Postprint version. Published in Acta Horticulturae, Volume 797, January 1, 2008, pages 347-352. Copyright © 2008 International Society for Horticultural Science.The original publication is available at http://www.actahort.org.
In addition to the labor, energy and water consumption are the two main cost drivers in current greenhouse systems. Consequently, considerable effort is expended to conserve energy and water, and look for alternative energy sources, especially environmentally friendly renewable energy sources and technologies. Greenhouses in hot and arid regions also require large quantities of water for irrigation. Using proper technologies and environmental management systems can significantly change the energy and moisture dynamics of greenhouse production systems. This study aims to focus on reducing natural gas, electricity, and water consumption in semi-arid California greenhouses introducing renewable energy heat pump technologies to both open and confined greenhouses in California. The confined system has no external aeration and has no need for further water supply. It has a great potential to reduce the demand for natural gas, the load on the power grid, and the demand for irrigation water in greenhouse operations. It also allows plant protection without using chemical insecticides and the accumulation of carbon dioxide without aeration losses.
Bioresource and Agricultural Engineering | Horticulture