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Greenhouses conserve land and water while increasing crop production, making them an attractive system for low environmental impact agriculture. Yet, to achieve this goal, there is a need to reduce their large energy demand. Employing semitransparent organic solar cells (OSCs) on greenhouse structures provide an opportunity to offset the greenhouse energy needs while maintaining the lighting needs of the plants. However, the design trade-off involved in optimizing solar power generation and crop productivity to maximize greenhouse economic value is yet to be studied in detail. Here, a functional plant growth model is integrated with a dynamic energy model that includes supplemental lighting to optimize the economics of growing lettuce and tomato. The greenhouse optimization considers 64 different OSC active layers with varying roof coverage for 25 distinct climates providing a global perspective. We find that crop yield is the primary economic driver, and that crop yield can be maintained in OSC-greenhouses across diverse climates. The crop productivity along with the energy produced by the OSCs results in improved net present value of the OSC-greenhouses relative to conventional systems in most climates for both lettuce and tomato. In addition, we find common solar cell active layers that maximize greenhouse economic value resulting in guidelines for scaling up OSC-greenhouse design. Through this model framework, we highlight the opportunity for OSCs in greenhouses, uncover designs and locations that provide the most value, and provide a basis for further development of OSC-greenhouses to achieve a sustainable means of food production.
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Smart Glazing for Energy- and Cost-Efficient Greenhouse Humidity Regulation
Global food shortage demands significant progress in crop production. Greenhouses offer a solution for higher crop production by providing a controllable environment. Excess levels of humidity, however, encourage pests and diseases, drastically reducing crop yields. Traditional humidity control methods for greenhouses are expensive and energy-intensive. In addition to this, nonbiodegradable plastic covers cause massive white pollution. To tackle these concerns, we present smart glazing and sensors for greenhouse humidity regulation through both passive and active paths. We created biodegradable humidity-sensitive films by blending poly(ethylene glycol) (PEG) with cellulose acetate (CA). PEG/CA covers can automatically open for air circulation at high humidity, successfully demonstrating repeatable greenhouse humidity regulation to as low as 60% relative humidity. PEG/CA-based humidity sensors can actively accelerate air circulation and humidity reduction with repeated cycles at an even higher efficiency. Overall, our research introduces a low-cost, all-in-one, sustainable, and environmentally conscious solution for addressing the greenhouse humidity control challenges. Approximately, this solution can potentially achieve annual energy savings of up to 56.6 GWh for the U.S. if fully applied.
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- PAR ID:
- 10536551
- Publisher / Repository:
- American Chemical Society
- Date Published:
- Journal Name:
- ACS Sustainable Chemistry & Engineering
- Volume:
- 12
- Issue:
- 24
- ISSN:
- 2168-0485
- Page Range / eLocation ID:
- 9247 to 9256
- Subject(s) / Keyword(s):
- smart greenhouse glazing polymer blend humidity-sensitive sustainability automatic humidity regulation
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1021/acssuschemeng.4c02146
