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

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...

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Veröffentlicht in:Heliyon 2021-12, Vol.7 (12), p.e08608-e08608, Article e08608
Hauptverfasser: Chiriboga, Gonzalo, Capelo, Santiago, Bunces, Pablo, Guzmán, Carla, Cepeda, Jonathan, Gordillo, Gilda, Montesdeoca, Diego E., Carvajal C, Ghem
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Sprache:eng
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Zusammenfassung: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 m2 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. •Geothermal applications are still marginal in South America.•Tropic's temperature changes make the system shift from heating to cooling constantly.•Geothermal conditioning of a greenhouse in the Andean region of Ecuador is feasible.•65% of the electricity required is used for cooling due to the COPs.•Fuel subsidies in Ecuador make LCOH less competitive. Geothermal conditioning; Greenhouse; Heat pump; LCOH; Ecuador; Capacity factor.
ISSN:2405-8440
2405-8440
DOI:10.1016/j.heliyon.2021.e08608