SBIR-STTR Award

Greenhouse farming is an absolute necessity to revive and create local agriculture businesses in northern "climatically challenged" regions with short growing seasons. Controlled Environment Agriculture (CEA) has made significant strides in greenhouse farming technology. State of the art CEA farming utilizes direct control of lighting, temperature and carbon dioxide in a hydroponics environment.Providing adequate amounts of photosynthetically active radiation (PAR) has been shown to increase greenhouse production capacity to a level capable of supporting large market demand. The challenge for northern markets is to implement such supplemental lighting systems at a cost that makes CEA greenhouse farming competitive with large out of state farm and ship sources. For this SBIR effort, Cycloptics proposes to combine energy efficient lamps with Cycloptics' patented optimized reflectors to create a luminaire that will produce significant lighting energy and cost savings. With Cycloptics' technology, light from such lamps can be precisely controlled to create a highly uniform distribution over large arbitrary target patterns. It is the combination of target efficiency and lamp energy efficiency that yields the energy and cost savings for the proposed luminaire. Initial estimates indicate the new luminaire technology could achieve energy efficiency gains of 25 to 40% relative to existing growth chamber lighting. With the proposed lighting technology, year-round greenhouse agriculture could become economically more viable even for rural northern climate zones. If cost and energy efficiency gains can be demonstrated, the benefits align with Specific USDA goals. These include enhancing the international competitiveness and sustainability of rural farm economies by reducing costs of locally grown greenhouse produce to or below the cost of imported produce; support increased economic opportunities and improved quality of life in rural America from jobs created and associated with the greenhouse vegetable production industry; and enhancing the protection and safety of the agriculture and food supply by increasing local production of food that is easily traceable and better regulated by government entities. OBJECTIVES: The primary goal of Phase I will be to quantify the benefits of Cycloptics advanced HID (High Intensity Discharge) reflector designs over existing fluorescent fixtures in the growth chamber application. To achieve this goal, a prototype luminaire using a Cycloptics reflector will be designed, fabricated and tested. The benefits of the new reflector will be measured in terms of raw lighting energy efficiency and in terms of bottom line cost efficiency for lettuce growth. By the end of Phase I, an optimized luminaire reflector design will have been established for field trials in Phase II. To achieve success in Phase I, the following technical objectives will need to be accomplished. 1. Establish a baseline growth chamber model. This objective results in a calibrated computer model of an existing chamber that is based on real world lighting data. Questions that will be answered include: a) What are the model parameters needed to describe the existing chamber b) What is the overall energy efficiency of the existing chamber c) What portion of the energy efficiency is related to PAR (Photosynthetically Active Radiation) 2. Design HID luminaire for the growth chamber. This objective produces an HID based luminaire capable of replacing the fluorescent fixtures. The new luminaire will incorporate the Cycloptics highly efficient reflector design with the HID light source resulting in increased energy efficiency with equal or better lighting uniformity performance. Questions that will be answered include: a) What is the optimum number and distribution of Cycloptics luminaires b) How sensitive is the design to minor geometrical errors c) What is the potential energy savings with the new luminaire 3. Build and demonstrate the HID luminaire prototype. This objective employs a multi-segment fabrication and assembly process to produce the deep well reflector envisioned for the growth chamber application. Questions that will be answered include: a) How closely does the finished product geometrically match the design b) Are design modifications required to compensate for the fabrication method c) What is the estimated volume cost to manufacture the new luminaire 4. Determine the impact of the new luminaire on lettuce production. The optical test results for the prototype luminaire will be entered into the baseline growth chamber model. The effects of a fully populated growth chamber will then be calculated in terms of uniformity, energy efficiency and volume cost. The impact on the cost of lettuce growth will be estimated. Questions that will be answered include: a) Is the prototype luminaire a compelling replacement for existing fixtures b) What are the potential benefits of a second design iteration c) How can the reflector design be scaled to large area greenhouses APPROACH: Task 1. Establish baseline growth chamber model. To model the existing fluorescent luminaires in the chamber two commercial programs Photopia and Agi32 will be used. Photopia accepts standard IES (Illumination Engineering Society) files for the lamp and AGi32 is capable of modeling light reflections, both specular and diffuse from various surface types for given illumination source position and radiation characteristics. Together with a 3-D CAD drawing of the reflector and lamp,the radiation characteristics for the entire fixture can be calculated. The chamber lighting model will then be compared with and calibrated against the actual measured intensity data for the chamber. A thermal modeling effort will be carried out for the existing chamber. Luminaire manufacturer data will be collected to estimate the thermal