Progress report for FNC25-1451
Project Information
My name is Rebecca Gentner, and I am a small-scale farmer and agriforestry enthusiast based in the remote Keweenaw, Upper Peninsula of Michigan. For two years, I’ve operated a 60-acre sugar bush with a focus on sustainable practices, particularly in maple syrup production. I’ve gained hands-on experience with gravity-fed sap collection systems and sustainable maple syrup production methods. I’ve also learned the practical skills needed to adapt to rural areas, including how to maintain and repair equipment, install household solar energy systems, and overcome logistical challenges associated with off-grid operations. My goal is to expand the operation’s productivity while promoting environmentally responsible farming.
I currently tap 250 maple trees and am dedicated to finding innovative solutions to improve efficiency and sustainability, especially in off-grid, rural areas. I am deeply committed to knowledge-sharing and have hosted farm tours and local workshops to help others implement sustainable practices. I believe in the power of community and aim to provide solutions that help fellow small-scale farmers thrive. In addition to syrup production, I engage in sustainable forestry practices, vegetable farming, and support the local food economy through sales at farmers' markets. The farm operates entirely off-grid, utilizing solar panels and wind power to run the operation. This lifestyle aligns with my vision of a sustainable, resilient farm that can withstand the challenges of rural, off-grid living in an ever-changing climate.
The project funded by this grant will help us double maple taps and implement solar-powered vacuum pumps to improve sap collection efficiency. It will also enhance farm accessibility, allowing us to host educational events and share insights with the local agriforestry community. This project is a step toward building a more sustainable, scalable operation that can serve as a model for other small-scale farmers in remote areas.
The traditional sap collection method, using metal spouts (spiles) and buckets, is simple but labor-intensive. It can also be impractical in areas with heavy snowfall, variable terrain, or where municipality utilities like water or electricity are unavailable. In contrast, gravity flow lines, a more modern approach, use tubing to transport sap from the taps to a collection tank, eliminating the need for buckets. While more efficient, gravity flow systems have their own challenges. For example, gravity flow systems still depend on the natural freeze-thaw cycle to generate pressure. If the weather is inconsistent or there’s an early thaw, sap flow can become unpredictable, limiting system reliability. Moreover, the tubing layout must also be carefully planned to ensure proper flow, which can be costly and complex, especially over large distances or uneven terrain; gravity-fed 3/16-inch lines require a 50-60 foot elevation drop from the first tap to the collection point to generate sufficient pressure to flow. Without this natural gradient, producers often rely on commercial sap vacuum pumps. However, these pumps are expensive, complex, high-energy demanding and designed for large-scale operations, making them impractical to beginning, rural, or small-scale producers.
Post-grant approval allowed Tree Hugger Maple to purchase the necessary equipment in Fall of 2025 to install the solar pumps.
The pump system was assembled and then placed into an insulated plastic tote to avoid damage in case of thermal failure. Spring of 2026 will be the first attempt at integrating the pump into the existing system, but the weather has not cooperated for a voyage into the sugar bush at this time.
Winter of 2025 time was spent managing the existing lines. What that means is, I have skied into the property-which during the winter is inaccessible by road-and pruned dead limbs from the trees, cleared brush from interfering with the proposed path of new lines, and maintained the existing lines by patching any breaks in the tubing. Before the deep snow arrived I was able to string up the main pipeline between 6-ft T-posts. It has since been covered again, but in the coming spring this will make adjusting the line significantly simpler as it will need to be uncovered from a shallower depth. The Keweenaw is experiencing a track to record-breaking snowfall winter 2025/26 with 200in already in January. Significant planning is needed to move material out to the sugar bush.
A solar pump offers an ideal solution for small-scale producers who want to increase sap collection without the expense and complexity of larger, commercial vacuum systems. For under 1,000 taps, installing a 12-volt solar-powered pump system provides an affordable, environmentally friendly alternative.
The system includes a diaphragm pump designed to handle up to 300 taps (4 gal/min). It will be spliced into the existing 3/16-inch tubing and connected to the pipeline. To protect the pump from the elements, it will be housed in a plastic tote. The system will include a filter for debris, a bypass valve, and various fittings to adapt to the pipeline. Additionally, a bus bar and temperature controller can be added to activate the system automatically when temperatures rise above freezing and shut it when below to protect the circuitry. The controller will allow the system to run only during optimal conditions, ensuring efficiency.
The system will be powered by two 100-watt solar panels. Placed at a 45-degree angle with southern exposure, they will provide enough power to run the pump and charge the battery. Each panel takes up about 6 square feet and will be mounted on plywood and a utility sled for easy transport. The solar charge controller ensures that the battery is properly charged, and all wiring will be done using durable 10-gauge wire suitable for outdoor use.
This setup is especially beneficial for remote locations where larger, traditional vacuum systems are impractical. The diaphragm pump can withstand freezing and thawing temperatures, making it ideal for maple sap collection. It is also capable of running dry without damage, which is crucial for times when sap flow is limited or interrupted. If the pump fails, the sap flow can continue through a bypass line, minimizing disruptions.
The solar-powered vacuum pump can be integrated into existing sap lines and will be tested starting in Fall 2025. The goal is to evaluate how the system performs under different conditions and compare it with the baseline gravity-fed collection system.
Carefully recording the volume of sap collected and syrup produced under each system, I can track efficiency, cost-effectiveness, and long-term operational expenses. The data will help determine the sustainability of solar integration in maple sap collection systems, including initial setup, maintenance, and long-term savings.
Once the data is collected, the next objective is to share it with the broader agriforestry community. In Spring 2026, the farm will host a field day to showcase the results and educate others on the benefits of solar-powered sap collection systems. I'll share research results and design knowledge of the installation process, performance and greater challenges learned.
The portable pumps can also be demonstrated at local educational events, allowing participants to learn how to tap trees, set up the system, and adapt similar solar solutions for their own farms. The local farmer’s market committee has expressed interest in presenting the solar pump method at the market, where workshops will allow people to tap trees and learn more about this innovative approach.
Research
Diaphragm pump, lines, electric, all materials purchased and assembled. Two diaphragm pumps, designed to handle enough 4 gals/min of flowing sap were purchased as well as bypass valves, adaptors, and food grade 3/16-inch lines to splice the new system into the existing lines. All of the electrical equipment - thermal breakers, buses, 12v relay, and solar panels and power controllers - were researched and purchased with the assistance of Sap Happy Sugarin’ Supplies. Utility sleds and plastic toting were all donated by myself in kind and have been reflected in the budget. These materials were chosen due to their adaptability to the existing project. New materials were simply adapted to match the existing system.
The pump system was assembled and then placed into an insulated plastic tote to avoid damage in case of thermal failure. Spring of 2026 will be the first attempt at integrating the pump into the existing system, but the weather has not cooperated for a voyage into the sugar bush at this time. The temperatures are too cold to attempt adapting into the existing framework. As this winter is on track for record-breaking snow and cold, plans are in the works to have back-up supplies to repair any unforeseen problems with the pumps. Safety and foresight are paramount when traveling off-grid into deep woods, I’m gathering any excess supplies to repair unforeseen problems with the pumps. Any extra trips into town are looking less and less feasible.