SPS Project Spotlight - Small Hunting Cabin Off-Grid Solar System

Yesterday a customer came into our office looking for a nice power solution for his hunting cabin. Initially, he had some questions about a pre-configured portable solar kit that he had noticed online. These plug and play solar kits can be a great choice for particular applications, but after speaking with him for a few minutes, the custom design wheels started to turn in our heads!

After  reviewing the customer's expected loads (what he planned to power), showing the customer some solar system components and examples of a few of our off-grid solar charging systems in our warehouse, we were able to get a great idea of exactly what he needed. Keeping low cost and high reliability in mind, our first system design ended up being a 540 Watt pole-mounted system with a 1000W 24VDC -  120VAC inverter. After providing him a quick quote and basic custom wiring diagram, we look forward to the next step with this customer and his installer to see if he would like to look into other options, such as using a larger inverter or possibly an inverter/charger for automated generator use.

As with many off-grid systems, there will probably be a few tweaks to our first design, but we are more than happy to work with our customers until they get exactly what they need and leave with a smile on their face and an extremely reliable system that won't leave them in the dark!

Here's the skinny on what we quoted for this customer, and some notes on what the customer can expect from the system.

Small Hunting Cabin Off-Grid Solar System - Parts List:

QTY: 2 - Peimar 270W 60 Cell Poly Solar Panel SG270P
QTY: 1 - Side-Of-Pole Solar Mount 2X 60-Cell Panel (SOP-Y)
QTY: 3 - HelioLug U Lug PV Lug with Hardware UL 2703
QTY: 1 - 50 ft MC-4 PV Cable Extensions
QTY: 1 - MidNite Solar 3 Circuit Combiner
QTY: 1 - MNEPV 20A PV Breaker
QTY: 1 - MidNite Baby Box
QTY: 2 - MNEPV 30A PV Breaker
QTY: 3 - Two Wire Cable Grip 6mm
QTY: 1 - MidNite Kid 30A MPPT Charge Controller Black MNKID
QTY: 1 - Samlex PST-1000-24 1000W 24V Inverter
QTY: 1 - 2-0 Inverter Cable 48in Red
QTY: 1 - 2-0 Inverter Cable 48in Black
QTY: 1 - Samlex DC-FA-200 Battery Post Fuse Block

Off-Grid Solar System Description.

This is a pretty straight forward 540 Watt 24 Volt system. The two solar panels will be mounted on a side of pole mount from our friends at General Specialties, one of the top-notch U.S. made racking companies we've happily worked with for a number of years. The panels are wired in series, so only a single solar panel extension wire will be required and the panels are fused at the array inside a Midnite Combiner box. The 20A PV breaker is intentionally oversized, the solar panels do have a max series fuse rating of 15A, but here in CO we have seen odd breaker issues in the winter time on pole mounted systems due to the high irradiance and an anomaly we call snow bounce. This 20A breaker is installed inside the Midnite Combiner. Not included in this parts list or wiring diagram, but something that we will also recommend is a lightning suppressor, which would also be installed at the combiner. Our favorite lighting arrester or surge suppressor for this is also made by Midnite Solar, the MNSPD-300-DC.

Wires from the pole will land in the Midnite Baby Box, a handy indoor breaker enclosure, which holds the two 30A breakers for the solar input and output from the MPPT Charge controller. An MPPT charge controller was used not only to step down the voltage from the panels wired in series, but will be better for wintertime production, which is generally when these small hunting cabins are utilized the most. This will feed a 24V battery bank, which the customer currently has but may be interested in upgrading, I'll make some notes below on a couple battery banks that would pair up nicely with the kit.

A 1000 Watt 24V - 120VAC Pure Sine solar inverter from Samlex can power their AC loads, and can either be hardwired to their electrical panel or used standalone with its two standard GFCI receptacles.

A system like this should charge around 1500 - 2700 Watt Hours into the battery each day in the winter time, this is assuming proper panel orientation and 3-5 hours of good sunlight.

We recommended a nice starter battery bank for this cabin solar system that includes four Trojan T105 225Ah 6V batteries. These would be wired in series for a 225 Amp Hour 24 Volt bank, with a total storage capacity of 5,400 Watt Hours.

Off-Grid Solar System - Wiring Diagram

Here's the wiring diagram we worked up for them to give them an idea of how all of the parts work together, we like to keep our parts list in basically the order you see them in our diagrams to make things as easy as possible!

We hope that this customer project spotlight will help inspire your own solar project!  Give us a call to explore what kind of custom solution we can provide for you!

Thanks for reading!