Passive Solar Herb Drying Project

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2016: $18,999.00
Projected End Date: 03/31/2018
Grant Recipient: El Milagro Herbs, Inc.
Region: Western
State: New Mexico
Principal Investigator:
Dr. Tomas Enos
El Milagro Herbs, Inc.

Annual Reports


  • Additional Plants: herbs


  • Education and Training: on-farm/ranch research
  • Energy: solar energy

    Proposal summary:

    The purpose of the Passive Solar Herb Drying Project is to build, monitor, and provide educational information about an effective design for dehydrating medicinal and culinary herbs for on-farm use. Tomas Enos of Milagro Herbs, Inc. proposes to build a passive solar herb dryer that utilizes sunlight and air for the purposes of demonstrating a cost-effective and time-efficient way to process harvested roots bark leaves, and fruits for sale. One of the difficulties that herb growers and processors have in today's market is the lag time in drying plant material from the field so that it can be packaged and sold in a cost effective time. The longer it takes to dry material the longer finished products are delayed and cash flow is compromised. Many crops utilized by Milagro Herbs and the herb industry at large are composed of dense material, like roots that require lengthy drying times and can render uneven results. This situation results in seasonal delays in drying and processing as many herb crops are harvested simultaneously and need immediate drying: a grower/processor is limited on space for drying and cannot make deadlines due to long wait times. Tomas Enos has worked in the solar energy industry for many years and is currently a herb grower, processor, and retailer in New Mexico.  Mr. Enos has developed plans for a modified solar food dryer from the New Mexico Solar Energy Association design and a solar lumber kiln dryer design, also built in New Mexico. The Passive Solar Herb Dryer proposed under this SARE application will be designed to operate without utility power and will dry valuable crop material in short intervals based on previous crop dryer projects built in New Mexico. The dryer design includes installation of a small monitoring station with thermocouples to measure outside ambient air temperatures during drying as well as nine internal thermocouples to measure temperature gradients and effic iency. The monitoring equipment will be powered by the sun. Mr. Enos will maintain records of the design and construction of the dryer as well temperature data for each of the selected 10 herb crops compared to time to finished drying. These herbs will be harvested from Mr. Enos' fam1 in southwest New Mexico and the surrounding area. Unique questions to be answered include l) what is the final quality compared to air drying; 2) recorded times to dry one pound increments of IO selected herbs and roots: 3) seasonal drying variations at the site; 4) internal versus external temperatures in the dryer . The educational outreach from this project will include: I) a one page fact sheet for interested processors; 2) printed and digital construction plans of the crop dryer: a website and Facebook presence to promote the benefits of solar herb drying to include video and written documentation: 3) data will be logged in to the website including processes and final results.

    Project objectives from proposal:

    Objectives: List of Objectives/Timelines I. May 15, 2016-Startup of Project and Grant Acceptance 2. June 15, 2016-Finish solar dryer design, materials list; order construction materials 3. August 1, 2016 - Dryer construction completed; monitoring equipment installed 4. August 15, 2016 - First crops harvested for drying; monitoring program begins; documentation begins 5. September l and ongoing- First year crops harvested, dried, recorded, documented 6. October 15 , 2016 - Educational materials ready for printing ; information from first year loaded to website; presentations made for first year results 7. November 30, 2016 - Review of first year results; modification of dryer, if needed; logging first year results and writing of first year progress 8. December I, 2016 and ongoing - Respond to ongoing request from interested producers and participants from outreach efforts; preparation for second year 9. March 15. 2017 - Begin harvesting and drying early spring crops; monitor, record results, upgrade educational efforts I 0. May l. 2017 - Ongoing drying of plants from leaves to fruits to roots: publication of results to paper and websites; distribution of information through all channels with Technical Advisor 11. September 15, 2017 and ongoing - complete profile for l 0 important herbs and drying results with 2 year comparison: publication of project results; presentation of results to workshops/conferences 12. December I. 2017 to project completion - update results, answer request for information, distribute publications and demonstrate success of project to agricultural producers and educators

    Relevance to Sustainable Agriculture: Relevance to Sustainable Agriculture I . Economic Viability - the soundness of this  project  in economic terms is related to the efficiency and  energy  savings over standard  drying  procedures  traditionally  used  by  herb companies.  Savings are accrued by faster drying times and faster processing which will enable Milagro Herbs and other herb growers to tum over inventory for sale in larger amounts at faster intervals. For example, Osha root (Ligusticum  porteri), a  popular root harvested  in the Rocky  Mountain  region, can consume  up to 4 weeks in standard open-air drying , with uncontrollable results. Some growers utilize supplemental energy like gas or electric heaters and circulating fans to speed up the process, thereby incurring additional costs. The proposed design will use no additional energy other than the sun and will produce faster, more uniform results. 2. The project will use construction material with a life of over 20 years; the dryer will not require any operating costs. The Passive Solar Herb Dryer will demonstrate how using the sun and natural air convection optimal drying can be achieved for a wide variety of agricultural products. The size of the dryer will be manageable as 4 foot by 12 foot and 6 feet in height cabinet / facility, thereby allowing easy accessibility without extra equipment. 3. This is a socially responsible project as it takes into account the well-being of farmers and agricultural producers as well as small herb operations in rural areas. Cost effective means of operating are of vital importance in maintaining productivity, profitability, and rural lifestyles. This project addresses the hands-on practical approach to using renewable energy while teaching others how-to live self-sufficiently .

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.