ecuador employing a heat pump: design, construction, and feasibility assessment

Abstract

Globally, the greenhouses' farming area comprises 500 000 ha, and they efficiently produce more than half of the vegetables consumed around the world. Nevertheless, high-yield crops tend to be incredibly energy-intensive. This study proposes designing and building a coupled geothermal heat pump for a 470 m 2 greenhouse in the Andean zone conditions addressing a requirement of 15 °C at night and 30 °C during the day. Firstly, the study determined the energy potential of the solar and geothermal sources employing actual measurements and contrasting the results with theoretical models. Then, it developed an energy balance in the greenhouse to size the geothermal heat pump using the vapor compression cycle. Finally, the comprehensive system was built and evaluated through the Leveled Cost of Heat (LCOH). The operation requires a potential of 29.56 and 65.76 kW for heating and cooling; this is technically feasible when running the system with a heating flow driven by an optimized temperature ramp of 1.64 °C h −1 . Also, the capacity factor (CF) shows that a lifespan between 12 to 14 years is required to reach acceptable LCOH when CF is as low as 0.45. Financially, it is necessary to foster customs exemptions to make it competitive versus more traditional sources such as electricity and LPG since the main components of the heat pump and the geothermal exchanger are not produced locally and represent nearly 70 % of the upfront costs.

Demand-Side Flexibility in Power Systems: A Survey of Residential, Industrial, Commercial, and Agricultural Sectors

“…The study concluded that the heat pump system can provide energy efficiency of 25% to 65% more than traditional combustion-based systems [148]. Technical assessment is provided to harness geothermal energy for heating/cooling systems of greenhouse farming in Ecuador [149].…”

Research on goaf treatment and geothermal comprehensive utilization technology in coal mining subsidence area

“…It should be noted that this work needs to determine the number of boreholes in combination with the load of the proposed building in the region. If the number of boreholes is insufficient, geothermal boreholes can be supplemented at an appropriate position, but it should be noted that the distance between the boreholes cannot be less than 5 m, otherwise it will cause cold and hot accumulation effect [51][52].…”

Improving the Economic Efficiency of Heat Pump Integration into Distillation Columns of Process Plants Applying Different Pressures of Evaporators and Condensers

“…The authors investigate the distribution of losses in the system over the elements of the system separately, and the equivalent CO 2 emissions of heating a greenhouse with natural gas and an HP system was compared. Chiriboga et al confirmed the possibility of designing and building a coupled geothermal HP [13]. Based on the results of the assessment of the energy potential of the solar and geothermal sources, the energy balance in the greenhouse was calculated to determine the parameters of the geothermal HP using the vapor compression cycle.…”