Off-Grid Solar System For Sheep & Cattle Ranch

Level 3 – Off-Grid Solar Energy Generation, Storage & Distribition

Level 3 – Design & Implementation

Location: Santa Maria, CA

Project Scope: 7th Generation Design was invited to design for and oversee the implementation of a high-efficiency off-grid energy system to serve the various needs for moving electricity for a 100% grass-fed meat business.

MagnaSine Inverter next to power supply and charge controller
Direct Current Feeder Circuits and Branch Circuit Over-Current Protection Device Schematic. Since there were DC loads, we also included a Victron DC low-voltage disconnect, which will disconnect power to the DC loads if the battery voltage gets too low. The AC inverter has a built-in low voltage disconnect for the AC loads.

Work Performed

  • Site Assessment
    • Identification and assessment of existing energy sectors passing through the site (solar, wind, water). A solar photovoltaic (PV) array-charged battery bank was determined to be the most appropriate electricity conversion and storage technology.
  • Needs Analysis
    • Facilitated a needs analysis process with the residents to determine their minimum needs for energy at the homesites while still maintaining their desired quality of life.
  • System Design
    • Specified end-use components (including lighting, cooking, refrigeration, heating, computing- and communications-device charging, laundry, and tools) that would provide for the residents’ needs. End-use components that utilize direct current (DC) electricity were specified wherever possible to match the output of the solar PV array and battery bank and thus maximize efficiency and minimize cost.
    • Designed DC branch circuits to distribute electricity from the solar PV array and battery bank directly to the various DC end-use components throughout the barn, shop, and office.
    • Designed alternating current (AC) branch circuits to distribute electricity from a 4.5kW pure sine wave inverter to the AC end-use components (laundry equipment)
    • A 3.5 kW solar PV array was selected to convert the site’s sun supply to DC electricity, and a 21 kWh 48V lead-acid battery bank was selected to store surplus electricity produced for periods without sunshine.
    • Proper safety considerations and component protection devices were implemented throughout (including fuses, breakers, low-voltage disconnects, and grounding).
  • Implementation Oversight
    • Materials acquisition and preparation as an authorized dealer/installer for Backwoods Solar.
    • Solar PV panel array mounting atop corral shade structure and trenching of feeder wire to charge and control center in nearby structure.
    • Installation of battery bank, solar charge controller, DC-to-AC inverter, AC-to-DC backup generator charger, and necessary fuses and breakers in laundry shed power center.
    • System commissioning.
The shipping container barn. We considered mounting the solar panels on the gabled roof but the sloped sides were not oriented correctly.
First sketch of solar array support structure, with sizing constraints for 3.5kW PV array.
AC and DC feeder circuits were run from the main distribution panels to subpanels in each area.
The solar PV array was installed on top of a custom support structure installed by the owner. This support structure will be integrated with the boundary fencing of future livestock corral, and the solar array will provide shade to livestock (stacking functions!).
Running heavy gauge cable through the container barn rafters to power the many chest freezers that keep Outlaw Valley’s beautiful grass fed meats frozen and ready for customers.