Developing energy use and savings indices for Michigan greenhouses

Abstract

<b><sc>Abstract.</sc></b> Michigan ranks third in floriculture production output behind California and Florida[1]. There were 549 floriculture producers in Michigan in 2020. They have a distinct disadvantage like other growers in northern states, of having to extensively heat their facilities during the bulk of their operational season which occurs during the winter months. Michigan greenhouse operators have a limited range of information available to them that shows how their operations‘ energy use compares to other greenhouses that are of a similar size and growing evironment. Â The limited available information have focused more closely on individual areas of energy utilization rather than a more holistic approach that can be applied to any operation needing energy efficiency improvements [2]. The objectives of the development of these indices are to: 1) Compile certified ASABE/ANSI S612 type 2 energy audits that have been conducted on Michigan greenhouses; 2) Analyze the data to understand the energy usage and patterns as well as energy efficiency improvements for the greenhouse operations of similar sizes; 3) Deliver the information in a way that operators can apply to their own facilities. The Michigan Farm Energy Program (MFEP) has been conducting certified energy audits on Michigan greenhouse and documenting each operation's energy use, greenhouse size as well as proposed energy conservation measures (ECMs) with their potential energy savings and implementation costs. This information was used to create an energy use index and energy savings index for Michigan greenhouse operations. The energy use index is broken down into three operational size categories and shows two different metrics. The categories used to describe greenhouse operational square footage are: 1) small (4,000 to 25,000 sq ft), 2) medium (25,000 to 100,000), and 3) large (greater than 100,000 sq ft). These three size categories used were developed by Michigan State University Extension [3]. The two metrics for analysis are total energy consumed per sq ft of greenhouse operation broken down into these size categories and total energy use per size category. The analysis also breaks down areas of major energy usage and potential energy savings that can occur with recommended energy conservation measures. Improving energy efficiency in the identified areas of lighting, space heating, water heating and distribution, ventilation, weatherization, energy curations, and IR/IRC poly film have led to substantial potential energy savings on an annual basis.