ABSTRACT
Integrated energy management entails energy conservation, energy mixture, and environmental considerations. Energy conservation is the practice of reducing energy use as a way of extending the lifetime of our fossil-fuel supplies, of being less wasteful, and of reducing our environmental impact. Personal choice and increased efficiency are the two parallel pathways for effective energy conservation. While using more efficient lighting fixtures, cogeneration systems or high efficiency boilers in our greenhouses are some of the examples of energy conservation via personal choice, developing more efficient lighting fixtures, cogeneration systems, or high efficiency boilers form the technical fix, that is, the increased efficiency.
In order to provide economically optimal microenvironments for plant growth, greenhouse operations can use or control the number of glazing layers, infrared inhibited double poly glazing, sidewall, end wall, and foundation insulation, energy curtains to reduce long-wave radiation losses at night, different shading devices to control incoming solar radiation, energy efficient lighting systems, reduced ventilation rates, evaporative coolers, variable speed pumps and fans, and high efficiency condensing boilers or flue gas condensers to extract waste heat that would otherwise be released to the environment and wasted. In addition, heat pumps hold great promise for reducing winter heating and warm weather cooling energy requirements, especially through semi-closed or closed greenhouse operations. Greenhouses will keep using conventional energy sources for the foreseeable future while incorporating more alternative energy sources in their energy mix and improved energy collection and storage technologies. Paying special attention to energy conservation measures certainly help growers to maximize energy savings and to make their operations more sustainable. However, conservation and sustainability require a multifaceted approach, and there is an additional dimension to energy use and conservation, the environmental dimension. In the years to come, energy investments will increasingly be determined by three factors: using energy more efficiently, improving competitiveness, and protecting the environment. Hence, this chapter not only covers the conservation techniques and technologies available for greenhouse growers supported with numerical examples but also dives deeper into the environmental dimension of commercial greenhouse operations in an effort to convert the global greenhouse industry to a fully sustainable net energy generating industry.