energy produced both from the lamp and from electrical losses in the ballast. Chamber manufacturer data will be consulted to estimate the thermal load on the chamber. Task 2. Design HID luminaire. Due to chamber size considerations,a 400 Watt (or smaller) metal halide source will be used. Lamp selection will be based on PAR efficiency, heat generation, size, circuitry complexity and efficiency and cost. The lamp IES file will be entered into Cycloptics elumitech reflector design software. Reflector designs will then be generated that result in a uniform square intensity distribution at various axial distances from the reflector aperture. Reflector reflectivity will be assumed to be 95% and design efficiency will require at least 90% of all light rays from the source to only bounce once before leaving the reflector, ensuring minimum light loss to reflection surface absorption. Photopia and AGi32 will be used to determine the minimum number of HID luminaires required. Task 3. Fabricate, assemble and test luminaire prototype. Fabrication of the reflector will use established hydroforming techniques. Coating of the reflector will use established vacuum deposition techniques. The reflector material and thickness will be chosen such that heat resistance and dissipation requirements are met. A coordinate measurement test will be performed by the manufacturer to determine actual geometry of the finished part. This information is used by Photopia as an "actual" reflector, and the simulated optical performance compared to original design. Once the light source is attached to the reflector, independent optical testing will be performed by ITL(Boulder,CO.). ITL will perform planar and semi-spherical light intensity mappings at various distances using linear and goniometer translation stages. Spectral data will be collected to determine optical wavelength content and uniformity for each map. Task 4. Determine luminaire effect on lettuce production. The luminaire test results will be used in the plant growth model SUCROS to model impact on lettuce growth. This model includes effects of carbon dioxide, temperature and direct and indirect lighting. Energy and cost calculations will be carried out over the range of USDA climate zones. PROGRESS: 2009/06 TO 2011/05 OUTPUTS: Activities included visiting Philips Lighting and Philips agreeing to boost the PPF/W of their 315W ceramic metal halide lamp; visiting EGC (Environmental Growth Chambers) in Chagrin Falls OH to learn about the plant growth chamber market and their chambers. Dissemination during the project included ; multiple meetings with researchers at Cornell University in Ithaca, NY to share and discuss our research results and reflector design progress; meeting with Percival Scientific at Cornell University to discuss the retrofit of the test chamber; meeting with Rough Brothers in Cincinnati OH to gain their knowledge in the use of supplemental lighting in production and research greenhouses; meeting with The Kroger Co. to discuss how the performance of Cycloptics supplemental lighting for CEA (controlled environment agriculture) can benefit their west coast growers that are building CEA greenhouses to grow lettuce locally versus trucking from Mexico and West Coast. Cycloptics representatives attended the NCERA-101 annual meeting in March 2010 in Madison WI where Richard Tuck presented interim Phase-1 results and prototype development progress. They also attended the annual OFA conference and exposition in Columbus OH in July 2009, and LightFair, the international lighting conference and exposition, in May 2009 New York. PARTICIPANTS: Richard Tuck, the project PI/PD and Cycloptics CEO and Steve Mulder, Cycloptics Sr. Optical Engineer worked on the project. Together they designed the reflector and its CAD file that was used to build the alpha prototype. The prototype was sent to ITL (Independent Testing Laboratory), Inc. in Boulder, CO to generate the light distribution of the prototype to compare its performance to the computer model used to create the CAD file. Richard Tuck developed in AGi32 the simulation models that Cycloptics used to compare the theoretical performance of its alpha prototype to an incumbent T12 VHO fluorescent system being used in an 8ft x 12ft x 8ft walk-in plant growth chamber. TARGET AUDIENCES: Target audiences that were served by the research completed in this grant include NCERA-101 members in the Committee on Controlled Environment Technology and Use; plant growth researchers at the 100 US land grant universities and 673 agricultural research corporations; and the four major North American manufacturers of controlled environment plant growth chambers. PROJECT MODIFICATIONS: Not relevant to this project. IMPACT: 2009/06 TO 2011/05 During the course of the project Cycloptics realized it would need to use an indirect lighting method to achieve the desire uniformity throughout the plant canopy inside the test chamber. This resulted in Cycloptics requiring only fourteen reflectors with 315W ceramic metal-halid lamps to achieve average of 700 PPF (micro-moles/m2s) three feet below the lamps with a light barrier, and 850 without a light barrier, when modeled in AGi32 simulation software. This compared to to 278 Average PPF for forty-eight 210W VHO T12 lamps with a light barrier three feet below the tubes. Due to the engineering of a relatively larger fraction of indirect light, the optimal reflector design for growth chambers turned out to be less deep than anticipated. As a result, fabrication complexity and cost would be reduced. In particular, after checking with fabrication vendors, it was found that the reflector could be made in as little as two molding steps. This would have significant manufacturing cost benefits relative to deeper well designs, and would make the new reflector cost competitive with existing luminaires.

Greenhouse farming is an absolute necessity to revive and create local agriculture industries in northern climatically challenged regions with short growing seasons. Controlled Environment Agriculture (CEA) has made significant strides in greenhouse farming technology. State of the art CEA farming utilizes direct control of lighting, temperature and CO2 in a hydroponics environment. Key advantages of CEA greenhouse farming include reduced use of pesticides, faster and higher quality growth, minimal transport costs to local customers, and "vine ripened" produce with minimal spoilage and contamination risks. For CEA greenhouse farming to be adopted in rural northern climates, progress is needed to reduce greenhouse-operating costs. While temperature does play some role, lighting continues to be the most significant limiting factor in the growth of several specialty crops. Providing adequate amounts of photo synthetically active radiation (PAR) has been shown to increase greenhouse production capacity to a level capable of supporting large market demand. The challenge for northern climates is to implement such supplemental lighting systems at a cost that makes CEA greenhouse farming competitive with large out of state centralized farm and ship sources. In Phase 2 Cycloptics is combining recently available high intensity discharge (HID) bulb technology with its patent-pending, optimized reflector designs to achieve unprecedented plant growth lighting energy and cost savings. The new HID bulbs feature small emitters and high PAR efficiency relative to previous HID bulbs, making them ideal for compact and highly energy efficient growth luminaires. Cycloptics can design both direct and indirect lighting reflectors for these HID bulbs that can be precisely engineered to a highly uniform distribution over large arbitrary patterns and depths. HID bulbs have up to now been problematic as PAR luminaires for growth applications. Plants nearer the source tended to be burned, while others were not getting enough light. The design and optical performance of Cycloptics reflectors allow them to be placed closer to the plant canopy, enabling smaller volume highly efficient energy curtains for cooler months. The innovative compact reflector design will translate to less shadowing of natural lighting in warmer months. It is the combination of target efficiency, compactness, and HID lamp energy efficiency that ultimately yields the energy and cost savings for the proposed luminaire. OBJECTIVES: Cycloptics Technologies goals and objectives of its SBIR Phase 2 project titled "Next Generation Energy Efficient Supplemental Lighting for Plant Production" are 1a) Achieve the optimum forming and assembly method for a 315W ceramic metal-halide HID supplemental lighting reflector/fixture for installation and testing in a 96 sq. ft. walk-in plant growth chamber. 1b) Evaluate and contrast the energy efficiency and plant production results of Cycloptics 315W HID system of fourteen reflectors versus a fluorescent configuration of forty-eight T12VHO 110W lamps and forty-eight 50W incandescent bulbs, and a T5 system consisting of 108 54W bulbs and ten 50W incandescent bulbs in identical 96 sq. ft. chambers each growing Lactuca sativa, cv Flandria (Bibb lettuce). 2a Achieve the optimum forming and assembly method for a 315W supplemental lighting reflector/fixture for installation and testing in a research greenhouse at Cornell University in Ithaca, NY. 2b) Evaluate and contrast the energy efficiency and plant production performance of twenty Cycloptics 315W ceramic metal-halide HID fixtures installed in a Cornell University research greenhouse to existing 400W and 600W high pressure sodium and metal-halide HID fixtures. 3a) Achieve the optimum forming and assembly method for a 315W ceramic metal-halide HID supplemental lighting reflector/fixture for installation and testing in a CEA (controlled environment agriculture) hydroponic lettuce production greenhouse at Finger Lakes Fresh in Ithaca, NY. 3b) Evaluate and contrast the energy efficiency and plant production performance of forty Cycloptics 315W ceramic metal-halide HID fixtures installed over one bay at Finger Lakes Fresh in Ithaca, NY to their existing 600W high pressure sodium HID fixtures. APPROACH: Cycloptics will start Phase 2 by designing and testing new, sequential iterations (beta and gamma) of the alpha prototype reflector it completed in Phase 1 to establish accurate tooling factors and tolerances for the plant growth chamber reflector fabrication process. The optical performance of the iterative prototype reflector designs for a 96 sq. ft. chamber will be verified through independent testing to determine planar and semi-spherical maps using linear and goniometer translation stages respectively. Spectral data will also be collected to determine optical wavelength content and uniformity for each map. Directionality will be determined based on the light sensor characteristics. As a baseline for the Cycloptics luminaire, several measurements will be taken without the reflector installed in the walk-in plant growth chamber. The overall "wall plug" efficiencies with and without the reflector will also be measured, as determined by optical PAR output vs. electrical power input. Cycloptics will correlate test data with simulation results. Modifications to the luminaire model will be made, and a final layout of the luminaires for the growth chamber at Cornell will be prepared. Performance metrics will include lighting lateral and depth uniformity, and daily light integral relative to that required for lettuce. The PAR efficiency, energy savings, and manufacturing cost of the new luminaire configuration will be compared to that for the existing T12 configuration as well as to configurations based on next generation T5 fluorescent lamps. As part of the "bottom line" economic impact portion of the proposed effort, the estimated volume procurement, installation and operation costs of the new luminaire design will be estimated and compared with existing fluorescent luminaires. The target audiences for the research results that Cycloptics achieves in Phase 2 for its Next Generation Energy Efficient Supplemental Lighting for Plant Production are U.S. land grant universities, agricultural research corporations and CEA greenhouses, and similar entities worldwide. Within these organizations the groups that will benefit from the projected 50% energy savings for plant growth chambers retrofitted with Cycloptics supplemental lighting, and the 50% reduction in electric demand for both supplemental lighting and air-conditioning for new chambers manufactured with Cycloptics supplemental lighting are the researchers, facility managers, trustees and general management.